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Post by marcl on Jul 11, 2021 5:07:48 GMT -5
I was actually poking at our southern US friends who can't help the DIE-rac and DEE-rac  While I'm one of those southerners you reference(really a transplant from the north), here in Tallahassee, FL, we had the honor of having Paul M. Dirac for the last 10 years of his life as a professor of Quantum and Theoretical Physics at Florida State University. Even the FSU Science Library is named after him, which leads me to the purpose of this post, the librarians when I was at FSU would correct those students of the pronunciation of his name, which the southern drawl does not do his last name justice. I've heard good things about Dirac and his time there. Apparently he was generous with his time and very helpful to students. |
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Post by marcl on Jul 11, 2021 5:21:25 GMT -5
audiophilestyle.libsyn.com/dirac-research-interview"Audiophile Style talks to Dr. Mathias Johansson, Dirac Research co-founder and chief product officer, about the beginnings of the company in Upsala Sweden, its work with BMW, the current Dirac offerings for audiophiles, the differences between Dirac software and Dirac built into hardware, and many general DSP & room correction topics." It's 1:15 long, but worth listening to especially if you have never heard Mathias speak. A few interesting points I had not heard before ... - IIR filters handle minimum phase correction and FIR filters handle non-minimum phase correction. (Note: PEQ filters in AV processors, miniDSP, etc are generally only IIR filters)
- Dirac used frequency dependent windowing in early versions, but they now have a "more robust" (proprietary) solution.
- One good reason to use Dirac full spectrum and not just on the bass, is that Dirac uses time delay (phase) correction to align frequency bands. This alignment improves impulse response across the whole frequency band.
- Some customers - knowing their personal hearing loss characteristics - tailor their target curve to compensate.
- Some of the best imaging and overall response Mathias has heard using Dirac has been with electrostats and a subwoofer.
Finally ... based on listening to Mathias say "Dirac" dozens of times .... it's "Di-RAC" ... not " DEE-rac" or " DIE-rac" ... just sayin'  I've been a proponent of FIR filters for years. You actually have to READ the stuff at the MiniDSP Website (GASP!) to find those products with the computing power for FIR filters. Like the 2x4HD.....to start. Than you have to figure out HOW to use 'em......a real learning curve. What a concept! Time Allign. Never saw THAT one coming. maybe 'stats (and by extension Maggies?) sound good is that the SINGLE diaphrapgm is a single planar 'launch' for a wave. No driver setback to create time align issue. Does anybody CARE how it is pronounced? Tricky stuff trying to use the FIR section in the 2x4HD. First they say get rePhase to calculate the taps. I got it to run once and couldn't really figure it out. Then I couldn't get it to run again. Folks at Dirac emphasize time and again their secret sauce is the use of the mixed phase filters, the algorithm to determine minimum phase and non minimum phase corrections, and their time domain correction. Most people ignore this. I've been using Dirac with Maggies for three years and it works great - despite advice from Magnepan that room correction software doesn't work will with their speakers so you should just not use it. One reason Dirac works so well with Maggies (and stats) is as you say ... the planar "launch" makes for fewer issues in the impulse response to begin with. Dirac refines and aligns and makes it that much better. Sometimes startlingly so with transients. I have my front 3.7's in what's called the "Rooze" configuration bouncing 45 degrees off the side walls. The MLP is in the dipole null. But what does Dirac see for impulse? It sees the strong reflection off the side wall plus some earlier leakage around the speaker sides of both in-phase and out-of-phase sound ... makes for a messy impulse that their algorithm has some trouble sorting out. So I've developed a work around that's pretty successful. |
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Post by exitium82 on Jul 13, 2021 19:42:10 GMT -5
With my XMC-2, if I add a second subwoofer, will I see it in Dirac?
Will it sweep it and EQ it the just as it does with the other one?
Thank you
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ttocs
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Post by ttocs on Jul 13, 2021 19:53:28 GMT -5
With my XMC-2, if I add a second subwoofer, will I see it in Dirac? Will it sweep it and EQ it the just as it does with the other one? Thank you If each sub is on a different output then Dirac will see each sub. Dirac only sees outputs. If there are multiple subwoofers attached to one subwoofer output, Dirac sees the one output, not multiple subwoofers attached to it. |
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Post by exitium82 on Jul 13, 2021 22:54:29 GMT -5
With my XMC-2, if I add a second subwoofer, will I see it in Dirac? Will it sweep it and EQ it the just as it does with the other one? Thank you If each sub is on a different output then Dirac will see each sub. Dirac only sees outputs. If there are multiple subwoofers attached to one subwoofer output, Dirac sees the one output, not multiple subwoofers attached to it. What would the benefits be off their multi sub software? I thought I remembered reading that Dirac on the Gen3's didn't handle multiple subs correctly in it's current iteration. I want to add another sub! Thanks and sorry if this has been asked allot before. I read a bunch in this thread, just wanted to make sure |
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Post by exitium82 on Jul 13, 2021 23:24:14 GMT -5
I wanted to make sure that dirac would see it. I'm perfectly comfortable doing it manually using REW.
