|
|
Post by Boomzilla on Jun 20, 2020 21:14:35 GMT -5
I’m not talking about mediocre implementations that require extra A-D/D-A conversions (such as used on the Crown XLS-series amps), but rather DSP done purely in the digital domain. My Roon streaming software, for example, offers DSP. But my experience with it in multiple systems is that the instant that any DSP is enabled, the transparency of the sound is completely lost, and the expensive system sounds like an AVR.
I’d LIKE to have both flat frequency response AND transparency to the sound of the recording, but via DSP, the two seem mutually exclusive. Why?
|
|
|
|
Post by MusicHead on Jun 20, 2020 22:01:14 GMT -5
DSP is a rather general term. You could say that even a multichannel decoder is a form of DSP. Room correction sure is DSP. As far as Roon is concerned, I do not have direct experience. However, being the curious type that I am about everything electronics, I found this quite interesting: kb.roonlabs.com/DSP_EngineIt appears that using Roon's DSP capability comes with several caveats, such as headroom management, Signal Path, CPU utilization, etc. Not getting one or more of those right may cause who knows what unwanted effects. Processing being the "P" in DSP, it means that it is doing something to the original signal. One may contend that the least a signal is processed, the better. To the caveats above I would add proper algorithms implementation. Just because there is no A/D and then D/A conversion, it does not mean that a bad implementation in the digital domain cannot utterly ruin the sound. |
|
|
|
Post by Boomzilla on Jun 20, 2020 23:23:54 GMT -5
As did I. Need to check this for sure! |
|
|
|
Post by audiobill on Jun 21, 2020 6:42:47 GMT -5
Boom, flat in-room frequency response is not appealing to most people in most cases. That's why most dsp equalized systems typically incorporate a "house curve" that typically boosts lows by 6db, and pulls down highs by 6db. The dirty little secret with dsp is that "house curves" are a season to taste variable, so in the end act as just ordinary tone controls or equalizers.
Do some googling on house curve and you'll see. Yet another case of listening trumping measurements in the final analysis.
Best to really focus hard on room placement of speakers, based on REW measurements, and appropriate room treatments. Then call it done.
All the obsession with Dirac is misguided, IMO, except in HT systems where there are many speakers to equalize, a fool's errand to get right.
(Dons flame retardant suit)
|
|
|
|
Post by foggy1956 on Jun 21, 2020 6:54:00 GMT -5
Boom, flat in-room frequency response is not appealing to most people in most cases. That's why most dsp equalized systems typically incorporate a "house curve" that typically boosts lows by 6db, and pulls down highs by 6db. The dirty little secret with dsp is that "house curves" are a season to taste variable, so in the end act as just ordinary tone controls or equalizers. Do some googling on house curve and you'll see. Best to really focus hard on room placement of speakers, based on REW measurements, and appropriate room treatments. All the obsession with Dirac is misguided, IMO.(Dons flame retardant suit) Always come back to preferring my music in reference stereo as opposed to anything Dirac offers, got an extra suit😎 |
|
|
|
Post by Boomzilla on Jun 21, 2020 8:14:06 GMT -5
Boom, flat in-room frequency response is not appealing to most people in most cases. That's why most dsp equalized systems typically incorporate a "house curve" that typically boosts lows by 6db, and pulls down highs by 6db. The dirty little secret with dsp is that "house curves" are a season to taste variable, so in the end act as just ordinary tone controls or equalizers. Do some googling on house curve and you'll see. Best to really focus hard on room placement of speakers, based on REW measurements, and appropriate room treatments. Agreed - Roon has no "house curve." It's user supplied filters only. All the obsession with Dirac is misguided, IMO, except in HT systems where there are many speakers to equalize, a fool's errand to get right. Absolutely agreed! |
|
|
|
Post by audiobill on Jun 21, 2020 8:25:59 GMT -5
So you do have the ability to use filters and para eq together in Roon, but that proves the point.
|
|
|
|
Post by mfeust on Jun 21, 2020 10:49:24 GMT -5
Boom you can go eat at McDonalds or at the finest restaurant in your town. Where do you think you'll have the better experience?
Mark
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 21, 2020 12:04:00 GMT -5
Boom, flat in-room frequency response is not appealing to most people in most cases. That's why most dsp equalized systems typically incorporate a "house curve" that typically boosts lows by 6db, and pulls down highs by 6db. The dirty little secret with dsp is that "house curves" are a season to taste variable, so in the end act as just ordinary tone controls or equalizers. Do some googling on house curve and you'll see. Best to really focus hard on room placement of speakers, based on REW measurements, and appropriate room treatments. All the obsession with Dirac is misguided, IMO, except in HT systems where there are many speakers to equalize, a fool's errand to get right. (Dons flame retardant suit) Back in the 80s-90s when I was installing audio and security systems in automobiles I remember when DSPs were introduced. Equipped with RTA meters judges in audio shows would judge a system based on how flat the in car frequency response was. Never thought any of them sounded good when producing a totally flat frequency response. Including at that time car audio systems that approached a hundred thousand dollars. |
|
DYohn
Emo VIPs 
Posts: 18,489
|
Post by DYohn on Jun 21, 2020 14:53:42 GMT -5
Bah, don't use the EQ functions in Roon. Very limited. What are you trying to accomplish?
|
|
|
|
Post by Boomzilla on Jun 21, 2020 21:46:34 GMT -5
Boom you can go eat at McDonalds or at the finest restaurant in your town. Where do you think you'll have the better experience? Mark I understand neither the relevance of the question nor any intended analogy. |
|
|
|
Post by Boomzilla on Jun 21, 2020 21:47:30 GMT -5
So you do have the ability to use filters and para eq together in Roon, but that proves the point. All filters in Roon are considered DSP. |
|
|
|
Post by Boomzilla on Jun 21, 2020 21:50:45 GMT -5
Back in the 80s-90s when I was installing audio and security systems in automobiles I remember when DSPs were introduced. Equipped with RTA meters judges in audio shows would judge a system based on how flat the in car frequency response was. Never thought any of them sounded good when producing a totally flat frequency response. Including at that time car audio systems that approached a hundred thousand dollars. Although I'd agree about car audio, I've found that relatively flat response DOES sound best in my living room. Because I'm running Roon on an older computer, I'm strongly suspecting that the CPU is running out of cycles while trying to apply Roon's filters. I'll check this theory tomorrow. |
|
|
|
Post by Boomzilla on Jun 21, 2020 21:54:33 GMT -5
Bah, don't use the EQ functions in Roon. Very limited. What are you trying to accomplish? I was trying to apply a very mild "tone control" to the bass region and to mildly tweak the high treble (15KHz center). But either of these filters, applied through Roon, has the INSTANT effect of flattening all dynamics and making the otherwise excellent sounding system lose its imaging totally. The easiest fix is to turn off the DSP & restart Roon with DSP disabled. But I'd still like to thoroughly understand why the DSP causes these effects. |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 21, 2020 23:10:44 GMT -5
Back in the 80s-90s when I was installing audio and security systems in automobiles I remember when DSPs were introduced. Equipped with RTA meters judges in audio shows would judge a system based on how flat the in car frequency response was. Never thought any of them sounded good when producing a totally flat frequency response. Including at that time car audio systems that approached a hundred thousand dollars. Although I'd agree about car audio, I've found that relatively flat response DOES sound best in my living room. