Speaker Talk 2014-18

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 6th December 2018

Now public here 

 24th November 2018


In pipeline and to be launched before the end of this year are two construction featuring some unusual crossovers. The inherent smooth response of ScanSpeak Ellipticor drivers allows 1st order crossovers to be used, in fact the complete crossover is only three coils and two resistors for this 2½-way with added 32W sub. No capacitors needed. The 21WE and 18WE drivers also run without any high-pass filter and the overall simplicity pays off in unprecedented transparency and coherent soundstage. One of the few speakers I've made that made me run through a lot of recordings to hear what I have been missing so far.

Next in line is potent 3-way from SBAcoustic drivers, here a 9½ inch bass driver, 4½ inch midrange and the magnificent TW29RN dome. A combination of 1st and 2nd order filters deliver a smooth and transparent soundstage with a deep bass from the 9½ inch Satori driver. Click link here: http://www.troelsgravesen.dk/SBA-941.htm

Stay tuned. 

 16th October 2018

Please to announce the ATB, AudioTechnology-BlieSMa

Click image to go to website.


 28th September 2018

Client work has taken quite some time this summer and culminated with a visit to the hifi show in Guangzhou mid-September - and with an unexpected home trip delay due to hurricane Mangkhut. Guangzhou only some 100 km north of Hong Kong.

Yours truly presenting a new 2½-way anniversary construction with Ellipticor drivers.

In pipeline are two smaller two-way constructions from AudioTechnology, BlieSMa and ScanSpeak drivers. The AT driver is a powerful 6I52-17-06-SDT, with titanium voice coil former in a compact design supplemented by the BlieSMa tweeter, either Al/Mg or Be dome.

The Loudspeaker has been sold and packing these monsters in two pallet crates is something I'll try to avoid in the future. Not easy! Packed 125 kg/ea. I'll miss these speakers badly but space is a serious issue.

Later this year the FUSION/FUSION-BAD will be on sale. Fitted with the bass passive crossover and FUSION FA252 plate-amp/DSP it can be wired to run either fully passive or semi-active. To be announced later.
Also for sale will be the top drivers of the Illuminator-5 including the crossover for mid-upper-mid-tweeter. To be announced later.

AudioTechnology-BlieSMa set-up.

 1st July 2018

Spring and summer has been unusually hot here in Denmark and doing cabinet work on the Ellipticor-4 has been slow, but here they are. For the size, I believe the best 4-way I have ever build. Building this type of cabinets is tedious, and having built four others in the same design doesn't leave many challenges, except for the panel cutting. Cutting Baltic birch and having the final finish in one is demanding, but seeing the finished cabinets I'm pleased and its worth all the hours.
The rear firing tweeter is optional and I'm still experimenting. Seems good on some recordings and less on others. It provides some additional airiness to the sound, but also a more diffuse treble presentation. I'm currently experimenting with an insanely expensive copper foil cap for the tweeter - and it's really, really hard to hear any difference to the default Alumen-Z capacitor, but a certain recording having a forward sounding clarinet, seems a little smoother than it use to be without loosing transparency. I've done A-B test for guests and mostly they couldn't hear any difference. Fine-tuning speakers never end.
This is the holiday season for most people, and I wish you all some relaxing weeks - and maybe some panel cutting.

 14th June 2018

Much to my surprise, The Loudspeaker has caused much more attention than anticipated. Building a speaker of 300+ gross litre was something I just had to do without any expectation of public interest. Visitors have been many and apparently there are quire a few out there with a favourable WAF situation and not least being tired of speakers not delivering the dynamics of real world music. I won't reiterate the virtues of large speakers like these, only pass on the notion made by visitors that treble from a hornloaded driver is something else and in this case as far away from "PA sound" as can be. "Horn treble" has a bad reputation, but from quality drivers, well designed horns and properly tuned crossovers, it can be as smooth as should be and leave conventional direct radiators behind.

Having a new reference obviously add pressure on the smaller speakers from my workshop, and few drivers have excited me more than the new line of Ellipticor drivers from ScanSpeak. As said in the very first article on Ellipticor, Ellipticor 1, it takes time to get to know new drivers, their strengths and limitations. Fortunately client work has added deeper knowledge and given me new ideas. Clients may suggest things you wouldn't dream of and sometimes lead to new ideas for future constructions.

Currently I'm testing the new 8" Ellipticor drivers, 21WE/4542T00, to find out what I can make from this driver.

Click image to view large

Can it be used in a simple two-way or how about an 8+6+1 Ellipticor? Time will tell, but preliminary test suggests a potent bass, transparent up-front midrange - and it can be run from a single coil delivering a 2nd order roll-off.

I'm still in the final construction phase of the Ellipticor-4 making the midrange and treble cabinets. Bass module is finished.

 13th April 2018

These last two winter months have been busy and lots of good stuff in pipeline for launch over the next month or so. To the left a speaker to end all speaker building - if you have the space! 307 gross litres is what it takes to get very very close to what live music may sound like in your living room. 18" BMS bass driver is just the right size to give a kick drum or a double bass the weight and punch of the real thing. 10" midrange driver and a compression driver delivering as smooth and transparent a treble as can be. Not show is a super-tweeter on top handling the upper octave, 10-20 kHz. None of the drivers ever work hard to deliver thunderous sound levels should this be needed. A normal listening level the cones hardly move at all. Extremely low distortion! Go to The Loudspeaker website.

