Tweaking for the better is
hard. Whenever we invest a lot of effort on improving
things, we start preparing our minds for the success and
may have a hard time evaluating the objective outcome of
our project. And at the end of the day, the objective
outcome is only a matter of statistics. If a majority of
people think it is a failure, there's not much we can do
about it. Have we made the best car, wine or amplifier if
nobody buys it?
When it comes to something as subjective as sound, it may
be even more difficult.
DTQWT
tweaks is a page describing some of the things
I've tried over the last couple of years to possibly
improve the sound of the TQWT and DTQWT constructions.
Launching the TQWT mkII and DTQWT
mkII has indeed been given some thought. The
kits have sold in considerable numbers and customers may
wonder if they have an out-dated product. My best advice
is this: If you like what you have, stay where you are.
If you have box of coil/caps leftovers, the tweak is easy
to try out before buying expensive caps and coils
although the investment is modest.
In the DTQWT tweaks file you can read
what it's all about. Extensive listening tests and
positive response from visitors made me certain the tweak
was worth the mkII extension.
The launch of the TQWT mkII and
DTQWT mkII follows closely the QUATTRO release. If 40
liters is more acceptable than 120-150 liters, this may
be a way to get the 8008/TW034 sound without upsetting
family life.
Due to experiences gained during the QUATTRO work, both
the TQWT and DTQWT crossovers were revised to include
these latest developments, and the choice between the
QUATTRO and TQWT is really a matter of size - where DTQWT
will take the lead due to overall soundstage and low-end
extension.
What interests me the
most right now is whether people will build the
QUATTRO. The construction is based on a lot of requests,
but the diy-community is a tricky niche segment. It may
want a lot of things, but when it comes to actually
buying, things may be different. Time will tell. Sure is
that this 40 liter bas-reflex design is going to be one
of my - few - stock speakers.
16 June 2010
The AudioTechnology based PRELUDE was a long
journey into some new territories and as should-be, a
learning experience. Based on history, very few people
will build this speaker due to overall cost but maybe
some of the ideas can be built into similar designs based
on lower priced drivers. Time will tell.
On the to-do agenda is a 40 liter bass-reflex design from
the JA8008/TW034 drivers used in TQWT and DTQWT. Many have asked
for such a design and I'm curious myself how it will
perform. A center speaker with the same drivers is also
included in the to-do list. Both these projects will
require some time as I have to make nice looking cabs -
and it takes time.
Appearance is critical
for any speaker design. If it looks crappy, nobody will
build it. The Jensen speaker has that
problem. Being the best ScanSpeak construction on these
pages, it has zero feedback from people actually building
the speaker. Raw MDF panels simply don't turn diy people
on.
I recently sold a pair of beautiful oak-veneered speakers
and buyer's spouse was truly unhappy with the prospect of
having these ugly monsters in the living room. Taste
cannot be argued, but I'm sure a lot of people could have
better sounding speakers if design wasn't such a critical
parameter. The skinny towers requested by most people are
not necessarily ideal from an acoustic perspective. If
instead of a 30 liter floorstander we allowed a cabinet
size of 100 liters, we might get better sound from
cheaper drivers. Large drivers don't have to move much
and distortion is reduced compared to the poor 6"
driver that has to deliver deep bass and smooth midrange
at the same time.
The Chario Sonnet
"review" was an interesting break from
speaker building and gave some new ideas that will be
tested in the future. A 34 mm dome has been modified by
vented pole piece and voice coil to produce a smooth
response down to 1 kHz and will be used for experiments
with points of crossover in the 1-2 kHz range. Something
I never found 1" domes being able to do properly.
Vintage speakers still
keep me interested and the greencones are being
investigated for the time being. Reproduced music can be
enjoyed in numerous ways and as long as we don't push
light-weight paper cones too hard, some enjoyable moments
can be had.
21 April 2010
I'm
pleased to have added the NOMEX 164 construction to
my website. This speaker delivers a midrange that
qualifies the midbass drivers for use in even bigger
speaker systems as a dedicated midrange driver. Pity
Peerless doesn't make an 8ohm/90dB/10inch version of the
same. A 10" NOMEX, the 5.25" NOMEX middriver
and the HDS tweeter might make a powerful, classic 3-way.
The 10" SLS driver doesn't quite make it.
Having
set up the NOMEX 164 construction,
four SEAS CA18RNX drivers were at hand and would fit the
front panel without further woodwork, thus the SEAS
CA18RNX construction. Another 2½-way featuring
SEAS 27TDC tweeter. As for the NOMEX 164, we get an awful
lot of sound from a modest investment: Twice the power
handling, twice the sensitivity and overall lower
distortion compared to a single 6" driver having to
do it all.
The
Audio Technology PRELUDE is in progress.
3 pairs of different 15H52 middrivers are being tested
and I think I have a candidate. Having the middriver in
place more tweeters have been simulated and there may be
changes. Hopefully this project will be launched over the
summer. So far, it's going to be the most costly speaker
I've ever launched.
New
drivers: I often have requests on specific
drivers and given the vast amount of drivers available, I
can only cover a fraction of them. New drivers are often
brought in by diy'ers needing a crossover for their dream
speaker and a 3-way from the SS Illuminator 18WU may
appear some day, possibly with the new SS Discovery 10F
for mid and HIQUPHON OWI for treble. Based on history I
know a lot of diy'ers give up when it comes to cabinet
construction, so let's see.
I had the opportunity to measure the SS 15WU drivers some
months ago and I certainly wasn't impressed. With dips in
the 1-2 kHz range and peaky like hell in the treble range
it was very hard to model and the guy bringing them in
immediately sold the again. The 15WU8741T00 does some
83.5 dB/2.8 volts where the good old Revelator
15W8530-K00 does a healthy 85.5 dB/2.8 volts. And the
18WU8741T00 does 2 dB less compared to the venerable
18W8531-G00! Generally it appears SS has gone another
step down the latter in reducing efficiency! Even Qm has
gone down.
Vifa (Tymphany) has launched new drivers based on fancy
chassis and one-piece molded paper/wood cones, Vifa
Innovation, all 4 ohms drivers and the NE180W-04 looks
interesting. High Qm, high sensitivity (due to low
impedance) and a frequency response that doesn't look too
bad. BUT... only 133 cm^2 membrane area, not a driver
that can match the SS 18W Revelator. The 10" driver
NE265W-04? Only 88 dB despite 4 ohms impedance. Too heavy
cone. Hmm......none of these Illuminator or Innovation
drivers make me drool.
What looks more interesting is the Discovery range from
ScanSpeak, in particular the 10F middrivers. The 6"
drivers won't deliver the deep bass of the 18W8531G00
drivers but some of these drivers should make crossover
work very easy.
Other drivers people have been asking about are the
SBAcoustics units. Looks interesting and very decent
prices too. What didn't thrill me so much was the
frequency response from some of the drivers, e.g. SB17NRXC35-8. Nice response
up to 3 kHz, then all hell breaks loose in the 4-10 kHz
range, although the impedance profile suggests nothing
serious is going on. Cone geometry? I'm not saying it
makes a bad driver, but most likely a profile like this
will take special measures when doing the crossover. Very
nice TS data by the way.
