Answers to some of the most common questions I have
LACQUER and OIL GLUING BITUMEN PADS AND FELT REMOVING STUCK DRIVERS MDF and BALTIC BIRCH
TERMINAL BLOCKS/CONNECTORS SOLDERING FEET FOR CABINETS SEALING WIRE HOLES MAKING REBATES
CABINET DAMPING, GO TO PAGE WIRING, GO TO PAGE PORT DIMENSIONS CHAMFERING DRIVER HOLES
SPEAKER PLACEMENT TABS AND SLOTS FOR BRACES MY DAMPING PANELS

Download data sheet
here.
For crossover boards, silicone glue may
work great, but this is even better and settles faster. Superfix from
Casco
or
Bostic.
Except for Scandinavia, I have no idea about the
availability of this compound in other countries. It's expensive, around 20-25 US $ for 300 mls, but worth
it.
It's a non-toxic, doesn't smell, tough to get off your
fingers, doesn't take any solvents except alcohol, flexible and easy to
cut when hardened (remove crossover components because you've got new
ideas...).

Solder tag strips helps you keeping good
order and overview, in particular when several components, wires have to
be connected to the same spot. I always make a ground loop from a piece
of solid copper wire like here with three components attached + several
wires when connecting the drivers. Not easy to do "in the air".


Superfix is also available in 40 mm tubes. At least in Scandinavia.
Hopefully soon available from Jantzen Audio to be purchased with the
speaker kit.

If you cannot find Superfix, use any kind of
silicone glue, no problem at all.
Foil coils can be heavy! Use a dowel and a
gluing ring
of Superfix or silicone glue.
You can also use brass or stainless steel screws to the wooden center plug.


From Erik, Netherlands:
Casco and Bostik are hard to get here
(Netherlands), but now I know what to use. Similar construction glues
are here available from Bison or Pattex and they are available in every
building market. Best regards,
Erik
From MB, Spain:
I've asked about "MS technology" to a friend that works in a
chemical company and these kinds of glue are very often used in Car
Repairing due its properties. He told me that another brand that have
this technology is "Teroson", and some of the glues are: teroson ms 9120
sf wh cr310ml, teroson ms939 wh fc570ml and teroson ms 9220 bk cr 310ml
epig.

Click image to view large (and upright)
http://www.ceys.cz/mstech/mstech2.htm
Finally, I’ve done more research about the “Ceys” glue and is a Spanish
product. It’s made in Bigues i Riells (Barcelona). Ceys is a company
that is part of “AC Marca Group”. It’s website is:
http://www.grupoacmarca.com/en
I’ve talked with them (so kind!) and have explained me that they have
subsidiaries in America (Mexico and Chile) and Europe (Portugal, Czech
Republic, Slovakia, Romania and Hungary), so maybe it’s easy to find
this glue in those countries.
The Tereson glue is Henkel product:

From Cole/US, I had these recommendations:
Glue for crossover
boards and felt sheets:
We would use A Hot Glue Gun in the U.S. Or the German Henkel Teroson
product MS 930 available from the US Mercedes-Benz dealership in a tube
for ~$18.00 USD. Part number: 005-989-61-71
Wood Glue for Cabinets
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I use nothing but standard PVA glue
for cabinets. No nails or screws. I guess this is more or less the same all over the world.
"Wood
Glue" is usually PVA based adhesive.
You can use screws, but take care with particularly MDF. Pre-drilling
is necessary not to split the MDF.
US:
Titebond PVA Glue - Titebond II,
http://www.titebond.com/Libraries/LiteraturePDFs/FF683_GlueGuideTB.sflb.ashx
Available on Amazon and Zoro.com for a
good price. The Titebond III has a higher strength and longer setup time
which is an advantage and the price is almost the same as Titebond II.
Also, it is waterproof.

Glue for Bitumen Pads
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Although bitumen pads may be self-adhesive, they
need to be glued to the panels. Years ago I relied on the sticky sheets,
only to find they would start peeling off a year or two later.
Thus, I
recommend using the kind of glue we use for e.g. floor vinyl
tiles/sheets. This is some sticky, gooey stuff and use disposable gloves
when using it. Add a thick layer to the bitumen pad placed on internal
panels. Make sure it's got contact on the entire surface. This "floor tac"
to some degree stays elastic, which adds to the damping properties of
the bitumen pad.
US:
This is the best choice from the company DAP Weldwood,
https://www.amazon.com/00141-Multi-Purpose-Floor-Adhesive-1-Quart/dp/B0006MXRXO
Available on Amazon and Zoro.com for a
good price.

Setting up speakers
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It goes without saying that setting up speakers correctly is pivotal
for getting the best from your kit. There are loads of sites
on the web to help you out, and here's one:
http://www.cardas.com/room_setup_main.php
Remember the room is half the system! It doesn't help buying the most
expensive gear if your room is less than reasonably well acoustically. A
pair of speakers can sound wonderful in one place and dreadful in
another.


This one fits my room the best. The numbers mean of if you have the
speakers 1 meter from the front wall (the wall behind the speakers) you
have an optimal distance of 1.62 meters to the end walls of the room. If
you have the speakers 0.8 meter from the front wall, then 0.8 x 1.62 =
1.3 meters to the end wall.
If you have the speakers on the end wall, the distances are the same,
only visa versa, 1 meter to side walls and 1.6 meters to front wall. I'm
sure not everyone can fulfill these guidelines.
Now, the above only goes for two dimensions, but the height of the
speaker is another key player.
Download excel file
here
to find your placement from cells B25-26-27.
MDF AND BALTIC
BIRCH
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Above my three
preferred materials for cabinet construction, MDF standard, MDF black
and Baltic birch. I rarely use anything but 15-16 and 19-20.5 mm
thickness.
The Baltic birch I use is usually 20.5 mm but it can vary a
little. Sometimes I use 15 mm for bracing. Baltic birch may consist of
15 layers for a 20 mm sheet and the density is some 700 kg/m^3. It comes
i various qualities, e.g. B/BB, which is what I use:

MDF is excellent due to homogeneity and in particular the black MDF,
which I often use for front panels. Black MDF is really HDF,
high-density fiberboard, weighing some 0.84 g/cm^3 compared to 0.64
g/cm^3 for the common brown MDF, although it depends on MDF thickness.
Thick MDF sheets often have a rather soft center as producers may cut
production cost by reducing glue content. This black MDF has an almost
ceramic feel to it and comes at approx. twice the cost of standard MDF.
For most cabinets I use Baltic birch as it gives me the final finish at
once without going through the trouble of veneering. See lacquer
treatment below.
MAKING A
DRIVER HOLE BIGGER
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Driver basket comes with tolerances and I always
advise not to route for drivers before you have them at hand and can
measure the diameter exactly. My new baby, the
JA8008-HMQ,
came in a basket 0.3 mm wider than the old one. This is within
tolerances, but my QUATTRO cabs had a very tight match to the driver and
I could not squeeze the new driver into the rebate and had to increase
radius by 0.2 mm.
I have a whole box of inserts like seen above and I use them whenever a
new driver just doesn't fit in. In most cases I have to countersink the
screws not having the router bit destroyed by the screw heads.
TERMINAL BLOCKS/CONNECTORS
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To make good connection between cabinets(e.g
Jenzen speakers) we need connectors that can be tightened hard and
represent little metal mass at the same time. I'll claim these
connectors are better and cheaper than anything else you can find and
much better than any banana plug in some dubious socket.
They can be used for connecting speaker cabinets and if we want e.g. tweeter
attenuation easily assessable.
I have only found one supplier of these terminal blocks and he's in
Taiwan, but easily assessable via eBay:
http://www.ebay.co.uk/itm/5pc-PCB-Terminal-Block-GGB-40-08-A04P-4P-20A-300V-pitch-10mm-Wire-Soldering-/141207380595?pt=LH_DefaultDomain_0&hash=item20e09da273
The placement on eBay may change from time to time, if so, start
here:
http://stores.ebay.co.uk/wondercobuy79?_trksid=p2047675.l2563 - and
use search function for "terminal block" and scroll down.
You need 7 mm forks to go with these. DO NOT crimp wires! Remove insulation and solder.
BTW: These connectors are used by Vandersteen due to low metal mass -
and cost obviously.
Turns out Parts Express have them too:
http://www.parts-express.com/nte-25-b100-04-4-pole-solder-lug-type-barrier-terminal-strip--090-856
item 090-856.