To the right a new 4-way speaker that is already a serious competitor to my ATS4-HE speakers. My ATS4-HE prototype cabs her holding the ScanSpeak Ellipticor drivers on top and 10+12" bass drivers from 18th Sound and BMS. System is tuned to 92 dB and is ~100 gross litres more acceptable, you get and midrange presence and treble transparency similar to the monsters to the left, only not capable of playing as loud.
Setting up the Ellipticor drivers in cabs similar to the ATS4-HE was almost plug'n play. The 18WE driver, here used for midrange is as smooth as can be and crossover is extremely simple. The D3404 tweeter does well with a tweeter baffle similar to the ATS4-HE and again, a very simple crossover.
I won't have time to make the final Baltic birch cabinet before launch, but construction is finished and will be launched shortly.

Construction launched. Go to website.

 25th Feb 2018

Thanks to Lars Frandsen, HIFIcentrum/Middelfart, space was offered for displaying the FUSION-BAD at a local hifi show. Speakers were driven from YBA IA350 amplifier and speaker cables were pure silver from BKS (no website).
I think quite a few visitors were surprised to see DIY at a hifi shown, and to my recollection finished DIY speakers have never been displayed like this before. Maybe back in the Eighties, but not sure.
Anyway, it was a great opportunity to present and demonstrate the speakers and the Jantzen Audio Kit. Response was positive. Quite a few never considered the possibility of cutting MDF, heating up the soldering iron and building something with a solid bass response and significant sound stage - and NOT paying a minor fortune!
One of the many things I learned from the show, was to remember having some 20 cm stands for the speakers. Chairs are too high and few people never had an opportunity getting into proper listening positions like sitting in your sofa at home. Standing up and you're even further away from auditioning speakers properly, although we often have to due to the number of people present.
Moving your speaker into a hotel room is kind of gambling with regard to acoustics, but thanks to all the stuff present and people not least, acoustics were better than anticipated.
All in all: Great fun!  

 16th Feb 2018

It's with sadness I hear Ejvind Skaaning passed away on 8th February, 2018. Ejvind Skaaning was a key figure in the formation of ScanSpeak, Dynaudio and AudioTechnology, the latter now owned by his son Per Skaaning. If you want to dig deeper into the merits of Ejvind Skaaning, read the story here by Claus Futtrup (Chief Technical Officer, SEAS/Norway): http://www.cfuttrup.com/history/ejvind_skaaning.html


Above a picture from the window of the local HiFi Klubben store. Appears they think vinyl aficionados are old farts with shaky hands and just risen from a - hopefully - good night's sleep... From a marketing perspective, this may not exactly encourage young people to get involved, but who cares? Vinyl lives its own life and is doing well.
Have an audiogd R2R 1 DAC for testing for the time being. This DAC certainly brings new life to my 24 bit files. I'm not saying you have to be a digi geek to get this DAC going, but it helps. The manual is a disaster and I recommend reading this 6moon review of its larger sibling to get an idea of what you may have to go through. Have to say that a recommended 1000 hours of burn-in is ludicrous. When it comes to the sound of the R2R 1, I highly recommend you take a listen.

Lots of things have been launched recent 2 weeks:

Bookshelf speaker, specifically tuned to near-wall/bookshelf placement

Finally the Ellipticor-1 is ready for launch

FUSION-BAD is the 2nd variation of this speaker, delivering 500 watts to the bass driver from its Hypex module

Last, but not least, the ATiRi will be ready soon


 9th Jan 2018

First of all, Happy New Year to all who visit my website!

Primary focus this January is the launch of ATiRi and Ellipticor speaker kits. Jantzen Audio is awaiting drivers from the manufacturers and as soon they become available, the kits will be launched.

Next in line is the final touch to the FUSION speaker. Front grille and a version featuring the Hypex PSC2.400d module, running the bass driver including its 200 Hz low-pass filter section. This will be ready before the end of January.

In pipeline is a book-shelf speaker. Yes! First construction meant to be placed on a shelf up against the front wall. Quite a powerful 3-way from 8+4+1 inch drivers. Placing a speaker up against a wall takes special precaution in designing the crossover as we have a significant bass-lift from such placement, meaning from lower mid to treble, the level must be higher than normal to balance the overall sound.

Stay tuned!

 13th Nov 2017

Apparently I should communicate more often here. Have mails asking if I'm still "there". Indeed so, but house maintenance, holidays, etc. has keep me busy. And please do not expect a new speaker construction every month. This is way above my capacity.
Another thing that has keep me busy is selling speakers. This takes time! With the output over the last year it has taken considerable time to get rid of the speakers again. All speakers must go at some point in time. I live in a small house and can only accommodate a fairly small amount of speakers and the bigger ones are hard to stove away - and sell. Few people buy seriously expensive speakers.