I did buy some speakers this winter: The Beyma
12B100R bass drivers. 94 dB. Not sure where they end up,
but some high-efficiency 3-way - some day. And I bought a
pair of Audio Technology 6I52-12-06-SD drivers too. Very
special drivers. Light-weight cones and 92 dB
sensitivity. Not sure where these may end up either.
A
center speaker based on JA8008/TW034 drivers is
in preparation. Quite a few people have asked for a
center speaker for their DTQWT speakers and not being a
surround fan, I've been reluctant - or just plain
lazy...sometimes I need a break from building speakers -
to find new directions.
01 March 2010
It's
been a long and cold winter and people in
Scandinavia and the Northern Europe - based on response
to my website - have spent a lot of time in the workshops
building speakers. Apparently there's no economic
recession when it comes to diy speakers.
Fortunately our local symphony orchestra have made great
performances to cope with the dark and the cold, thus
Mahler's 9th the other evening. Moments of intense beauty
in particular 1st and 4th movements. One of my neighbours
is a bass player in the orchestra and from time to time
they may not be playing and have free tickets for the
concerts and what he told me from taking advantage of
this was quite a surprise. Sitting among the crowd he
really thought things sounded crappy! Nothing compared to
sitting on the podium with all the musicians around.
Well, well.... We have a great concert hall and nothing
wrong with the acoustics. Thus, for Mahler's 9th I bought
tickets on 3rd row - to the left. This is like 3-4 meters
to the nearest violins and I think I got an idea of what
he meant. From this position the orchestra is a listening
angle of more than 90 degrees and to be honest, sonically
it's not ideal. But it certainly gives you quite a
different auditive perspective and ability to hear
details from all the instruments adding to the overall
sonic painting. Great evening. Next in March is Nikolaj
Znaider - and his Strad. Late this year Renee Fleming is
visiting town and I've bought tickets. And speaking of
concerts, Diana Krall was in town recently. Great music
and poor sound. Her Steinway just sounded like a plastic
Yamaha. Shame on the PA guys who did this.
What
else has been going on in my workshop
these recent months? From the most recent files, Study on
stepped baffles with little impact on tweeter
performance., Siri's
Killer Note, it may shine through I've taken
a deep look in the practicalities of making 1st order
Butterworth filters. Actually it seems clear that it's
easier to make a 3-way 1st order crossover compared to a
2-way. Nevertheless, the last month I've been listening
to eight crossover versions of a small "6+1"
monitor. In reality this can go on forever trying to
improve phase integration and frequency response from
changing the stepped baffle, tilt of cabinet and
subsequent crossover mods. What seems mandatory is proper
phase integration between 1-10 kHz. Reversing tweeter
polarity we need a decent suck-out between these two
extremes and things appear to start sounding right. One
octave below and above point of crossover isn't quite
enough. My best guess at this stage is 1½ octave and
we're safe. It either takes drivers with exceptional
linearity - or a lot of equalisation via notch filters.
Don't be frightened by 3 notch filters in shaping the
roll-off of the midbass. Fortunately these are in
parallel to the driver and sometimes do very little - but
may improve phase integration considerably. What also
seems clear is that amplitude irregularities (linear
distortion) are much less noticeable when drivers are
driven from a 1st order Butterworth filter. Well in
accordance with the findings of Vandersteen, et al.
Currently
I have this monitor in our living room run by
the JungSon and I like what I hear. I've listened to more
classical music from these speakers than I use to do.
Audience clapping - as always a great tool for evaluation
of speakers - are improved compared to high-order
filters. Clapping sounds darker with reduced impulse
distortion. Sibilance is much more tolerable, which is
great! Sibilance is a much too common problem due to poor
stage microphones and singers having a much to close
relationship to their mics. Next to this any sound of
acoustic instruments seems improved and more natural with
regard to timbre.
The drivers used are an 18H52 from Audio Technology and
SEAS T29CF002 tweeter. Hopefully this will construction
will be launched some day. I need an 18H52 driver with
higher efficiency than the one currently in use and will
probably have a 4 ohms version built.
All this is taking place while I wait for the final
midrange drivers for the PRELUDE. This has taken
much longer than anticipated.
Oh
yes, I've read Michael Fremer's review of
Vandersteen Model 7 speaker (Stereophile, March 2010).
The ultimate impulse and phase coherent speaker system
with proprietory cones made from balsa wood and carbon
fiber. I've been looking forward to this. Fremer says he
could live happily ever after with this (45,000 USD)
speaker system and only reservation is the lack of
visceral slam from ochestral climaxes. No wonder, this
speaker claims 85 dB sensitivity and Atkinson measures 84
dB. All this work and 84 dB
sensitivity...Vandersteen must be really keen on keeping
size small and bass extension deep.
01 Dec 2009
It's been two months since last speaker's
corner and November was indeed a busy month of diy. Many,
many mails with no particular theme, rather comments and
questions regarding a wide range of constructions found
on this website. Quite a few people have visited the
10C77 pre-study and the PRELUDE is up and running
although not yet with the final midrange. The target
sensitivity of the midrange has been handed over to Per
Skaaning of AudioTechnology and hopefully I'll have the
drivers before Christmas. In the meantime I can sand and
oil the cabs.
Regarding frd and zrd files for
speaker simulation: I do not provide these files from my
LspCAD library. I have done a few times and people
sometimes get all sorts of funny results and I do not
have time to discuss how to use the files correctly.
Sorry!
Looking at website statistics
is always interesting and I'm surprised how many hits the
L100 and Spendor BC1 have. The BC1 scores high month
after month and apparently holds a huge audience seeking
information. I have two front panels waiting for a BC1
refurbishing, which will probably turn BC1 lovers away in
disgust, because I'll transform the cabs into solid,
well-braces cabs, flush mount the drivers and make a new
crossover.... How about that? I took the speakers to my
livingroom recently and what a sluggish and un-precise
bass performance. We should be able to do a little better
here. For all the thin-walled cabinet is supposed to do,
don't forget it also meant low weight, reduced production
cost and not least, reduced transport costs. I don't
think we should be too blue-eyed here.
Asking for contribution to the
website was certainly not something I'd ever
considered until my webhotel gave me three options:
Reduce file size/upgrade to superpack/get lost! This is a
little more polite than last time where my former
webhotel just shut down my website without any warning.
Who are these people running webhotels? Robots?
Apparently they don't have names and they like to express
themselves in one-liners. I mean, I have no interest in
annoying these people and something like "Mr.
Gravesen, your traffic is exceeding so and so many
GB/month and you need to udgrade you hotel." No
problem! Of coarse I will.
The problem is that you guys have downloaded more than
200 GB per month and the Wharfedale brochures are a heavy
burden, but reducing the file size here would not really
solve the problem. Generally I post a lot of high-res
images and there's no way I'll reduce the quality here.
Seeing is believing and so it's going to be.
11 Oct 2009
Making a crossover and connecting
the drivers right may not be as easy as it seems
from a quick look at the crossover schematics. I steady
flow of emails from first-time diy'ers suggest that
reading this file may be a good idea: the
importance of wiring crossovers correctly.
I recently had a response from a DTQWT builder
complaining about the bass being weak and after a few
mails back and forth, it turned out the upper bass driver
wasn't connected and the lower bass most likely connected
with reverse polarity. No wonder it didn't play much
bass. So, read the files carefully and check your wiring
over and over again. There's no pointing fingers here! I
often find errors in first-time speaker set-ups. Having
measuring equipment is usually quite easy to find out
what has gone wrong. If you're a diy'er with no measuring
equipment, the only thing you can do is taking extra care
in construction of the crossovers and speaker wiring.
I'm pleased and proud to
have the Audio Technology 2-way back again on the
website, now with the SWANS RT2H-A planar tweeter in
replacement of the Raidho planar tweeter. Read here about
the new AT-SW.
And I've been visiting Audio
Technology to pick up the 10C77-25-10-KAP
10" bass drivers with the new sandwich cones.
Initial measurements suggest a 45-55 liter cabinet volume
and a decent response down to 30 Hz. The sensitivity of
the driver suggests a system sensitivity of 90 dB being
possible. A pre-study has been done to gather information
on performance before cutting sheets: 10C77.htm
 
Click images to view large.
These bass drivers are some chunky
beasts weighing more than 8 kgs each.
Measurements suggest a flat response up to 1.5-2 kHz and
for fun I tried modelling a two-way system with a point
of crossover at 800 Hz. No problem at all. Next I'll do
some measurements to compare the drivers with ScanSpeak
26W/8861T00 and SEAS W26FX002.
11 Sept 2009
In June's Speaker Corner I made
some comments on boring "6 +1 inch"
speakers and I won't change a word of what I wrote.
However, a recent standmount speaker project
incorporating an Audio Technology Flex Unit
6A77-25-10-KASD (4 ohms version) got me exited again on
small speakers. This driver features a generous 3"
voice coil former being a composite of both aluminium and
kapton. Now, having some 174 square centimeter membrane
area, this driver falls well in between a 6 inch and an 8
inch driver but I think it will be hard to find any other
8" driver that can truly match this driver when it
comes to power handling, dynamics and resolution. It's
phenomenally good and should you ever wonder if
high-priced raw speakers are worth while, not to forget
premium crossover components, this may be the one can
demonstrate that proper design pays off.
The 6A77 driver is mated with an Accuton C44 upper
mid/lower treble driver and the well-known HIQUPHON OWI
tweeter. Placed in a 23 liter vented cabinet I don't
think you can find a "bigger" speaker at
similar size. From a 4th order LR filter crossing over at
800 and 4500 Hz, this true monitor delivers a scaringly
level of transparency and is currently a great tool for
telling me which of my amps really aren't that good. It's
sounds magic from my 8 watts 300B amps, but obviously at
low level. 20 watts SET does better but 50-100 watts is
what it takes to make this speaker sing from its 2 ohms
minimum impedance. Only bad I haven't got any 100 wpc amp
that can match the 300B midrange.
Up-dating the ATR and ATR25
constructions for the new SWANS planar tweeter
obviously made we wonder if this high-sensitivity planar
was suitable for the DTQWT design. For a couple of months
I had the set-up running thinking it was work done! It
took an old friend to tell me this really wasn't as good
as the old one. Being your own hardest critic is not
always easy. Thus the DTQWT goes on as-is and is my
reference speaker. I have made drawings for 1.5 meter
tall version for 10" and 12" bass drivers, but
when they'll see light is hard to tell. Woodwork takes
time.
And no, I
have not tried the RAAL ribbon and
I won't. I think I have a mail every second day if I have
tried this ribbon. I've tried a lot of alu ribbons and
generally find them suitable for metal cones and some
polyprop cones as well. For paper pulp cones - generally
not a good match to my hearing. Planars usually goes well
with polyprop and sometimes (heavily) coated paper. Alu
domes for alu midbass drivers and sometimes polyprop or
coated paper. Good softdomes goes with everything without
always making the perfect match. Very little
experience with ceramic domes.
I find driver integration more important than having a
tweeter that may excel on single parameters like speed
and resolution. Two drivers must make a good sonic match
to produce a coherent sound. Trade off may be lack of
resolution, but so be it. No speaker is perfect anyway.
08 July 2009
View/hear the lectures by Daniel J. Levitin at Microsoft facility.
16 June 2009
Setting up the Summer-09 open
baffle project, the OB9, from JA8008/TW034 + Eminence
15" bass drivers made me realise how utterly boring
conventional speakers can be. How can I ever make a
6" + 1" midbass-dome-thing again? I will
be doing it, actually a lot of them, but it takes a
little time to recover and see the fun in small, boxy
sounding and un-dynamic speakers again. Most speakers
simply cannot even come close to rendering the true
dynamics of an upright bass the way a 15" driver on
an e.g. open baffle can do. Small speakers may to some
extent be emotional engaging, but only when we
hear a really large bass driver on an open baffle - or in
a horn - do we also get the physical engaging
sound we're longing for. We finally get the "punch and
the drama"! The
featherlight kick in the stomach - and we're looking at
the bass-drivers to see if the cones are thinking of
leaving the chassis' - and they're certainly not. They
barely move at all. Magic! With a total of 1700 square
centimetres membrane area, things start to work out. No
wonder some 130-150 cm^2 from a single 6" driver
can't do much. Even a 2½-way system from 6" drivers
won't count for more than a total of 500-600 square
centimetres.
A rather big ScanSpeak
construction has been launched recently, the Jensen, from 10"
ScanSpeak bass driver, well-known 18W/8531-G00 for mid -
and the 18W has never sounded better - relieved of
pumping air and at the same time trying to cope with
upper mid and lower treble. Goes well at modest sound
levels, but here we render the full potential of this
fine driver. Last but not least I was pleased to get
first-hand experience with the 9900 tweeter. It's great,
the best Revelator I think and on level with the
excellent SEAS T29 domes.
The DTQWT is doing well and
a lot of kits have been sold and I'm looking forward to
receiving comments and pics from the buyers. I've had a
number of visitors for hearing the DTQWT and the response
has been good. Whatever people bring of CDs and LPs, the
DTQWT will play it all. From classical music to the most
outrageous heavy metal stuff.
I never thought a 150 liter construction would take off
the way the DTQWT has been doing. This is not a
particular small speaker, but it seems to fill a gap for
high-efficiency speakers, which was my basic motivation
for initiating the project and having the 8008 driver
made by SEAS. The 8008 is the heart of the system and so
far its versatility is by far exceeding my expectations;
the TQWT, DTQWT and most recent,
the OB9. It takes time
to develop new constructions and with the help of a
potential JA8008/TW034 customer, a 2 x 12" version
may be realised within the next year. This will be a 300
liter brutto volume monster and if I had the space, I'd
build a pair for myself.
My new line stage project, 5687, is coming to an
end, and the hum-war is on hold from the final version.
The DTQWT system is not totally free of hum yet, but now
it's one of the Audio Mirror amps that needs some
attention. The blessing of home-made electronics...
