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The all new NA12

I have just shipped the first pair of NA12's. The data for this system can be seen at my website.

Please note that this system is "passive". There are a lot of very smooth speakers out there these days thanks to DSP, but DSP is not a solution without its limitations. It isn't viable for many people. I know of no other passive crossover speaker that comes anywhere close to the performance of the NA12 (The new NS15 is active). This puts this speaker in a class all its own for those who prefer not to go active.
 
Other than the 1dB more sensitivity and the higher freq extension, what does the new design have over the Abbey?

Thanks,
Kelvin

Hi Kevin - sorry to take so long responding. I did not see a notice that this thread had a response.

I think that the NS12 is very close to an active Abbey, but a bit better than the passive Abbey. It is a better choice if passive is a requirement, but otherwise an active Abbey is probably the better choice. The NS12 does have some aspects that may not show up well on the polar map, such as a much more rigid and well damped enclosure, and less weight.

Basically all my speakers are very close to each other with ever smaller improvements as the models go up. It takes more and more resources to drive out the last vestiges of error in the design so the prices go up more than the performance. There is no question that the sweet spot is the Abbey. The kit form is really a bargin when you compare it to the marketplace.
 
I would have the same question as Kelvin.

Dr Geddes, Is it possible to buy Minidsp unit and upload your files to go active with passive Abbeys I have?

Tomek

I don't make my active program publicly available. I could sell you a preprogrammed miniDSP, but that is risky since it assumes the latest DE-250 drivers, not older ones. So, if your speakers are older you would have to replace the compression drivers as well.
 
Hi Kevin - sorry to take so long responding. I did not see a notice that this thread had a response.

I think that the NS12 is very close to an active Abbey, but a bit better than the passive Abbey. It is a better choice if passive is a requirement, but otherwise an active Abbey is probably the better choice. The NS12 does have some aspects that may not show up well on the polar map, such as a much more rigid and well damped enclosure, and less weight.

Basically all my speakers are very close to each other with ever smaller improvements as the models go up. It takes more and more resources to drive out the last vestiges of error in the design so the prices go up more than the performance. There is no question that the sweet spot is the Abbey. The kit form is really a bargin when you compare it to the marketplace.

Good to know :)

Thanks for the reply. It explains a lot.

Kelvin
 
In reply to:
(...) I don't make my active program publicly available. I could sell you a preprogrammed miniDSP, but that is risky since it assumes the latest DE-250 drivers, not older ones. So, if your speakers are older you would have to replace the compression drivers as well.(...)


I have to check the CDs in my Abbeys for their version. I own a DEQX which basically does the same job as Minidsp. It would be also easier for me to arrange a Minidsp here and check if I like a change for the active route. Just remember that with Minidsp I would be limited to 24/96 files so no higher res or DSD files. I can try with my DEQX first. Is there anything I should know about the necesarry measurement. Have you performed your measurements on-axis or 22 degrees off axis as advised for listening. I know there is a hole on the frequency response when the speakers are on-axis. If my Deqx fixes that hole it would probably make it worse off-axis. Am I right?

Thanks,
Tomek
 
Yes, the material is the same, but it is 33% ticker and the construction is a little different to improve the structural damping.

Remember that the stiffness of a plate goes as the thickness squared so a 33% thicker plate is 1.33^2 times stiffer, nearly double.
 
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In reply to:
(...) I don't make my active program publicly available. I could sell you a preprogrammed miniDSP, but that is risky since it assumes the latest DE-250 drivers, not older ones. So, if your speakers are older you would have to replace the compression drivers as well.(...)


I have to check the CDs in my Abbeys for their version. I own a DEQX which basically does the same job as Minidsp. It would be also easier for me to arrange a Minidsp here and check if I like a change for the active route. Just remember that with Minidsp I would be limited to 24/96 files so no higher res or DSD files. I can try with my DEQX first. Is there anything I should know about the necesarry measurement. Have you performed your measurements on-axis or 22 degrees off axis as advised for listening. I know there is a hole on the frequency response when the speakers are on-axis. If my Deqx fixes that hole it would probably make it worse off-axis. Am I right?

Thanks,
Tomek

Hi Tomek - missed this post before.

I do not use any single angle for setting up my crossovers. I look at the Directivity Index (DI) and the response to get the best compromise between these two measures, looking for a flat/smooth DI and a slightly falling SPL response, optimized for angles between 15 and 25 degrees.

Yes, optimizing for a flat response along any one axis will definitely degrade the sound quality of one of my designs.
 
Earl, in my view you are an advocate of high fidelity in the traditional sense (before the term got devaluated): what comes out should resemble what goes in as best it can. In line with this, I've never understood why you think the amplitude response of your speakers should have a downward slope. Is it to compensate for a relatively low DI at high frequencies in comparison to the lower midrange? I mean, conventional box speakers have lower DI than your speakers at low/mid frequencies, but similar DI at high frequencies.
 
Keyser

Of all the things that I do, this is one of the only ones based on experience. A flat on listening axis just seems to sound bright with a CD speaker. I do believe it is the DI that is doing this when compared to the very narrow HF response from the direct radiator.

I am not the only one to find this, Toole also suggest a subtle downward tilt to the listening axis response. HFs are just not that prevalent in our environment and too much of them can sound un-natural. We can easily generate 10+ kHz directly into someone's ears but in nature these frequencies just do not travel very far (air absorption skyrockets above 10k), our environment is basically devoid of them.

Remember that we are not talking about extreme values here - 3 dB @ 10 kHz tops.
 
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Thanks Richard,

This is also quite possible. Clearly there could be several factors, but the consensus about the speaker design world is that the direct sound and the reverberant sound should fall slightly, i.e. the listening axis and the power response should both fall slightly. This results in a flat Directivity Index across the board.
 
Most of do mix on "flat" speakers, but far too many of us hype up the high end. Those of us that master these often have to deal with it. Also a lot of us do not like to listen to the flat speakers we work with. I think Earl certainly made the right call and it is a minor but important call.
 
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Joined 2012
Thanks Richard,

This is also quite possible. Clearly there could be several factors, but the consensus about the speaker design world is that the direct sound and the reverberant sound should fall slightly, i.e. the listening axis and the power response should both fall slightly. This results in a flat Directivity Index across the board.

I understand the slightly falling response is to better mimmick what I might hear further away - like in a large concert hall...... However, I rarely go to such places from where i live and only listen to sounds which are generated near me. When I get the chance, I like to listen up close to a small group playing acoustic instruments. Thus, for Me, a flat response sounds most like what i hear near me. Comment, pls. Can there be a switch for both positions?


THx-Richard Marsh