New constructions are in the pipeline. Still waiting for the final Ellipticor tweeters to finish off the construction. Hopefully before too long. Another smaller two way in pipeline with exiting new drivers. Finally a larger classic 3-way from 12+6+1. PLEASE do not ask for details. Nothing will be revealed before they are finished.

When not occupied with other things, I've immensely enjoyed my Ekta mkII driven by my EAR-861/32wpc power amp. Read below. 

 18th Sept 2017

I'm very pleased to launch this new and up-dated Ekta. Click image to go to page.

The first Ekta dates back to around 2005 and many times I wanted to update this construction based on a client job and not taking into account an optimal front panel design. The result was a 4th order filter to the tweeter and even a notch filter to tame a 7 kHz peak creating quite some sibilance if not attended. I believe I can do better today by combining design and acoustics at the very beginning. And not only that, I think I can make a more sensitive speaker, better bass, better power handling, better midrange, a better sounding treble - and not least, at lower price! The latter due to the use the the D2608/913000 tweeter, which is kind of an overlooked tweeter, originally derived from the Peerless HDS series. There's a lot of money to be saved from not using the 7000 ring-radiator. The money saved can be used on better crossover components. The 9130 tweeter simply delivers top-notch treble performance with its double magnet, die-cast face plate, low-mass diaphragm, low Fs, etc. Running the Ekta mkII from my EAR 868 pre-amp and modded EAR 861 power amp makes one hell of a system. I'm afraid I have to keep the Ekta mkII as a reference for a modest sized and slim 3-way floorstander.

 25th August 2017

Click image to go to construction page

Based on feedback, the NOMEX-164 is one of the most popular speakers in my portfolio. The mkI dates back to 2010 and with the experience gained since then it's time for an update with some modifications allowing a simpler crossover and a lower point of crossover. The speaker now features a better sounding time-aligned 2nd order filter. The NOMEX cones still deliver some of the best midrange money can buy and the 9130 tweeter a treble that ranks among the very best. With 90 dB sensitivity and an easy load, this speaker can be driven from low-wattage/high-quality amplifiers.
Moving the speakers to my living room and setting up the speakers next to my reference ATS4-HE one might expect some serious shift in quality and some mental adjustment. Not al all! All I can say is that I fully understand why some people would question the rationale in investing some 10 times the money for the ATS4-HE compared to NOMEX 164-mkII. Yes, we pay dearly for small increments in quality. No, the NOMEX does not have the low-end weight of the ATS, but nevertheless a solid bass presentation and magnificent midrange and treble. Feed them the best source material you have and they will deliver. These speakers can be fully driven from my 32 wpc EAR 861 tube amp.

 17th June 2017

The last three months have been very busy. First and foremost due to two new constructions made for ScanSpeak to present their new drivers at the Munich High-End Show, 2017. A classic 3-way featuring the new 11" bass driver, 28W/4878T00, the new 8 Ohm Revelator midrange, 18M/8631T00, and a 2-way stand-mount from brand new Ellipticor drivers. The latter not least exiting due to elliptical voice coils, something never seen before. I very much look forward to more constructions with these exiting new drivers. The 2-way presented in Munich will be launched as a kit around November 2017.

Already around Christmas 2016, the new ATS4-HE was initiated and finally launched a couple of weeks ago. This is the most ambitious and expensive speaker I've ever made - and has brought me closer to the live performance than anything else I've ever had i my living room.

What characterises two of the new constructions is the use of DSP/plate amps for the bass driver(s). I've used bi-amping for several years but the plate-amps featuring DSP is just simply the way to go for larger speakers. It allows rock solid and deeper bass from smaller speakers - and it allows people to adjust bass level to fit their often less than ideal room acoustics. So much needed! I haven't made any statistics, but I think there were more constructions this year in Munich featuring plate amps for the bass drivers than last year. I'm sure it will catch on and be standard for larger speakers in the future. Hypex is launching a wider range of DSP/plate-amps, Fusion, later this year and I'm looking forward to learn their new products. So, why not full DSP and digi amps for all drivers? Simply because what I've hard from digital amps and DSP simply doesn't match the quality of the best of traditional solid state/tube amps and good quality passive crossovers.

Our attic has been stuffed with speakers, and a few weeks ago I launched a summer sale to make room for new constructions. Fortunately four set of speakers have already been sold. The Illuminator-4 is still available and it will probably take a bit longer as it is not exactly cheap, but a kit price of 3900 EUR + cabinets materials + 250 hours of work doesn't come cheap. I really hate to let go of this speaker. It's a darn good speaker and the best woodwork I've ever made. Hopefully it will find a room somewhere delivering what it is capable of. It deserves the best equipment you can buy.
Buying stuff is usually a matter of a few clicks. Selling stuff takes time, a lot of time! Typically 20-40 mails back and forth before a deal is final, money transfer and thorough packing to ensure safe arrival.

 15th April 2017

It's been a long wait for the SBAcoustics Beryllium domes - and it was worth the wait. Standard testing can be found here. Implementing these domes in three of my SBA constructions was easier than anticipated, as frequency response and sensitivity is so much alike the TW29RN tweeter that no changes to the crossovers were needed.
Updates can be found here:
SBAcoustics SBA-10 with Be dome, TW29BN
SBA MW16 MTM with Be dome, TW29BN
SBA MW19 with Be-dome, TW29BN

At around 300 EUR/ea, they should reach a wide audience. Can't believe how good domes we have these days!