I feel urged to comment on the
quality of some recent Verve vinyl pressings
from the US. Diana Krall, Anthony Wilson, etc. 180-200
grams "super" pressings and the vinyl surface
is crap. Visually blurred and sometime so noisy it's
looks like it's been taken hot from the mold and thrown
into its sleeve. How come? Who's pressing these LPs? Has
anyone experienced the same thing?
Shipping it back to seller (Elusive Disc, US) just
doesn't pay off.
08 April 2009
It's been a busy winter with quite
a range of SEAS constructions and Scanspeak
crossover for speakers coming in from diy people here in
Denmark. Check ScanSpeak
constructions and SEAS
constructions on intro page.
And some more ScanSpeak constructions are in preparation
for crossover: Three big speakers from ScanSpeak drivers:
2x21W/8554-00+15M/4531-K00+XT25TG
(Mark21), 26W/8861T00+15M/4531-K00+9700
and 26W/8861T00 + 18W/8531-G00 + D2905/9900 (crossover
done; still need to do some writing and box size
simulation). If they turn out good, they may pop here on
the website. Mark21 already there.
These early days of April
the temperature has risen to some 15 deg. C and it's time
for spending time outdoor, digging the vegetable garden
and getting rid of the garden debris from five long
winter months. Speakerwork will slow down for some
months. Not least due to amplifier building although an
open baffle speaker is on the to-do list; the summer
fun-project, like the OB7. This time OB9
from 8008/TW034 and a 15 inch
bass driver.
Identifying bottlenecks in
our systems is a never ending exercise. Few years a go I
had a guy visiting with all his silver interconnects and
silver speaker cables and we weren't able to hear any
difference comparing these to my rather mixed blessing of
cables. Not at all. The set-up at that time was a modded
Rotel CD player, Audio Research SP16L line stage and
Copland CTA505 power amp. I don't recall the speakers at
that time.
I recently took the time to make a silver cable from my
LINN tonearm to the RIAA and later silver cables for RIAA
to 5687 line stage and from line stage to Audio Mirror
mono blocks - and well, here it was. Midrange
transparency improved with reduced smearing of detail and
a midrange presence I didn't think possible. The silver
cables are all made from 0.4 mm pure silver in teflon
tubing and all are shielded being wrapped in aluminium
foil. Basically good interconnects should be able to
improve the sound in any system, but I guess overall
quality can be so compromised that adding silver cables
just doesn't come through. Timing is important to render
all qualities of the never ending tweaking process. *
Once and a while we may be
fortunate borrowing a piece of gear that may
identify a true bottleneck in our system. The 5687 line
stage with output transformers was such a piece
of equipment, originating from diyhifisupply in HongKong as
the TRAM w.o.t. line stage. Product is discontinued,
probably due to cost of output transformers - or maybe
hum problems, because the original TRAM has some serious
hum problems only realised when you run real
high-efficiency speakers. Cloning the TRAM isn't
particularly difficult, but getting rid of the hum turned
out to be serious trouble. So much trouble that I'm
rebuilding the line stage with a separate power supply
unit. This line stage is so good I'm ready to go all the
way and I have even ordered a new power supply trafo to
get all the secondary tabs I want.
*Having success
with the silver interconnects, I thought it was time to
try out that silver foil for speaker cables I've had on
the shelf much too long. So, the foil was wrapped in
paper (painters' tape) and I ran bi-wiring to the DTQWT
having silver plated copper in teflon for the bass
drivers.
What a disappointment! Honky kind of midrange with poor
treble integration. Tried various musical sources - same
thing. Hmm.....Should it rather be a multistrand silver
cable, or is silver just bad for speaker cables?
Switching back to the silver plated copper in teflon
immediately brought back a proper soundstage with former
transparency and tonal balance. Weird!
Things like the above certainly need
repetition! So, next day I installed the bi-wiring system
again and it wasn't quite as bad as yesterday - late
evening - maybe I was tired, but something certainly
wasn't right. Midrange/treble integration still didn't
work. So I ran the DTQWT from the silver foil alone and
now things started to develop in the direction I had
expected. Silver does something to the midrange in
particular. It sounds less lush, less coloured, less
smeared. It sounds very cool and clean and you wonder
whether you would voice your speakers differently had
they been developed with silver wires, etc. How about a
DTQWT set-up with silver wires, Mundorf Silver/Gold caps,
Jantzen Audio Silver Coils, graphite resistors and - -
dream on. This would triple the cost of the kit. Anyway,
foil wires are trouble. Fragile, trouble when you need
cleaning around the speakers, low WAF, etc. What I really
had in mind was making a multistrand silver wire from
e.g. 12 x 0.4 mm silver wire = 1.5 mm^2. I only need 2.5
meters of speaker cable + 1.25 meter for internal cabling
in the DTQWTs, thus (4x12) x 3.75 meters = 180 meters of
wire = 235 grams silver = 1400 DKK (250 USD) from my
local supplier. Not too bad after all. Let's see.
15 February 2009
Yesterday was Saturday and with
the lady of the house gone shopping, it was time for some
serious kick-butt, rock'n roll. Front end was Garrard 401
+ LINN ITTOK LV II arm + Dyna XX2 mkII
cartridge/Transcendent RIAA with Mundorfs/TRAM w.o.t. line
stage (DiyHiFiSupply)/modded Audio Mirror 6AS7
mono-blocks/Rotel RB981 for bass drivers in DTQWT
speakers. The TRAM line stage has out-put transformers
(w.o.t. = with output transformers) and can easily driver
two power amps.
Needless to say this set-up can play at ear-splitting
levels without serious distortion. So, old Sgt. Pepper
and Band of Gypsys LPs were on the spinner - and not
least Dog Eat Dog/Joni Michell. I've had this recording
for more than 20 years and I never liked the sound, being
overly bright and harsh. I always thought this LP was
poorly recorded, mixed and cut, having the typical
Eighties hard-hitting, short reverb on drums. The XX2
told another story, revealing details I didn't know were
there.
Which makes me think of a
visitor I recently had, bringing in a 20,000 DKK (~3,500
US $) TentLab CD player to compare with my slightly
modded Shanling CD-T80 (I paid 650 US $ for this player
from Hong Kong). Playing a wide range of CDs, we really
weren't able to hear any difference at all. Now, my
visitor also brought a CD which I happen to have on vinyl
(Eva Cassidy) and this called for some A-B testing of
vinyl vs. CD. Visitor was pretty shocked from the
difference. Needless to say the CD sounded flat and
congested with poor dynamics and transparency compared to
what the XX2 cartridge could pick up from the vinyl
grooves. Now, CDs can be good and bad. I have a (very
few) excellent CDs where everything seems to have been
done right to get as much information through the media
as possible, but generally most of the CDs I have on my
shelves are poor. In Stereophile, Feb-09, you can read
about a demonstration at DIY Burning Amp Festival, where
" - Jan played back samples of the same song
released over a span of several decades. Each one sounded
worse, more compressed, than the last. It was so shocking
that it made people angry". No wonder!
Recent Months have brought
a range of new speaker constructions : SP44, CNO-mkII, CNO-T25, Maya (SEAS
CA18RNX/T25C003) and CNO-25 (CNO 2½-way),
and I guess I'll take a break from SEAS constructions
after this. I need to put together some plug'n play kits
to finance new projects. And I'll be cloning the TRAM
line stage and have started sourcing components. The
project I'm looking forward to the most is an open baffle
construction with the JA8008/TW034 drivers and some
15" at bottom. This OB should as close as possible
look like the old Wharfedale SFB. I just love
that design.