Available with two connectors too.


Use Teflon insulated wire and heat thoroughly!
SOLDERING
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I have the question on soldering from time to time and here's what I
use. The Weller WSD81/WSP80 is expensive and much less than this can be
used for making perfect soldering. The soldering iron, WSP80, is 24V/80
watt and I mostly use a B tip for crossovers.
The solder I use is 0.7 mm 60/40 (Sn/Pb). This is not RoHS compliant,
but works much better than 99.7/0.3 (Sn/Cu), which is a terrible. I
never use silver solder.

Take care when soldering tweeter terminals. They are usually fragile.
Add solder to the wire and next to the terminal, but only for a second
or so. Hold the wire to the terminal and heat as little and short as
possible to make the two merge.
Gluing
bitumen pads and felt damping
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Floor tack is excellent for gluing felt.

click images to view large
Although bitumen pads may be self-adhesive, they
need to be glued to the panels. Years ago I relied on the sticky sheets,
only to find they would start peeling off a year or two later.
Thus, I
recommend using the kind of glue we use for e.g. floor vinyl
tiles/sheets. This is some sticky, gooey stuff and use disposable gloves
when using it. Add a thick layer to the bitumen pad placed on internal
panels. Make sure it's got contact on the entire surface. This "floor tac"
to some degree stays elastic, which adds to the damping properties of
the bitumen pad.

Bitumen pads usually come with a very thin foil. Peel it off if you have
to attach felt sheets afterwards.
Screws for
mounting drivers
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Click images to
view large. All screws from PartsExpress, US. Left:
081-425, #8x1. Middle:
081-422, #8x3/4. Right:
081-435, 6x3/4
All screws also available from
Jantzen Audio.
First of all: Threaded inserts and T-nuts: I
hate them! They do nothing good a standard wood screw cannot do. Threaded inserts are a pain to mount correctly and most
often there is not enough space to mount them properly due to chamfering
of driver hole. T-Nuts: Even worse! I had numerous diy-speakers in
for crossover work and the first thing that happens when you have to
un-mount a T-nut mounted driver is that one of the T-nuts gets loose and
starts rotating with too little of the screw exposed for cutting. And
mostly you cannot get to the inside of the cabinet to get hold of the
loose T-nut. Next: 6-8 good wood screws will fasten any driver more
than needed. If I know I have to remove the driver several times I start
drilling a 2.5 mm hole (in MDF) and fill the hole with synthetic
lacquer. Leave it overnight and you'll have a plasticised hole even
stronger. For solid wood this is not needed. In all cases with the above
shown screws, drill a 2.5 mm hole before mounting the driver.
I've
searched Europe for similar screws but can't find any. These are black
"hardened" screws, acid treated or something. Don't buy painted screws
as the paint will start peeling off.
I use the #8 x 1 for bass
drivers (even up to 15 inch), #8 x 3/4 for middrivers and #6 x 3/4 for
tweeters. #8 x 1 means 8 mm diameter head and 1 inch long. You US guys
have some trouble with metrics it seems! Millimeter for diameter and
inches for length. Like the Britts using Celcius when it's really cold
and Fahrenheit when it's really hot.
Do not think a speaker driver is a something meant to go
into orbit. Fasten screws properly but don't overdo. I sold a
12" JBL driver to a guy complaining the voice coil was scraping. It
turned out he'd fastened the driver so tight with T-nuts that he had
bent the driver gasket!
At some diy forum I read a posting from a guy claiming
significantly improved sound from replacing his iron screws with brass
screws. I suggest some proper therapy too!
REMOVING STUCK DRIVERS
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Sometimes it can be a real pain removing a driver
from its cabinet, maybe due to lacquer or tight routing and the simple
solution is making treads in one the mounting holes in the basket. For
8" drivers usually 6 mm threads work. For 4-5" drivers maybe 5 mm.
Measure hole diameter and use the the nearest size. Insert a screw and
lift the driver with a plier resting on a piece of wood. Simple as that.