 25th March 2017

The winter months are the busiest DIY months of the year. The majority of speaker kit parcels leaving Jantzen Audio goes to the Northern hemisphere and whenever it's cold, people go to their workshops and - among other things - build speakers. So, there have been a lot of mails and diy-service this winter and little time for the new constructions planned. Apart from restoring Lenco turntables I've done quite some work on digital amps for the bass section of larger speakers and in particular programmable digital amps allowing whatever slopes needed for our bass drivers, and not only this, but also allows us to equalize bass performance to suit our mostly horrible home acoustics - and horrible speaker placement not to forget. Most people never get the best of their investment due to speakers having to be placed up against walls or in corners.
Hopefully this will result in some new constructions later this year.

Having used bi-amping for several years I've always wondered why speaker companies producing larger speakers not more often use bi-amping or plate amps for their 10-12-15 inch bass drivers and offer a kit where you simply do not need to buy a 200 watt solid state that not only deliver the amperes needed but also have a great midrange and treble performance. We all know how difficult it is to make heavy muscle amps that can both deliver amperes for the bass and smooth mid-treble performance. There's no sonic rationale for having a single amp doing it all. I heard great 200-300 watt amps at the Munich show last year, but the prices were out of this world. We're talking 20-50 kEUR for a decent sounding amp like Ypsilon, Nagra and others. 2 x 400 watts can be had for less than 200 EUR these days and all it takes is a pre-amp with double output running a workhorse for the bass and your 20-40 watt pet amp handling mid and treble.
Vandersteen is a manufacturer that cleverly use a plate amp to run the bass drivers - and also features extensive bass equalisation. Well done! Why don't Wilson Audio speakers not come with a plate amp taking the heavy load of running the bass drivers in their larger systems? Plane silly to my mind, but marketing always wins and the customer is always right.  

I guess it's a conceptual thing. Apparently the audience for such speakers do not see their system that way, rather two speakers with passive crossovers and two serious mono-blocks running it all. High-end is also show-off and conservative in appearance.
Any thoughts on this and you're welcome to report.

I obviously follow the launch of new speaker drivers from my preferred range of manufacturers - and sponsors. What I've noticed is quite a range of midrange drivers with 4 Ohms impedance. Why 4 Ohms? We can't use these midrange drivers without applying serious attenuation. What we need is 8 and 16 Ohms midrange drivers as long as you guys don't produce bass drivers that allows us to make speakers with an overall system sensitivity above 87-90 dB. I know, I know! If you target 90+ dB sensitivity we're talking 80-120 litre cabs and few people build speakers that size.
I'm currently doing a crossover for a 3-way with a 4 Ohm bass driver allowing a system sensitivity around 88 dB and still I would need a 16 Ohm midrange driver if I was to avoid attenuation resistors. But nope! 4 Ohms is what we have if we want a midrange driver. Has to be said ScanSpeak does make 4"/8 Ohm midrange drivers, but what about 5" and 6"? All of my 3-4 way systems use attenuation resistors for the 6"/8 Ohms midrange drivers. I'm afraid marketing wins again, because if they did make 16 Ohm midrange drivers, nobody would probably buy them being afraid of running out of sensitivity.

 13th December 2016


This Autumn/Winter has been busy on client work and some projects have been postponed, but this SBA MTM should emerge some time in January 2017. As mentioned in the SBA-10 construction file I initially set up a small 2-way from MW16 and TW29 and was surprised from what I heard. So how about two MW16 and we have some 238 cm^2 membrane area, more than most 8" drivers. Initial simulation suggests a very simple crossover. Cabinet will be easy, a skinny rectangular box that should be easy for most diy'ers having a handheld saw and a router. I only used tape and a few clamps for gluing cabinets, so very few tools needed.

To reduce my stock drivers, I made the above 3-Way Classic kits for sale incl. front panels and ready made crossovers. I made three kits, all sold by now, with premium components, HDF front panels and Superior-Z in critical places of the crossover. Wires, terminals, ports, all ready for mounting.

I recently went to a client from last winter to fine-tune/check his gigantic 4-way system. These are not speakers you bring in the trunk of your car to my workshop! 18" bass driver, 12" midrange and horns for the rest. 115 kgs/ea. Active crossover at 200 Hz and the rest is passive. I brought my laptop and DAC and finally heard a few tracks as they should sound. With a system sensitivity of 100 dB/2.8V the dynamics are scary! These speakers can cause tinnitus you'll have to live with for the rest of your life!
There are very good reasons I don't go this route myself, as I simply don't have room for such giants. And as always with horns there are things that finally sounds right, but there also things where horns have their very special way of dividing your record collection in good and bad.

I guess it's time to wish you all some happy holidays ahead. Thanks for all mails and suggestions coming in this year. It's been an exiting year and should I point to some highlights it will be the SBA-10, Illuminator-4 and not least the Munich exhibition i May. Go there and find out how different we think reproduced music should sound, from tiny 3" drivers to gigantic horns. It's a treat and Munich can be really nice in May. 