28 December 2008
Economic recession or not, people
are building speakers like crazy these dark winter
evenings and weekends - at least on the Northern
Hemisphere - and coming home from work, I find my mailbox
full. It takes an hour or so every evening and please
forgive my short replies. Usually the Christmas holidays
are very quiet with mails, so time for some writing and a
few experiments.
There are a lot of speakers in pipeline
the coming winter months: CNO mkII, CNO-T25 (T25C003
tweeter) and a CNO-25 (2½-way CNO). I have reworked my
test cabs for these constructions.
A replacement for the Peerless
HDS134 construction has been finished, this time
with HDS PBB
134 (830860) + DX25TG. The recently
launched PL14 construction is
a worthy alternative, but needs a 10-11 liter cab, where
the HDS will do with 7.5 liters. Some HDS164 Nomex
drivers (830875) are on the shelf too and might end up
with the Peerless HDS tweeter in a 2½-way construction
as a replacement of the old HDS164 (850438) construction.
For the DTQWT construction Eminence
DELTALITE 1520 II have been tested
and is the recommended bass driver option.
A Happy New Year to all diy'ers visiting
my website!
07 November 2008
Listening
to music
Do you have the same experience
as I that sometimes your hifi system sounds crap and
sometimes just sounds great? Nothing in the system has
been changed and yet there are good days and there are
bad days.
Whenever possible - and when I feel like - I often listen
to music on Saturday and Sunday mornings. It's weekend,
I've had a long night's sleep, I'm fresh and relaxed and
I'm fully open to the world and what I choose to let in.
I do this in particular when I have to evaluate a new
speaker system, evaluate new coupling caps in my amps, a
new cartridge or when I have new vinyls I want to fully
enjoy.
I'm tired after a normal working
day filled with mails that have to answered, meetings I
have to attend, talk with my colleagues, driving my car
and paying attention to heavy traffic, watching the news
and the Obama election, etc., etc. The everyday contains
an enormous amount of information that has to taken in
and/or taken care of - and after all this I'm really not
in the mood to be fully aware of subtle differences in
the performance of hifi components. Good or bad is
sometimes a matter of state of mind and not how the
system is performing.
I've sometimes had visitors who have spend 1½-2 hours in
a car and 5 minutes after leaving the car they sit in
front of my speakers and this is a far from ideal
"preparation" for having to do aural
evaluations. 1-1½ hour of car noise tires our mind and
ears and the general stress is bad for having to pay
utmost attention to sound.
Maybe I should name my next speaker "TGI" (Thank God It's
Friday). I think I will, and the 2½-way version
will be TGI-25. Anyway.....
Loudspeakers are the most troublesome
components in our system. We not only listen to our
speakers, we listen to our speakers and the
room, and not only the speakers in our room, but the way
the speakers are placed in our rooms.
Speakers rarely have #1 priority when it comes to room
decoration, which is sad because really they should have
unconditionally #1 priority. The "world's best
speakers" in the wrong room may be a total waste of
money.
Modern room construction and room decoration is often a
total disaster when it comes to acoustics. In particular
modern Scandinavian design with minimalistic decoration,
concrete walls, tile floors and hardly any fabrics in
terms of carpets and curtains. Bookshelves filled with
books aren't allowed either and stored away in smaller
"office" rooms. Clap your hands (once) in one
of these environments and you'll often hear severe
reverberation.
If you happen to have a listening
room of e.g. 20-30 square meters of reasonable
dimensions, square is often worst, take a day off and
move your system around including all your furniture. Try
every possible positioning of your speakers and hear what
happens. If possible try your system in a smaller room
and a bigger room too. Try the bedroom also! At least
here we may have some fabrics. Now, how does it all
sound? One room better than the other? One position
better than the other?
I'm pretty sure you'll all be surprised from how
enormously different your system performs. I've often
seen people spending minor fortunes on new speakers and
amps and what they should have done instead is maybe
buying a heavy 3 x 4 meter carpet or move a piece of
furniture into a corner of the room, etc. The number of
options is infinite when it comes to tweaking acoustics -
but give it thorough thought before spending 400 $ on a
new pair of silver interconnects that might do something
to that troublesome midrange. The money may be better
spent on a new 200 $ carpet in front of your speakers.
By chance I came about this
website: http://www.stereodan.com/stereo.htm
Take a look and enjoy the pics. Here's a guy who has had
a good time not only sourcing his components, but who
also has spend a lot of time positioning his gear and
treating his room. I have no idea - obviously - how this
all sounds, but I like what I see and I think it's an
example to follow with heavy carpets, bass trap in
corners, etc. It looks like somewhere in the UK. I don't
know the guy or where the website belongs.
19 September 2008
-
mails, magazines and other stuff .....
"Could I use 2 x SS
18W/16831G00 in replacement of the single bass driver in
the SP38/13 construction and
use the same crossover?".
Sorry, cannot... Still these are
the most common questions I have. I may have to re-write
the sorry-cannot file.... From the mails I have I can see
that the number of files found on my website has grown
considerably over the years and I've tried to organize
the intro page to make better overview. Hope it helps.
"Could you change the page
set-up in your files because I have an old
monitor and 800 x 600 pixel setup?" Now, that's a
new one! I have asked around and I can't find anyone
running this format anymore. I have a standard
laptop/14" screen and usually make my tables
1000-1100 pixel width. I use tables because it allows me
making the page layout I want (from my stone age Frontpage
version, I admit). I'm not particularly interested in
computers (- but I love what they can do) and usually
stick to my old software if it works well. There are
about 250 pages on my website and changing the format
would be an enormous task. So, "sorry, won't".
BTW: If you press "Ctrl" and roll your mouse
wheel, you can reduce/increase page size and view it all
to your liking. I don't know from which Windows version
this works.
The poor devil buying my TJL3Ws hadn't checked
with his spouse in advance and all hell broke loose when
the speakers were installed in their livingroom. Wood
finish didn't fit furniture veneer and to avoid sudden
divorce, the speakers were wrapped in white plastic
foil.... All that nice woodwork - for Heaven's sake!
Point is: Don't forget to check with your loved ones
before engaging in new speakers!
More WAF issues: I had a
mail from a guy showing some of my constructions to his
spouse to hear her opinion about possible designs. Now
that's the way to do it! Her response was: "All
these speakers look like coffins! Horrible!" She has
a point. Most floorstanders may look more or less like
upright coffins. We only need some flowers to bury our
addiction to music! The single construction she did like
was the Acapella. So, I asked my
wife the same question and she was in favour of the
Acapella too, comparing all the speakers she'd been
living with over the years. Hmm... I always liked these
cabs better than anything else I've made, but it will be
tough squeezing the DTQWT into an Acapella
design!
