Speaker Talk 2014-16

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 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!

June 2014

The last three of months have been busy. Two speakers from ScanSpeak drivers. A capable 3-way from Discovery drivers delivering an awful lot of good sound for a very modest price tag - and the other a very small and rather expensive mini-monitor from new drivers not even ready for release yet. The ScanSpeak Classic 3-Way has been on the to-do list for a very long time and the Discovery drivers were not even developed at the time as my initial thinking was around the Classic series of 22W/13M/1" dome. However, these affordable drivers deliver quality we didn't dream about some 20 years ago. Better voice coils, more linear response, etc. The level of transparency these Discovery can deliver is quite remarkable and it's all up to low-loss suspensions and rigid cone materials with modest - and ear-friendly - break-up modes. The ScanSpeak 3-Way Classic will be launched soon. The mini features all-new drivers, a 12WU-something (final name not decided yet) and the small-size beryllium dome, D3004/604050 (not on the ScanSpeak website yet). The speaker was developed for the ScanSpeak exhibition at High-End Munich 2014. If you need cost-no-object minis for your laptop system - or smaller rooms - this might be an option. The 12WU is made from a combination of PP and alu cut up in the pattern of the Illuminator cones and glued together again, delivering extended linear response and the best sound I've ever heard from a 4". The Be dome, well, does what we expect from such a construction. A stepped baffle allows LR2 filter and transparency is exceptional. The 12WU features 2.5 litre volume and it was quite a challenge to fit in ports and crossover in such small volume as can be seen below.

12WU crossover mounted on rear panel.

Music last, but not least, a lot of time has been spent installing a new tonearm on my Lenco L75 turntable and getting to know proper set-up better by doing actual measurements. A protractor has been acquired and the Adjust+ software from Feickert Analogue is currently being tested. An article on why I listen to vinyl rather than digital is in preparation.