 November 2016


It has been busy times and a new Up-Grade filter for the vintage B&W 802 s3 has been launched. Click image above to go to page. Next in line is an Up-Grade kit for the successor of JBL-L100, the L112. Click images to go to websites.

To the right a new speaker, the SBA MW19. This features the SBAcoustics MW19-8 driver, which is large 7" driver and delivers a credible bass from only 20 litres and one of the most transparent midrange I've ever done. Having such a large driver requires a good tweeter that can handle a low point of crossover and like the SBA-10, I use the SBA TW29RN-B, which has become one of my favorite tweeters. In reality a ring-radiator due to the fixation of the membrane at the center. This speaker features a healthy 8 Ohm impedance, minimum 6 Ohms, and my GlowMaster tube amp loves it. The SBA MW19 was perceived as a studio monitor, but is equally suited for domestic use. Highly recommended if you want a big small speaker.

 Sept 2016


Click image to go to website

Pleased to present my first construction dedicated for corner/near-wall placement. Based on the fact that most people have to place speakers near walls or close to corners due to simple lack of space or spouse having specific ideas on living room decor. And also based on the fact that most people enjoy music while doing other things, they hear music while others (few) listen to music (audiophiles). Now, I'm also sure the latter group do not necessarily enjoy music more than the former group. Quality is highly subjective.
Setting up these speakers in various rooms in our house was a rewarding exercise in how the rooms played their different roles in shaping the overall sound. Moving the speakers a little back and forward with regard to front wall and side walls impacts the sound and experimentation is imperative in getting the sound you like the best.
Making the cabinets was fun. They are so easy to make, just like the very first speakers I made in the Seventies. What I couldn't do back then was making a very simple series crossover, delivering a flat response with point of crossover exactly where I wanted it. Only really good drivers and proper measuring gear and simulation software can create such results from so little. Only 4 (four) components in the crossover.

We're into the Autumn months now and during the summer months I have made plans for the rest of the year and probably into 2017. Six speaker projects where preliminary modeling suggests interesting 2-to 3-way speakers for smaller systems. No big speakers in pipeline. Two of the projects are mkII versions of former constructions, an Ekta mkII and a NOMEX-164 mkII also. The reason for these mkII version is that I think I can do better today than 10+ years ago.
Two SBAcoustic speakers are in pipeline, a d'Appolito from MW16 and and small two-way for studio monitoring from the MW19 driver. Obviously a "Studio Monitor" can be used domestically like any other speaker. There's nothing special about a studio monitor unless a manufacturer make a black cabinet and claims it for studio monitoring.
So, stay tuned - and please do NOT ask when they will be ready or any other detail. Thanks!

 August 2016

ScanSpeak Illuminator-4

It's summertime and time for house maintenance and fighting vegetable garden weeds. It's time for harvesting greenhouse cucumbers and tomatoes. The taste is unbelievable! It's time for bicycle rides and beech picnics and all the things we enjoy about summer here high up on the Northern hemisphere. The sun goes down a quarter to ten in the evening.
It's also time to make plans for Autumn and winter months and there are lots of plans, which I shan't reveal now. May and June spare time was spent making the upper cabs for an Illuminator-4. I set up a tweeter panel for the 7100 tweeter and made the Ill-4 crossover - and I'd forgotten why I had the Ill-4 running for three months before engaging in the Ill-5 construction.
This construction dates back more than a year and went before the Illuminator-5 but I got caught up on making the ultimate ScanSpeak and left the Ill-4 for later. It takes time to make the upper cabs but I'm pleased with the result. Just waiting for the final crossover components and it'll be ready for launch.
Understandably few engage in Ill-5, although a few kits have been sold, due to cost and cabinet complexity. The Ill-4 i more manageable and cabs can be made very simple if the above doesn't match your workshop tools. It takes a good table saw to make the above, but as you will see later, it can be made very simple as long as front panel dimensions are kept.
I dare say it belongs to the three best speakers I've ever made.



If the Illuminator-4 is above your budget you may take a look at the SBA-10. It's been in my living room for three months not and I don't even miss my ATS-4 reference speakers. For the price it's unbeatable and the only thing that makes a (very little) difference to the ATS-4 and Illuminator-4 is the dedicated 8" upper-bass driver. The SBA-10 even goes a bit deeper and the Satori tweeter for sure puts a question mark to the use of beryllium domes, that's how good it is. Working down to 1.5 kHz it handles all of the treble range - and it pays off. Pays off big time! One thing I was pleased to hear from visitors was how small it is. This was my intention with the cabinet design. It's a potent 10+6+1 speaker and level 2 is 2200 EUR! Frankly, you have to spend serious money on any commercial design to match the performance of this speaker. 

Finally I have some 10" high-efficiency drivers suitable for 3-ways for sale. Check my sales page: http://www.troelsgravesen.dk/sale.htm

 May 2016


Guess it's been a while since last update. The cabinets for the SBA61-NAC gave the opportunity to launch three monitors with different flavours due to cone materials and crossovers. Click images above to go to websites.
My keeper is the SBA61-NAC, maybe because it the first I made - and maybe because I want to play it to visitors who may have some prejudice against alu cone drivers. I really like the sound of this speaker.
There are now four different 3-Way Classics with the addition of the SBAcoustics version. The SEAS, ScanSpeak and SBAcoustics are all in the same price range where the AudioTechnology is for the tasty cost-no-object audience. The AT does has something to offer the others do not - but it comes at a price.