I'm curious to know why allot of people want DLBC if dirac is still correcting response and time between multiple subs
Or maybe I'm looking for excuses not to spend more money lol.
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ttocs
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Post by ttocs on Jul 14, 2021 2:35:42 GMT -5
I wanted to make sure that dirac would see it. I'm perfectly comfortable doing it manually using REW. I'm curious to know why allot of people want DLBC if dirac is still correcting response and time between multiple subs Or maybe I'm looking for excuses not to spend more money lol. Dirac will see the subs connected to each of the three subwoofer outputs of the processor and calibrate each one. But Dirac will not calibrate all three together, and this is what DLBC will do with great advantage when it works as advertised. |
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Post by oleops on Jul 14, 2021 12:56:57 GMT -5
Dirac live adjust each sub on seperate output individualy and not together. Dirac multisub use the sum of bass and evens out the total, in short. The issue mentioned has been solved but think it is still on betatesting. More important is that thus far Emotiva can't use DLBM But there is no reason for not adding the second sub even without DLBM, some experimenting in placement could give good results... google Todd Welti and soon you have four subs  or look at some papers from Earl Geddes ... you could look at MSO also. |
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Post by leonski on Jul 14, 2021 15:30:28 GMT -5
Why does everyone omit what might be the originl paper on the subject? www.harman.com/documents/multsubs_0.pdfWritten when Welti worked for Harman International....as head acoustician...or whatever his title was.... IMO? At least glancing thru the papers IN ORDER WRITTEN will lead to the most modern thoughts and modeling of multiple subs in a real space.. |
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KeithL
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Post by KeithL on Jul 14, 2021 15:49:15 GMT -5
Note the conclusions... which are quite interesting... Why does everyone omit what might be the originl paper on the subject? www.harman.com/documents/multsubs_0.pdfWritten when Welti worked for Harman International....as head acoustician...or whatever his title was.... IMO? At least glancing thru the papers IN ORDER WRITTEN will lead to the most modern thoughts and modeling of multiple subs in a real space.. |
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Post by marcl on Jul 14, 2021 17:42:16 GMT -5
Why does everyone omit what might be the originl paper on the subject? www.harman.com/documents/multsubs_0.pdfWritten when Welti worked for Harman International....as head acoustician...or whatever his title was.... IMO? At least glancing thru the papers IN ORDER WRITTEN will lead to the most modern thoughts and modeling of multiple subs in a real space.. Or hear it from Welti himself ... www.youtube.com/watch?v=V-6goLs1szM |
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Post by leonski on Jul 14, 2021 21:13:24 GMT -5
Deepends which 'aperture' you prefer learning with.
ME? I like text where I can go slow and reread as necessary to a video / PowerPoint presentation......
After all? Welti was the author and on the team which wrote the original white paper.....
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Post by marcl on Jul 15, 2021 6:33:49 GMT -5
Deepends which 'aperture' you prefer learning with. ME? I like text where I can go slow and reread as necessary to a video / PowerPoint presentation...... After all? Welti was the author and on the team which wrote the original white paper..... The link I posted is not Welti presenting his paper from years ago. It's an interview with him that was recorded in May 2021. He discusses several topics including the multi-sub research. Some other relevant and interesting interviews (all done in 2021): Floyd Toole www.youtube.com/watch?v=TcTydBUd8WcAmir from Audio Science Review www.youtube.com/watch?v=PhcJC7i_j3IEthan Winer www.youtube.com/watch?v=yUmt8knPs0M&t=2sEarl Geddes www.youtube.com/watch?v=nhe8VfuTg08I was quite surprised by one thing Welti said in the interview. I'm curious if anyone else responds as I did. |
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KeithL
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Post by KeithL on Jul 15, 2021 11:20:05 GMT -5
The Todd Welti video is VERY interesting...
I'm normally inclined to prefer white papers to lengthy video chats...
However, while he does ramble a bit, he has a LOT of interesting things to say...
And I think a lot of people on our forums might want to adjust their perspectives a bit after hearing what he has to say.
