I'm working on the final details of a speaker cabinet.
I'm using B&C 12FHX76 coaxial drivers. I want to hide the speaker flanges, so my idea is to make a plate that covers them, giving the speaker appearance of a rear mount. This idea is about improving the appearance of the speaker, but I want to make sure that it doesn't have a negative effect on sound quality.
I've seen a variety of opinions on the subject, but I don't see any clear concensus. So I took some measurements. Measurements are "raw" data, meaning no EQ. Measurements are taken 18" from the driver, and the microphone was not moved between measurements. (I did time-align the woofer and horn, but that is all.)
I'm attaching the REW measurements in case anyone is interested in playing along. I see small differences, but I don't know either has a problem that I can't fix with DSP. I'm not sure if there is a particular piece of data that would stand out as a problem, so I'm throwing the entire files up for you guys to look at.
-The first measurement is the driver front mounted to a flat baffle.
-The second measurement has a secondary baffle that covers the perimeter of the driver, so it is concealed like a rear mounted driver. This secondary baffle has a 1/2" radius around the driver.
-The third measurement is the "front mount" driver with EQ. I don't see any glaring issues with the post-EQ measurement either, but I'm not an expert.
What do you think? Is one meaningfully better than the other?
My prototype speaker with the "front mount" secondary baffle attached. Just a test. I won't build the cabinet like this.
I'm using B&C 12FHX76 coaxial drivers. I want to hide the speaker flanges, so my idea is to make a plate that covers them, giving the speaker appearance of a rear mount. This idea is about improving the appearance of the speaker, but I want to make sure that it doesn't have a negative effect on sound quality.
I've seen a variety of opinions on the subject, but I don't see any clear concensus. So I took some measurements. Measurements are "raw" data, meaning no EQ. Measurements are taken 18" from the driver, and the microphone was not moved between measurements. (I did time-align the woofer and horn, but that is all.)
I'm attaching the REW measurements in case anyone is interested in playing along. I see small differences, but I don't know either has a problem that I can't fix with DSP. I'm not sure if there is a particular piece of data that would stand out as a problem, so I'm throwing the entire files up for you guys to look at.
-The first measurement is the driver front mounted to a flat baffle.
-The second measurement has a secondary baffle that covers the perimeter of the driver, so it is concealed like a rear mounted driver. This secondary baffle has a 1/2" radius around the driver.
-The third measurement is the "front mount" driver with EQ. I don't see any glaring issues with the post-EQ measurement either, but I'm not an expert.
What do you think? Is one meaningfully better than the other?
My prototype speaker with the "front mount" secondary baffle attached. Just a test. I won't build the cabinet like this.
Check out these guys:
https://www.genuin-audio.de/en/produkte/neo/
My experience and understanding of others doing this, is that you "just" have to follow the curvature or characteristic of the driver in use - on the baffle front. Then diffraction should be kept to a minimum.
Remember that a DSP - or any EQ for that matter - can only "correct" a linear problem. So you have to build a speaker, where the driver and baffle/cabinet together create a uniform dispersion, which is mostly linear and smooth at all angles in front of the speaker - and then you apply EQ.
So it could be, that you have to make the front baffle more steep. Your driver alone is pretty smooth, so you should give it a smoother transition to the baffle, like how KEF does it - even though we can always debate how audible it is.... I personally like to have it as smooth as possible
https://www.genuin-audio.de/en/produkte/neo/
My experience and understanding of others doing this, is that you "just" have to follow the curvature or characteristic of the driver in use - on the baffle front. Then diffraction should be kept to a minimum.
Remember that a DSP - or any EQ for that matter - can only "correct" a linear problem. So you have to build a speaker, where the driver and baffle/cabinet together create a uniform dispersion, which is mostly linear and smooth at all angles in front of the speaker - and then you apply EQ.
So it could be, that you have to make the front baffle more steep. Your driver alone is pretty smooth, so you should give it a smoother transition to the baffle, like how KEF does it - even though we can always debate how audible it is.... I personally like to have it as smooth as possible
I've heard about coaxials and diffraction, but I'm not sure how it presents itself in measurements.
My drivers have a separate wave guide for the horn, so that eliminates intermodulation distortion. And I think the high frequencies detach from the wave guide before they reach the edge, so there should be minimal edge diffraction?
But yeah, I'm not sure how diffraction would present itself in standard measurements. Please comment if you know!
My drivers have a separate wave guide for the horn, so that eliminates intermodulation distortion. And I think the high frequencies detach from the wave guide before they reach the edge, so there should be minimal edge diffraction?
But yeah, I'm not sure how diffraction would present itself in standard measurements. Please comment if you know!
To me, the last year with a KEF coax, has been the smoothest experience for me, where the speaker seem to "disappear" much more in the sound field, leaving me much more in the illusion of listening to the music, more so than the speaker.
So I believe it is worth it, to measure and see if different baffles, filters and EQ make a difference on your design.
KEF sums it up here:
https://us.kef.com/blogs/news/diffraction-explained
I would make another "top/secondary" baffle, with a smoother round-over from the driver to the front, like on the KEF, and see if the measurement proof that you get less anomalies in the measurement. But you have to measure the distance between mic and speaker and gate the measurement, so that you have repeatable/comparable data and only focus on the speaker itself, and not the room.
You can read Linkwitz lab, how diffraction adds new sound sources, that both enhance and counteract the original response of the driver. So that smooth response you often see on a driver in the spec sheet, is only possible with the best possible front baffle layout.
https://www.linkwitzlab.com/diffraction.htm
This is a good guide aswel:
https://www.speakerdesign.net/audioXpress/diffraction/diffraction.html
I kinda hunt the principle of a minimum baffle, for the same reasons mentioned in most threads on diffraction. Until now, it has worked very well for me, and most people listening to my DIY agree
So I believe it is worth it, to measure and see if different baffles, filters and EQ make a difference on your design.
KEF sums it up here:
https://us.kef.com/blogs/news/diffraction-explained
I would make another "top/secondary" baffle, with a smoother round-over from the driver to the front, like on the KEF, and see if the measurement proof that you get less anomalies in the measurement. But you have to measure the distance between mic and speaker and gate the measurement, so that you have repeatable/comparable data and only focus on the speaker itself, and not the room.
You can read Linkwitz lab, how diffraction adds new sound sources, that both enhance and counteract the original response of the driver. So that smooth response you often see on a driver in the spec sheet, is only possible with the best possible front baffle layout.
https://www.linkwitzlab.com/diffraction.htm
This is a good guide aswel:
https://www.speakerdesign.net/audioXpress/diffraction/diffraction.html
I kinda hunt the principle of a minimum baffle, for the same reasons mentioned in most threads on diffraction. Until now, it has worked very well for me, and most people listening to my DIY agree