I've had samples of all SBAcoustics Satori drivers and if successful, there will be a relatively compact 3-way from 10+6+1. Probably a couple of months from now.
The Satori tweeter has been tested and added to the two others, click here.

 January 2016

Download the history of Danish Loudspeakers

Click image to download paper (98 MB)

28 December 2015

Thanks to all for reporting back on your constructions in 2015! Always exciting to see ones work in the hands of others.

Christmas holidays have been busy and some updates on AudioTechnology 3WC and Illuminator-5 featuring the SS D3004/604010 Be dome have been launched. This was really quite easy as I only needed to adjust tweeter attenuation and didn't have to make basic changes to the crossover. Only the mini Discovery 12W took a whole new tweeter section - and I'm not expecting many builders here, but should you want the best from a mini, it's worth while.

Tests on two SBAcoustics tweeters have been launched here. In particular the 1" alu dome has impressed me by exceptional low distortion.

The subwoofers have been finished and will be reported soon. Perfect partners for AT-3WC as seen on photo below.

Currently a 3-Way Classic from SBA drivers is under construction. To be launched in January.

Happy New Year!

13 November 2015

It's been quite a while since last posting. The OBL-15s have been on the agenda and also some rather complicated client work including compression drivers and horn-loaded tweeters. Compression drivers are tricky and need careful time-alignment to make crossovers work properly. Whenever I needed a break, I would blow my brains out with the OBLs seen below. These can make whatever can rattle in my workshop - rattle!

22-11-2015: Now launched here.

I'm waiting for crossover components to make the final boards and it shouldn't be long before launch. Please do not ask for details before launch. Thanks.

Next I've had some 26W/4558T00 subwoofers from ScanSpeak and I hope to launch my experiences before the Christmas holidays. Not that there will be any news here as the 26W drivers and the Hypex 4.0 plate amps have been reported elsewhere, but I want to report some experiences from mating the subs with my Discovery 12W, my Ellam 98 mkII and the AudioTechnology 3WC to pick a range of speakers from being very small to what I see as middle-sized (AT-3WC). Subs don't make a pair of shoe-box speakers big but for some the very low-end oommph is enough.


I've had a pair of the new ScanSpeak Be domes, the D3004/604010, and have reported here. I'm looking forward to make versions of the Illuminator-5 and the AudioTechnology 3WC with these domes. And why not the Discovery 12W as already done? The ultimate mini.


Last, but not least, Director of Sales and Marketing, Bo Albrectsen, SB Acoustics, paid me a visit to hear my stock speakers - and offered sponsorship of their drivers. I couldn't be more pleased. I've done a few SB Acoustic drivers for clients and I'm looking forward to try out their products in 2016. Below a selection of drivers I picked for 2-3 constructions. Primary target is a classic 3-Way, an "8+4+1". Normally I would be hesitant to dig into alu cone drivers. I did some NNNN alu cone drivers 10+ years ago and they were horrible, but the 6" here from SBA looked very promising from specs. Initial testing looks promising too and this driver may very well find its way into future constructions. The 1" alu tweeter has been tested and will be reported soon (read here). Exceptionally low distortion all the way down to 1 kHz and exceptional dispersion too. Really impressive.

06 September 2015

As discussed on the Illuminator-5 pages, drivers' dispersion characteristics has been on my mind lately as it has such an immense impact on perceived sound. We may have a 2-way (6" + 1") and a 3-way (e.g. 6" + 3" + 1") and they may have exactly the same frequency response and they may very well have identical horizontal dispersion and yet sound like night and day. There are many reasons for this being partly the intrinsic dispersion characteristic of the drivers, the crossover topology and drivers' overlap. The latter I find interesting as a 6" like the ScanSpeak 18WU, having a rather large and deep cone, soon starts beaming toward higher frequences (Beaming: Put your hand around your mouth like a conical horn and say something. You'll notice the change in sound as you prevent horizontal dispersion. This is what drivers do when we reach a frequency having a wavelength equal to the diameter of the cone).
The 18WU has a 14 cm cone diameter equal to 2457 Hz (34400/14). Above this frequency the driver will loose dispersion (as can be seen from data sheet). Already at 2000 Hz we have reduced response at 30 degree off-axis. Right! We place our point of crossover 2 kHz and we're safe. Not exactly, because depending on the slope of our crossover we may still have an "echo" of this "beaming" present in our perceived sound. The more shallow our slopes, the more reminiscens of "beaming".
Cone shape and material plays its role too. Some 6" drivers have a fairly shallow cone and proper designed dust cap and may be less prone to beaming. The very old version of the Vifa C17WH had a very shallow cone and a wide dust cap and had a wonderful midrange projection with little tendency of beaming. Using soft paper cones may have reduced the problem even more as not all parts of the cone would produce high frequences. With modern hard cones we like to reduce cone break-up and all parts of the cone should do all frequences. Very well, the price to pay is increased beaming and some take point of crossover down to 1.5 kHz from 4th order crossovers to make a 2-way from "6+1". This takes very good tweeters as most 1" domes start producing significant levels of distortion around 1 kHz. Many of the ScanSpeak tweeter are safe with a 4th order crossover at 1.5 kHz.
OK, then we make a 4th or 6th order filters to prevent this and yes it works, but adds to overall complexity and cost - and maybe not the sound we were looking for. Getting 2, 3, 4 or even 5 drivers to make a coherent sound is so full of compromises that there is no right, only clever choices and preference. One reader called my current preference for LR2 filters my "comfort zone" and requested more diversity. Well, he may be right, but the last ten years of speaker building has proved the LR2 - to me - a good compromise between cost/complexity and performance and I'll stick to this until I find something better. 