Thinking of coffins, these come in all
shapes and sizes and maybe this would be an options for
those engaging in speaker-building for the first time. As
can be seen above someone already got the idea. I have
seen speakers looking more terrible than these. Some
coffins come fairly cheap. Add braces and bitumen pads
and a pair of 12-15" bass drivers and I'm sure you
could impress you bodies - but I guess it's for
"singles only". To keep green-house gasses down
you can even buy coffins made from recycled materials
degrading without environmental damage. Fully RoHS
compliant!
(Pic in middle: calendar from an Italian coffin maker.
Nice coffin, BTW)
- anyway.....
Magazines:
Reading the latest Stereophile I couldn't help digging
into a review on the Fried Compact 7
loudspeaker (1795 $/pair) and I'll make this short:
Stereophile: "As shown in the Follow-Up elsewhere in
this publication, the FC7 significantly departs from
linear frequency response on axis. A huge suck-out spans
1-5 kHz, the deepest part of which (at 3.2 kHz) is about
-16 dB. There is also a suck-out from about 260 to 500
Hz, with a trough of -7dB. These doubtless account for
the hollow coloration I heard, and compare unfavorable
with Stereophile's 1990 measurements of Fried's Q4".
Fried's website: "Loudspeaker design and performance
has little to do with producing a flat response".
Stereophile/Follow-Up: "Some people prefer such a
response because it "nicefies" typically hot
modern recordings...."
 
I suggest reading the whole article at
Stereophile's website once published: http://www.stereophile.com/thefifthelement/
My point in bringing this here is that I think the reviewers are too
gentle on a seriously flawed product like this. Yes, it's a critical
article on a product being so badly constructed that the reviewer can
actually hear something is seriously wrong, hence ships the speakers to
Atkinson for measurements. First order filters, same polarity of
drivers...... Hmm...
An extensive test of
coupling capacitors has been performed on my 300B integrated amp and this is
a never-ending exercise. Mundorf silver/gold/PP and VCaps
are the winners here, but read for yourself.
And while we're at coupling caps: Should you have an
Rotel RB981 (my workshop power amp), try replacing the
two electrolytic caps at the input with some good film
caps. Very rewarding. I used two 1 uF/400V Hovlands.
Replace C601 and C602. These caps see 33k and can do with
1 uF caps without compromising bass extension.
Rotel RB981 with 1 uF Hovlands.
Download Service
Manual, 800KB
Last but not least: Some
bedtime reading on the state of hifi (Gordon Holt/1991
and Art Dudley/2004). Download here.
23 August 2008
Finally: The launch of the DTQWTs. It's
been a long, long journey and hifi - to me - has never
been more exiting. The DTQWTs are doing what I want my
speakers to do: A huge soundstage, a midrange delivering
the presence and detail I want without being harsh or
aggressive, deep bass delivering the punch and drama we
want from reproduced music and last but not least: High
sensitivity allowing low-wattage triode amps to be used.
With these speakers I can easily evaluate subtle
differences in the quality of components used in my
amplifiers. My Audio Mirror 6AS7 SET mono-blocks
and the 300B SET amp are already
revealing interesting - and different - ways of
amplifying source material and soon a Transcendent T16
OTL will be finished and tell if omitting
out-put transformers really is as important as Bruce Rosenblit says.
28 July 2008
The final DTQWT cabs are
shaping up and only needs the final lacquer before
finished. The DTQWTs pretty much do what I want my
speakers to do and I might just quit speaker building
here. My bank account to some extent reflects this as I
spend more money on vinyl and less on new drivers. That's
how it should be! Well, a few more amps are on my
wishlist and besides a diy 300B SET under construction, a
Transcendent T16 OTL has arrived.
The DTQWTs are sensitive
and they project a big, wide and transparent soundstage
and allow me to use all sorts of amplifiers, but I do
rush to say I do not recommend 2 wpc SET amps. No matter
what loudspeaker and amplifier producers may claim, there
are limits. I do recommend 6-8 watts minimum. Often we
see that 2 wpc amp producers may claim their products
suitable for minimum 90 dB speakers, but be cautious, it
very much depends. And speaker producers may claim their
90 dB speakers suitable for 5-10 watt amps. Again, be
cautious. I recently made a crossover for a large 3-way
speaker (ScanSpeak drivers) and I ran it from a 6 wpc SET
amp and it sounded great - but indeed not very loud. If
we run 2 wpc SET amps we need humongous horns with
extremely light-weight paper cone drivers to render a
true presentation of bass fundamentals.
Anyway, there will be more speaker
constructions in the future and more
2-way/6"+1" kits and some 3-way classic kits
from ScanSpeak 21W/8555-01 + mid + 8513 tweeter. I have a
range of mid drivers that look very promising from
simulation, i.e. simple 2nd order filters and flat
impedance curves. The D2010/8513 is special in this
context and seems just made for 3-ways with a relatively
high point of crossover between mid and tweeter. Modern
1" tweeters are often designed to extent the lower
end - to make two-ways - and some of the 3-way
simulations I have made got into serious trouble when
replacing the 8513/OWI with e.g. SEAS 27TFFC, SS 9500,
etc. These 1" dome tweeter often takes 3rd or 4th
order filter to perform from e.g. 3.5 kHz in a 3-way
set-up. The EKTA might do well with the 8513 tweeter from
a simple 2nd order filter at 3.8 kHz - but I'm afraid
people wouldn't believe it.
The summer sale quickly
ran out of 2-way kits and I need a break before launching
more. Selling a kit requires quite some hours of actually
making the kit with presentations, etc., and often takes
10-20 mails before it's actually sold, not to forget
packing the kit to ensure safe transport. But it's also
fun hearing from people all over the globe and exchanging
views on speakers building.
One of my summer holidays has been
spent reading reviews - speaker reviews - and gosh, are
reviewers and manufacturers one big family! I'm amazed by
how reviewers manage to write 3-4 pages on a new speaker
that is slightly different from the old model. We are
told it's a significant improved product, yet in no way
does it diminish the qualities of the old product. So,
we're all happy! A few times I may actually know first
hand the new drivers - don't ask how - and know the
changes were made to cut production costs and increase
profit. I wouldn't never blame manufacturers for doing
so, but the way reviewers are able to handle this is a
matter of linguistic artistry. Bravo!
What's more serious is the factual errors often found. A
six inch driver that is really a five inch driver and a
paper cone that is really a polyprop cone, etc., etc. I
sometimes wonder if the reviewer really had the speaker
in his room. I guess he had, but should leave
technicalities to someone qualified.
Buying on eBay has been
low for the past months, but a single Wharfedale Super
8 FS/AL was found - and bought. And it's one of
the better drivers from the Fifties. Much better than the
terrible Super 8/RS/DD. As expected,
not much of the foam surround had survived transport but
I managed to find some fine felt material and have made a
new surround. What I don't get from these Wharfedale
drivers of the Fifties and Sixties is the acoustically
transparent outer surrounds. Why? Even some of the later
fabric surrounds were acoustically transparent. It causes
serious trouble in the midrange. It doesn't fit with the
response graphs found in Briggs' book. Any ideas?
I also found - and bought - a Wharfedale "North
England M8", same basket as the Super 8 FS/AL,
square alnico magnet, 15 ohms cobber wire voice coil,
fabric spider (!) and - former - foam surround. I wonder
what these were for - probably diy units. This is
actually a NOS driver - never used and including original
box. Cone in perfect shape. It will have a new felt
surround like the Super 8 FS/AL.