(Some may find the part that starts a bit after 45 minutes in to be especially interesting... although I personally don't find any of it especially surprising.)
Deepends which 'aperture' you prefer learning with. ME? I like text where I can go slow and reread as necessary to a video / PowerPoint presentation...... After all? Welti was the author and on the team which wrote the original white paper..... The link I posted is not Welti presenting his paper from years ago. It's an interview with him that was recorded in May 2021. He discusses several topics including the multi-sub research. Some other relevant and interesting interviews (all done in 2021): Floyd Toole www.youtube.com/watch?v=TcTydBUd8WcAmir from Audio Science Review www.youtube.com/watch?v=PhcJC7i_j3IEthan Winer www.youtube.com/watch?v=yUmt8knPs0M&t=2sEarl Geddes www.youtube.com/watch?v=nhe8VfuTg08I was quite surprised by one thing Welti said in the interview. I'm curious if anyone else responds as I did. |
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Post by marcl on Jul 15, 2021 12:52:36 GMT -5
The Todd Welti video is VERY interesting...
I'm normally inclined to prefer white papers to lengthy video chats...
However, while he does ramble a bit, he has a LOT of interesting things to say...
And I think a lot of people on our forums might want to adjust their perspectives a bit after hearing what he has to say.
(Some may find the part that starts a bit after 45 minutes in to be especially interesting... although I personally don't find any of it especially surprising.)
The thing that surprised me the most was when he was talking about a conversation with a guy, and when the guy told him he had one listening position Welti told him multiple subs wouldn't be worth doing. That is just weird! I understand the benefits of multiple subs for evening out response over a wider area than one seat. But the physics of waves propagating from opposite ends of the room, cancellation of some harmonic resonances ... and the fact that it's easily measurable at a single point that multiple subs improve the response ... very strange to me that he would say that. |
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richb
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Post by richb on Jul 15, 2021 15:10:48 GMT -5
There are no placement options for my two Rythmik E22 subwoofers. These work much better than the single Velodyne 15 woofer. The first improvement is to remove localized bass. The LFE channel can deliver bass up to 150 Hz that is clearly localized. There is a big bass hump that mostly cured using the delays. The rest I can address with RMC-1 EQ.  - Rich |
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Post by marcl on Jul 15, 2021 15:13:54 GMT -5
There are no placement options for my two Rythmik E22 subwoofers. These work much better than the single Velodyne 15 woofer. The first improvement is to remove localized bass. The LFE channel can deliver bass up to 150 Hz that is clearly localized. There is a big bass hump that mostly cured using the delays. The rest I can address with RMC-1 EQ. - Rich Where do you have them relative to the room? Can they be placed center of the front/back walls, or center of the left/right walls? Or nearly so? If you do the best you can (including some bass traps if possible) Dirac will make short work of the rest. |
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richb
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Post by richb on Jul 15, 2021 15:17:41 GMT -5
There are no placement options for my two Rythmik E22 subwoofers. These work much better than the single Velodyne 15 woofer. The first improvement is to remove localized bass. The LFE channel can deliver bass up to 150 Hz that is clearly localized. There is a big bass hump that mostly cured using the delays. The rest I can address with RMC-1 EQ. - Rich Where do you have them relative to the room? Can they be placed center of the front/back walls, or center of the left/right walls? Or nearly so? If you do the best you can (including some bass traps if possible) Dirac will make short work of the rest.  There is no room for anything because of large openings and furniture. The Room is 15x30 with large openings. - Rich |
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Post by marcl on Jul 15, 2021 16:05:13 GMT -5
Where do you have them relative to the room? Can they be placed center of the front/back walls, or center of the left/right walls? Or nearly so? If you do the best you can (including some bass traps if possible) Dirac will make short work of the rest. There is no room for anything because of large openings and furniture. The Room is 15x30 with large openings. I can know down the 42 Hz with EQ. - Rich We make do ... I always suspected that architects are taught to design houses, by setting up a home theater system ... then placing a door, window, pole or fireplace wherever there is a speaker, TV or listening position |
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richb
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Post by richb on Jul 15, 2021 16:10:44 GMT -5
View AttachmentThere is no room for anything because of large openings and furniture. The Room is 15x30 with large openings. I can know down the 42 Hz with EQ. - Rich We make do ... I always suspected that architects are taught to design houses, by setting up a home theater system ... then placing a door, window, pole or fireplace wherever there is a speaker, TV or listening position I moved a window to have a place for the HT and TV  - Rich |
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or look at some papers from Earl Geddes ... you could look at MSO also.