Click image to go to AudioTechnology 3-Way Classic

Above my most recent construction, a powerful 3-way from AudioTechnology drivers and the superb ScanSpeak R3004/602010 tweeter. I've really come to love these small tweeters, R3004/602010 (R for ring-radiator) and D3004/602010 (D for conventional dome). The 15H52-0613-SDKAM midrange has a tremendous midrange projection and the level of transparency equals any fancy new cone material like ceramics, composite carbon-whatever, Rohacel, etc. This midrange driver spews music into the room and I never thought I'd say you can place this speaker up against a wall and not get that usual "closed-in" sound from boosting the bass due to room-gain leaving the midrange distant and with lack of detail. The 15H52 will still help making a credible soundstage. Now, don't get too exited, the speaker will still sound better being on stands out on the floor.
The AT-3WC proves a dynamic headroom above any other speakers I've made of this size and should you want the 20-40 Hz range also, add a decent subwoofer. You don't get it all from 2 cubic feet.

08 July 2015

The summer holidays are ahead and with the speaker shown below, I very much feel like taking a few weeks off. This has been the longest project ever, not least due to the woodwork.

Click image to go to website

Cost-efficiency, contrary to the Discovery-4, has not been an issue here. All the best ScanSpeak can produce is going into this 5-way speaker. Besides a potent bass system, the primary aim here is to do something about dispersion in upper-mid/lower treble. Thus, the 12MU has entered the system, providing a dispersion and a presence quality the usual "6+1" rarely manage, unless special drivers and low point of crossover is used.
Enjoy your holidays!

01 May 2015

Buying is easy! A couple of clicks and you have made your purchase. Selling takes ages! I'm having a sale of some of the stuff accumulated over the last ten years. I didn't realise I had that much surplus hifi on the shelves!
Selling takes time and sometimes provides you an unexpected insight into how people handle their finances. "I want to buy...", sometimes means "I would like to buy if I had the money, but fact is I don't...".

Some of my surplus components went into the the design above, the Revelator 4R, featuring the more sensitive, un-coated and more lively version of the ScanSpeak 5" Revelator bass drivers. Click image to go to page. I've had a few requests on this driver and here it is. For tweeter I picked the R2604/832000.  

27th March 2015

With the two center speakers above I hope to fill a gap in the portfolio of floor-standers suitable for surround sound. The Prestige version can be build for a modest investment, where the Excel version will take you a little further in sound quality. Key parametre for center speakers is even horizontal dispersion, thus is must be 3-ways and 4th order LR between mid and tweeter.
Click images above and go to page of CENTER-641!


Click images to go to website

This micro from Discovery W12/8524G00 and R3004/602010 is meant to be used for desktop application and where space is seriously limited. And why not make your kids get used to good sound from an e.g. NAD 3020D amp, being fed from a laptop or other digital sources? The DISC-12W may be a way to better sound culture.
There are, and have been, many excellent 4" drivers and I clearly recall the Vifa PL11 range of drivers as some of the best at that time.
Fortunately ScanSpeak has some excellent 4" drivers and here I picked the 8 Ohms version from the Discovery series. To supplement this excellent wide-range driver I use the R3004/602010, which basically is the same as the costlier R3004/662000 but in a smaller package suitable for limited space. Click here.

7th Februar 2015

Click image to go to page.

Finding second hand 50 EUR old Lenco turntable has become a hobby and the dark winter evenings are fine for doing some restoration work. These two above are the 3rd and 4th and I have two more in store, both L75s. I found an L78 on eBay at reasonably price and wanted to see how it may differ from  the L75. The basics are the same, only the arrangement around on-off button and the brake function is different. I'd still recommend the L75 if you have the choice as it is simpler to renovate. My second L75 was made for a client, here seen above with a Moerch DP 8 Precision tonearm. Having both a 9" and 12" Moerch tonearm it's obvious to make comparison and I'm afraid the 12" is more of a theoretical advantage over the 9". Are we really able to the hear the slightly increased tracking error from a 9"? Time will tell when I make a more systematic comparison of the two arms with the same cartridge.
You may ask why I need two turntables - and I don't. I just love restoring these 45 year old decks. It's relaxing and highly satisfying when set it up and start listening records.

Click image to go to website.