17 May 2008
Launching a sale takes a deep,
deep breath! Space and finance is the reason
behind this and I know it takes tons of mails back and
forth before diy-people decide to buy anything. But here
we go! Take a look at the '08
Summer Sale' if you might be thinking about
the following items: Acapella NEXT, TJL3W, Compact Studio
Monitor Kit, JBL L100 matched drivers + crossover KIT,
ARC SP16L preamp, TubeBox phono stage, Rega
RB300/Incognito tonearm and W11XT speakers.
Please do not feel disapointed with me from selling the
e.g. Acapella NEXT and TJL3W. If space was unlimited I'd
keep these speakers forever. The numerous hours that went
into designing and building them is something I simply
have to repress. The recent 150 liter project has made
this step absolutely necessary.
7 May, 2008
It's springtime and really not a
time for doing loudspeakers, but you can always
gather components for the next project while digging the
vegetable garden and mowing the lawn. And so I do - like
seen on the photos below. 10" bass drivers, wax
coils, super caps, cables in teflon wrap, low-ohmic
C-coils, new cable plugs, gold plated soldering tags,
etc. All meant for the DTQWT project, i.e.
Double-Tapered-Quarter-Wave-Tube.
The DTQWT is the JA8008/TW034 kit
with two 10" drivers on the rear panel loading a
common center horn together with the front driver. No big
deal really, but finding the right bass drivers and the
right dimensions of the horn has taken time. Some 5
different 10" drivers have been tested and two
candidates seem to do the job well. One is Beyma 10LW30N,
rather expensive but with excellent build quality. The
other is a 10" Pioneer driver derived from the US.
This one is cheap and does a great job too - at a
fraction of the cost of the Beyma drivers.
With two 10" drivers the total (bass) membrane area
of one speaker now exceeds one single 15" driver and
it can be heard - and felt. Tight, deep bass.....
The DTQWT has the same front panel dimensions as the TQWT
but is now 50 cm deep. WAF hasn't gone down too much from
this latest version, fortunately...
My system has been through a
lot of up-grades lately and this has urged me to use the
very best I can afford for the DTQWT. In addition to the
components seen above I'm doing homemade silver foil
speaker cables and graphite resistors for the crossover.
I'm not sure all these measures will contribute equally
to the good sonics, but for the benefit of the doubt -
and to gain experience.
Gathering components also includes
bits and pieces for a 8 wpc 300B SET amp. I need
a really low-wattage amp for reference with the MAE now back in
Norway. The 300B amp is based on the Oliver design shown here.
20 March, 2008
I've bought a new phono cartridge!
I never invested heavily in these things and I was pretty
happy with my Dynavector 10x5 until a wire from one of
the coils broke and these tiny wires are way too thin for
repair (I tried). So, a deep pocket dive and a Dyna
DV20X was in place. 400 £ for a cartridge was
serious money I thought, but it provided one of these
rare occasions where you - once more - have to go through
a lot of your vinyl collection to hear what you've missed
over the years. Self-pity is a really bad thing, but it
came close and it kept me wondering what I would get for
800 £ or maybe even 1600 £. Better start saving for
that next step.
The DV20X is the high-output version because it works
wonder with Bruce
Rozenblit's Transcendent RIAA. I recently
installed the alu/silver/teflon caps I got from Mike in
Moscow. The RIAA feeds a Transcendent
Grounded Grid preamp if not an Audio Research
Corp. SP16L line stage. Bruce's amps provide true
high-end amplification at modest price and there's no
mushy valve sound if that's what you want. Solid state
speed combined with all the transparency valves can
provide, which is really the wrong thing to say because
valves aren't slow by any means, they just have this sad
image from old mushy valve amps driving inefficient
speakers.
Should you want to try out the GG preamp, add the
shorting circuit and the 50 k attenuator to your buying
list. The standard pot supplied with the kit is crap and
the ELMA attenuator is an excellent layout for listening
at low levels. The GG preamp is merciless clean, neutral
and transparent. The SP16L may have a slightly warmer
sound compared to the grounded grid but a tad less
transparency. I currently use Superior Z-caps in the GG
but I have some new prototype gold/silver caps from
Jantzen Audio and the GG is the place to test these. 2 x
1 uF is what's needed, leaving excellent opportunity for
experimentation. I also have to try the brown 1 uF PIO
cabs from Mike.
Piano is a particular difficult instrument to reproduce
faithfully and I never really liked the sound from the
Steinway piano on Keith Jarrett's The Köln Concert
until I had this Dynavector DV20X. I always thought it
sounded a little bit too harsh and aggressive. I favour
the sound from e.g. Oscar Peterson's Bösendorfer piano,
having a sweeter and more mellow tone. But the DV20X dig
out the vibrant and forward sound of the Steinway in a
very persuasive manner.
The ATR25 was
finished early March - took a long time to get
the cabs finished - and these are "disturbing"
speakers. Disturbing because they do a lot of things
better than any other speaker I have. Still don't beat my
JA8008/TW034 - a matter of taste and WAF - but at half
the size - and twice the cost - they take midrange
clarity and treble quality to new levels. No domes can do
what these planars can do, that's for sure. My 20 wpc SET
mono blocks have no trouble driving these transmission
lines and I'm having good times in front of these
speakers. Despite high level of transparency, they handle
all musical genres equally gracefully. They don't make
poor recordings sound worse. Low distortion is the key
word.
Right now the JBL L100 Recreation
is on the workshop bench. Cabs are finished and I need to
add damping, install crossovers and drivers. I think I've
spoiled the L100 kit as much as possible and I'm looking
forward to hear if it all makes a significant improvement
compared to the originals. I think it will. The original
box is rather resonant and having the 12" bass
driver handling most of the midrange, there just gotta be
serious improvement gained from a well damped and braced
cabinet.
On my way home from work today
I picked up some 5 square metres of 19 mm DMF (pre-cut to
some extent) for my double TQWT, the next JA8008/TW034
system. Have collected 10" bass drivers over the
last half year and I'm expecting to have some 5 pairs for
test. Two pairs of Beyma drivers, two pairs of SEAS
drivers and I'm waiting for the last pair of 10"
drivers from the US. You can find the principal
"DTQWT" design here and here: Two conical
horns feeding a common center horn mouth.
The High-End Kit for Beginners
is ready for sale.
Orders here at: contact@jantzen-audio.com.
Article here: http://www.troelsgravesen.dk/AT-SW.htm
The JA8008/TW034 is ready for
sale.
Build a high-efficiency 2-way system for high quality
low-wattage valve or ss amps.
Orders here at: contact@jantzen-audio.com.
12 January 2008
The
Acapella
NEXTs are up and running: This
project started like: "Well, I have the cabs and
only need a bass driver" and turned out to one of
the most rewarding projects I've made. You never can
tell.
There's
a long list of projects planned for 2008. After
the Acapella NEXT, the ATR 2½-way is next. View
ATR-2-way here. Initial test set-up will be a
bass-reflex design and initial listening test from a
quick simulated crossover is promising. The final cabs
will probably be a classic transmission line with the
same front panel dimensions, allowing the crossover to be
the same for both versions.