My
Router guide
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Click
images to view large
Router:
Dewalt DW621
The great thing about the Dewalt DW621 is that
is has rotating suction at the top!


The guide can be bought from Jantzen Audio and
also on
eBay (Germany):
http://stores.ebay.de/weyher-holztechnik
As can be seen from the
pics, the guide was modified as the pin (4 mm screw) is
too large and un-handy for precision routing. I shortened
the alu bar and inserted a 2 mm hard steel pin (concrete
nail). The large handle on top was also omitted as this
prevents routing very small holes.

For chamfering driver holes I use this. Read
page on the
importance of chamfering driver holes.

The router bits I use the most, 6, 10 and 20
mm.
Routing for driver rebate

I've had this question also: How to measure
the cutting radius on the router guide.
I hope the images are self-explanatory.
I always start making the rebate a little too small, then increase
diameter by 0.1-0.2 mm at a time.
AND - I ALWAYS DO A TEST ROUTING BEFORE DOING THE FINAL BAFFLE.
TABS
AND SLOTS FOR BRACES
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Had the question on how to make tabs and slots for the braces.
Hope images are self explanatory.

Faceting panels and fillets
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I hope the images
above and below are self-explanatory in how panels and fillets can be
faceted. Obviously the same thing can be done with a planer and
sandpaper but I admit you'll be less exhausted using a table saw.
Faceting a whole front panel takes the rig seen on photos. I made this
from some MDF leftovers. Faceting a fillet (final image) is easier as
you don't need more than the standard table saw rip fence. Make sure you
count ten fingers when you're done as you can't use the blade cover
guard. Always make test cuts before doing your final panels to make sure
all adjustments are done.
For small panels I sometimes use a rig attached to the sliding table.

Here's a tricky faceting done on the table saw.
Above the easy parts, the tricky parts I do by hand, view
SP44 front panel.
Here are the photos:

Faceting the front
panels. Use 1) chisel, 2) planer and 3) sandpaper. Takes a few minutes
from MDF.

MAKING REBATES

Cutting 45 deg for cabinets
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Had the question on how to make these sharp 45 deg cuts: Cut from the
left side of the blade. Usually tilts towards your right. Made a guide for the sliding table held in place by a clamp.

How to make your DIY table saw:
http://www.youtube.com/watch?v=FR94aheUe60
http://www.youtube.com/watch?v=fhfMQszFgS0
-
this one more sophisticated. Lots of videos on youtube! http://www.youtube.com/results?search_query=diy%20table%20saw&sm=3
The DTQWT front inner panel - may be useful in other places.

I've
had the question many times on how to chamfer the inner front panel of
the DTQWT cabinet. Simply place a sliding board on the front, adjust
the router bit to the height of the side panels and move the router
slowly from side to side.
CHAMFERING DRIVER HOLES
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The amount of energy coming from the rear of the driver is
exactly the same as coming from the front!
Make sure your drivers can breathe and deliver their energy to the
absorption material inside the cabinet and not experience acoustic
resistance and diffraction from deep straight holes.

Read
here

This is how I usually make driver holes.