I had hoped to launch a bigger 3½-way system in December but two months of work on the crossover just left me more and more frustrated with the treble performance, hence the project was ditched. Sometimes we just have to give in and start all over. Well, the bass drivers stayed the same, only this time I used the ScanSpeak 18W/8535-01 for mid and the R2604/833000 for treble. One afternoon of work and the crossover was done! The mid and tweeter appeared to be a match in heaven. The rest was fine-tuning and the overall voicing of the speaker. The bass drivers are from the ScanSpeak Discovery series, 8" and 10". Basically it's an ATS4 from modest priced drivers, except for the midrange drivers, the most important of them all.
What's seen above is meant to be a seriously large speaker from a very modest investment. All drivers alone are 790 EUR. What I've tried is to spend the money where it counts: The midrange driver and the crossover components' quality. I haven't experienced any driver that didn't benefit from good quality crossover components.
The cabinet is designed to be as easy as possible and something for any diy enthusiast with a little experience in wood working.
Speaker construction launched. Follow link here.

13th December 2014

Above the Ellam Disc 15 and DTQWT-mkIII, the latter at the photoshoot. This was the finale for 2014. Eight new speakers and two updates, 8008-Center, QUATTRO mkII. I had hoped to launch the new ScanSpeak 12WU mini/Be dome, but it seems it will have to wait for the new year.
Mails are pooring in this November/December, certainly the time of the year where speaker building speeds up to culminate in January/February.
Looking back there seems to be a trend towards either very cheap constructions or very expensive constructions. The ATS4 and NEXT4 have created much more attention than anticipated and the number of people currently engaged in constructing the ATS4 was unexpected. What also has appeared are quite some newcomers, and also some people that may have trouble finishing the projects, either due to lack of experience in woodworking or simple soldering of the crossovers. But there's a beginning for everyone and I strongly advise not to start up on some of the more complicated constructions. Speaker building can be addictive and once succeeded, there may be more to come.
What appears to never end is the perception that a crossover is a crossover and that front panels can be made to personal taste and skills. The number of times I copied in this link is uncountable: http://www.troelsgravesen.dk/crossovers.htm
The link tells that if you want to make any of the constructions here, you must follow front panel design and drivers' placement, otherwise you'll need a new crossover and I cannot help without having your speaker in by lab. What's behind the front panel is not without importance, but here there is room for creativity. The stepped baffles are there for a reason (better sound) and you cannot mount the drivers on a flat baffle without a new crossover.
The page also tells that whatever drivers you have on the shelf, I cannot make you a crossover because crossovers cannot be calculated and they cannot be made from manufacturers' data sheet. Every driver's response is dependent on the baffle on which is is placed and the crossover must be constructed accordingly.
Thanks for all the response over the last year. Feel sure that everytime a question to one of my constructions appear, I consider updates with further information and details and suggestions. Keeping the website alive is done every single day.
I wish you all some relaxing holidays ahead  - and happy workshop hours!
Thanks to my three sponsors for providing the drivers and crossover parts needed. Without their help and support things would have looked very differently.

Just had these babies in for 2015 projects. Preliminary measurements suggest equal performance to large-faceplate brothers.
These tweeters allows very close to midbass placement and reduced crossover lobing. Time will tell.

October 2014

Launching a new high-effiency driver is a daunting task and it's taken almost a year before the first production batch reached Jantzen Audio. In particular the edge coating took time; the right glue, the right amount, the right place, etc.
It goes without saying a new driver must be better than the old one. The aim of launching a new driver was low-loss. A new voice coil former combined with the phase plug increased Qm from 1.7 to 10! Low-loss mean better dynamics and that micro details are not getting lost in mechanical and electrical damping. Click image below to go full details.

The new 8008-HMQ driver is not compatible with the old JA8008, thus new TQWT and DTQWT crossovers are in prepartion and will be released this November.

Click image to go to page


click image to go to page

Restoring an old turntable, making the plinth and setting up a new arm is at least as much fun as mounting new cabinets with drivers for the next speaker. Click image above and read why I love turntables and vinyls.

Three new speakers are finished and one already launched, the Ellam-98 mkII. The other two speakers are waiting for the main speaker driver to be released from the factory. One is the 12WU fra ScanSpeak mentioned in the June 2014 speaker-talk. I hope the 12 WU will soon be ready. The third speaker...time will tell.

The Ellam 98 mkII is one I've wanted to do for a long time as I think the 9800 dome deserves much more attention. It's been around for many years and I don't think any alu dome has been made that does it better than this one. To my ears it does as well as the Accuton C30 ceramic dome.
Making a stepped baffle allows true time- and phase-coherent LR2 filter to be implemented, a key design feature that justifies an mkII version. Besides this, it's an easy speaker in terms of woodwork. 

August 2014

After the ScanSpeak Discovery Classic 3-Way, I just had to do an upgrade of the popular SEAS 3-Way Classic, thus the SEAS 3-Way Classic mkII, delivering increased sensitivity and a better and simpler crossover from retracting the tweeter some 20 mm. This allows implementation of a true LR2 filter and adds smoothness to the treble performance and mid-tweeter integration.

The two contenders above

Please do not ask which one is the best. Thanks! And enjoy!