When
the ATR-2½-way is finished, the JA8008 55-litre
bass-reflex is scheduled. The project has been on hold
for some time as initial tests in a classic 36 x 80 x 28
cm (W x H x D) cabinet didn't sound right. The crossover
was easy, measurements were good, but the sound was just
too forward. Too much midrange despite an overall flat
response. My main suspicion is the width of the front
panel and a more narrow design will be tried. Actually
similar to what can be seen on the sketch shown at the JA8008
page.
The JA8008 3-way, double TQWT, is certainly on the agenda
this year. I have some old SEAS CA25FEY drivers for a
start for the rear mounted bass driver.
Next
project is something I'm really looking forward
to do: A "W26-Classic" 3-way
from SEAS W26FX002 + M15CH002 + T29CF001. Possibly the
middriver is going on top in a separate semi-open
cabinet. Having the mid on top is seen before in older
KEF & B&W speakers. However, my initial
inspiration came from the Spendor SP100 and Naim DBL.
We'll see.
The W26FX002 is a very capable 2" voice coil bass
driver with lots of punch and a better frequency response
than suggested in the SEAS data file. It has a smooth
roll-off and one of the few drivers you can stand
listening to full-range. Furthermore the claimed 89-90 dB
sensitivity seems to come true and this should allow an
overall 90 dB system sensitivity. The M15CH002 is not an
easy driver in terms of crossover construction but it can
be done and I'm looking forward to hearing what this
low-rear-reflection design can accomplish.
The "W26-Classic" cabs
will also allow a test set-up of my JBL L100
drivers. Modelling the 123A bass driver in a 65 litre cab
looks promising.
Did I say 2008? I also
look at my Spendor BC1 speakers from time to time and I
have 22 mm plywood sheets on the shelf for new front
panels... and I've had a pair of "vintage" SEAS
EXCEL W21EX001 drivers for a reasonable price. These
drivers have a hard paper cone and performs exceptionally
well although sensitivity is some 3-4 dB lower than
promised from the old SEAS data. An "EXCEL
VINTAGE" from W21EX001/W11CY001/tweeter could be
interesting.
Well, one thing at a time. Fortunately this is a hobby
with no boss yelling deadlines and milestones.
Speaker Talk 9 December 2007
SEAS has got
a new website and it's certainly better than
before. And they are about to launch a new
"alnico-whizzer" driver - with rubber
surround...Hmm... Have they heard the cry from the
SET people right?
Anyway: I've had a pair of the new 27TBCD-GB-DXT some
weeks now and this is certainly the tweeter with the most
even power response I've ever had. All the way up to 20
kHz. Very well made indeed.
While the Norwegians seem
fit for fight, I'm wondering how things are in Videbaek
town, not too distant from where I live. Apparently
people are fleeing the castle of Vifa/ScanSpeak and have
started new companies, e.g. SB Acoustics and GAMUT, based on former
dst employees. I'm sorry to say that
whenever you guys "over there" take over
smaller companies "over here", things seem to
rapidly deteriorate - from our perspective. RCF, Audax
and now Vifa/Peerless/ScanSpeak are examples. I'm
wondering if the Tymphany air-pump can compensate for the
departure of some key figures in the former dst
organisation. This is - to my eyes - the only radical new
product from the Tymphany company for a long time.
One thing is capitalising well known brand names, but who
will make the next generation of drivers after the e.g.
sliced paper range? At present we see Usher speakers
fitted with drivers similar to what ScanSpeak developed 2
decades ago. Is Usher sliced paper the next to come? The
new range of drivers from SBAcoustics look interesting,
but purely based on specs, they seem to face tough
competition from a lot of other brands. The initial
announcements from SBAcoustics leaves no doubt:
"Hey, we're the former ScanSpeak people!"
Soon we may have only AudioTechnology and HIQUPHON left
here in Denmark. The Peerless factory has long been
closed and maybe there isn't any future for driver
production in Denmark, unless you develop specialty,
high-priced products. Driver manufacture is not
necessarily rocket science and soon the Chinese may be
producing the former DK brands as is the case with a lot
of former UK based brands, like QUAD, Mission,
Wharfedale, etc.
This Month's Speaker Talk
was meant to deal with a few reflections on how
differently we perceive sound. Not a new topic, but I
still wonder sometimes how people claim aural nirvana
from speakers I dislike - and know first hand - like the
vintage Philips 9710. I had a mail from a studio
engineer, seriously suggesting this driver as a great
tool for monitoring. I don't get it.
Anyway, from visiting numerous websites I came across
these wise words from Wilke/Germany, and this very much
tells what I had in mind:
"I have found myself
100% captured by listening to 12 x 17 cm full range
drivers mounted in cardboard boxes with an open back. I
have also found myself 100% involved by listening to 40
cm coaxial drivers. Every speaker has something to say!
The beauty of the sound of some small driver may weigh up
the power of some big driver. On the other hand, the
sheer power and authority of the big driver may please me
more than the delicate sound of the small ones. It
depends on my mood and on the sort of musical material. I
have had lengthy discussions with a former Klangfilm
speaker engineer and we have both agreed that the whole
matter depends very much on proportion and on harmonic
and well balanced tonality. If you listen to a 20 cm full
range driver you will obviously not hear the authentic
impact of a full scale big orchestra. But – provided
it is a “good” driver – you will hear the
orchestra as an entire phenomenon. On a smaller scale!"
Read
the full article here: http://www.german-vintage-loudspeakers.com/navid.458/an-approach-to-sound.htm
In line with these words,
I recommend reading an article by Art Dudley
(Stereophile, Nov-07, page 41) on a speaker system from Aurum Acoustics:
"Bear in mind that even the hard-core
single-ended-triode movement wasn't conceived as just a
new branch of high-end audio: It was intended as a whole
new tree, by hobbyists who considered the old tree to be
very, very sick. To the SET pioneers, audio had gone from
being an interesting way of enjoying recorded music to a
turgid and fetishistic exercise in irrelevance in which
wealthy men with too much time on their hands try to
outdo each other in identifying arcane sound effects in a
handful of guru-approved recordings.
Also remember that the high-end audio establishment
didn't take long to dismiss the SET guys as a bunch of
self-conscious hipsters less concerned with fidelity than
with the coolness factor: gracelessly aging punk wannabes
whose willingness to live with grossly colored , narrow
range sound reproduction is rivalled only by their
disdain for any model of amplifier or speaker that might
be owned by more than two other people.
The fact is, there's an archetypal high-end audio sound
and an archetypal SET sound. At its best, high-end audio
sound is impressive open and clear, with deep bass,
shimmering highs, and a flair for thrilling spatial
effects: At it's worst, it's lifeless , boring,
constricted, undramatic, uninvolving, and incapable of
any suggestion of flow in the music.
At its best, SET sound has the kind of punch and
drama that can startle you out of your pants - plus real
musical drive, momemtum, presence, and tone; at
its worst, it has no bass, no treble, and a level of
coloration and sheer fuzz that could drive you out of
your house after a few songs".
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