If you have double front panels due to stepped panels, do like this.
Normally I don not chamfer drivers holes once we're into 8" drivers, at
least not for 20 mm panels. For 40 mm panels I would.
For 10-15 inch drivers no chamfering is needed.
Lacquer, paint
and oil
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For finishing the Baltic birch panels I use synthetic lacquer applied
with a roller. Semi-gloss 25-50 is used. Usually two coatings will
do with in between sanding (grade 180). I sometimes add the 1st
coat before the final cutting. This reduce edge ripping as the outer
veneer of Baltic birch is rather thin, unfortunately.
For cutting small object from Baltic birch without ripping edges I use a
4-6 mm MDF panel below the Baltic birch. Sometimes painters tape is
enough to avoid edge ripping.
PAINT

The quick and cheap finish: Water based paint applied with a roller.
Gloss 20 used here.
OIL

I mostly use mineral oil for the black MDF front panels. This product is
for hardwood kitchen tables.
It takes two coatings. For every application excessive oil must be wiped
off before drying.
Flanging straight vents
made from ABS plastic:
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The pics below are
hopefully self-explanatory.
A number of vents are made from ABS plastic and usually
requires to be cut to target length.
The outlet of the tube is already flared and after
cutting to required length, the inner opening may
be given the same treatment simply by heating the end of
the tube with heating gun.
I run my B&D heating gun at highest temperature and
hold it 5-7 cm from the end of the tube while
slowly rotating the tube. When the tube opening starts
softening I push it towards the bottle shoulders
and continue to rotate while pushing. When done I hold
the flared end towards a piece of MDF while
cooling and you may add cold water to cool faster.

Solder tag
strips:
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This is a question I've had many times: Where do
you get the solder tag strips
used for the crossovers?

The above come from RS-Components and you have to order from
a shop dealing with electronics.
rswww.com homepage
Item 433-775, approx. 2-3 US$/ea. Minimum is 10
pcs.

I introduced the RS-Components solder tag
strips to Jantzen Audio and they were able to source the gold plated
version seen above. These are now standard with all crossover/speaker
kits from Jantzen Audio.
DAMPING MATERIALS AND CABINET DAMPING, LOOK
HERE
GASKETS
FOR MOUNTING DRIVERS
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I never use gaskets for mounting
drivers, but if for some reason your driver rebates aren't nice and
smooth, you may need to add a gasket between the frame and cabinet. Cut
suitable circles from thin polyurethane foam, the kind of thing we get
every time we buy a new electronic gadget, glassware, or whatever we buy
these days, even fruit from China, I've seen.
FEET FOR CABINETS
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I hate spikes and I honestly don't think they do
much good, if any.
I use cheap furniture feet bought at the local Bauhaus.
They have a 10 mm thread and I buy some M10 bolts and fasten them with
Araldite.
Preparing
for the adjustable feet. The bolt is fastened with epoxy glue. Fill a
syringe with epoxy and inject around nut.
I use WEST/SYSTEM 104 epoxy, mix 5+1, rather thin when mixed. Use large,
short and blunt needle to inject.
SEALING WIRE HOLES
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I've had this question several times lately: How
do you keep e.g. small midrange cabinets tight when you have to drill a
hole for the wires? Easy, drill an e.g. 8 mm holes, pull the wires and
fill the hole with e.g. silicone glue.
PORT DIMENSIONS
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To cut a long story short, effective port dimensions of a slightly
tapered port is X and Z as seen above.
I read somewhere cotton towels were excellent for
making damping panels, so I bought twelve 70 x 140 cm heavy towels at
the local JYSK. For the frame I use standard 37 x 57 mm lath wood and
cut them on my table saw to the profile seen on the drawing.
Stretching the towels I found them covering some 740 x 1460 mm, thus my
inner frame were made to make these dimensions. Three layers on each
side were attached with staples.
I placed three of these in my workshop and does it work? You bet it
does.
Obviously they can be covered with some nice fabric if meant for living
room.



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