Go to on this page: It’s been well over three years since I finished my ATS-4 speakers.
BMS 12N and some others too – Forums
I’ve made quite a few speakers since then, but the ATS-4 are still my reference speakers to measure any new construction against. 12h630, the ATS-4 is my number one. Habit is a strong partner. We get used to a certain sound and we like it, and this is the way we want our system to sound.
BMS 12N 12 Watt Neodymium Speaker 4 Ohm
One thing always stood out in all tests against the ATS-4, efficiency! The ATS-4 is significantly more efficient than any other similar system I have built, approx. For the same box volume we must decide how efficiency and low-end extension should be balanced. Some people will argue that efficiency is not that important, because watts are cheap. True, but good watts are not I can tell.
I heard some seriously good amps at the Munich High-End Show this year and last year, but prices were out of this world. I recently upgraded my GlowMaster KT88 with better – and gms expensive – caps, and I think it can compete with the best you can find.
Only limitation is power. It’s rated at 65 watts, not bad at all, but not suited for driving heavy ” bass drivers. High-efficient speakers will always bring out something 126n30 good sounding amps and source material in a way low-efficiency speakers do not, even if power is adequate for average listening levels.
High efficiency drivers have better energy transfer compared to low-efficiency drivers and has been my bmss sincewhere this was put together: I like where I live and intend to 12n360 here with my 24 sqm living room.
And horns have their own problems, which I won’t dig into here. There are a few tricks left to further increase efficiency of a speaker similar in size to the ATS-4, because this is the size that allow my wife and I to use our living room for relaxing, social activity, TV watching, etc. I’ve been using bi-amping since I built the ATS-4 and this brings me to a topic I have been wondering about for long.
Why do not more high-end speaker manufacturers large speakers, that is use a plate amp for the bass drivers? Vandersteen does it and plugs in a plate-amp with 11 dials on the rear to adjust bass response to real world living rooms. Last Munich exhibition, Maydisplayed some high-powered amps sounding really, really good. The only problem was price. Below Hz it doesn’t nms what an amp sounds like as long as it can deliver amperes!
And this is both easy and cheap these days. There may be another more subtle reason for so few high-end speaker systems utilising plate amps for the woofers.
Maybe this is not how customers perceive their stereo system. A high-end system comprises a pair of integrated speakers with passive crossovers and a pair of impressive mono-blocks running all of it! Or a EUR digi amp apparently doesn’t go with a pair of Kondo mono-blocks! The way we visualise our system may be a strong determining factor for the commercial success of a speaker system. Heck, have a plate amp made on a 10 mm slant of aluminum!
And add some copper sockets, etc.
If it has to look like a million. I think I did se more plate amps used at this year Munich show.
Some good watts are mostly 12h630 we need to run a midrange-tweeter combo on top of our bass system. Even from speaker systems down to dB efficiency.
Many tube amps can do this and a few solid state like the First Watt J2 from Nelson Pass despite its low gain. I tried the J2 recently and it has qualities I could live with was it not for my current GlowMaster.
I love my GlowMaster.
BMS 12N630 – 8 Ohm
Now, let’s get to the issue here. Rather than a 10″ bass driver we need a 12″. These are the targets: The 12″ driver 12n60 BMS 12N This is an unusual driver from a PA driver perspective. Too good to be true? Well, it depends on where at the SPL data we look. Last, but not least, we ask the plate-amp to boost response some dB with below 50 Hz.
Voila, we have something in the area of 92 dB down to around 30 Hz.
I’d say 92 dB down to 35 Hz is excellent. To make dB bjs Hz takes Xmax 8. I’ve had very good experiences from both suppliers.
BMS 12N630 and some others too
Next we need a 10″ upper bass driver and after some discussion with Per Skaaning at AudioTechnology we decided on making a 10″ Flex Unit with the needed sensitivity and with a standard voice coil DCR delivering a whopping 94 dB on an infinite baffle.
The cone material is PP to match the sonic signature of the midrange. We’re using shallow sloped crossovers here! This 10″ driver is something, I can tell. For mid and tweeter we can use the same drivers as for the ATS This time no series resistors to the midrange driver!
No need for lower DCR voice coil or more uF to the midrange. What came in later was the addition of a 8″ passive radiator to help the 18H52 at the low end just to get a little more level in its band-pass area. The benefit from this is arguable, but it did something to the sound of the midrange, and I liked it. The SS Be dome has no trouble following the target here. Obviously the crossover is completely re-designed compared to ATS You may ask if all this for 3 dB really matters?
Only thing I can say is that every 3 dB matters! More responsiveness, better dynamics, more live feeling, closer to the real thing. And our amplifiers have to do less! Plus 3 dB means half power for the same SPL level. You may ask why not aim higher. Why not 95 dB? The answer is size. It’s all a matter of balancing size, efficiency and low-end extension.
We can have it all if size is not a constraint – but here it is. Not cheap – and wasn’t mean to be, sorry. After several months of service, I can still go to my system in the morning and say: The sound is as vibrant, as dynamic, as transparent as I had wanted for. I have no idea how to make a better speaker for my 25 sqm living room.
And the cabinets are starting getting the patina I like too. Takes a year or two to get the final glow. The finished speakers in their pale fresh coating. In a couple of years they’ll get the deeper glow of my current ATS4. Click images to view large. A lot, but please read this: Any change to front panel design and drivers’ placement and you need and new crossover and I can’t help. And please, all of it before writing. New kid on the block, the C-Quenze “23” frame and a passive version. Helps the 18H52 in its lower band-pass area.
The actual PR units do not have terminals. Second new kid on the block: This simply is an awesome driver and very important for the efficiency of this speaker system.
Frequency response of 10C77 measured at AudioTechnology. Quite nice frequency response too! The workhorse for all of the above drivers, handling the lower bmw. This BMS driver is supposed to be moving air – and it does. With its 3″ voice coil it handles some watts and it does whatever we ask the Hypex modules to do. The BMS bass drivers can be purchased from Thomann, very reliable source: Contact Per Skaaning at: Go to FA page for further instruction.
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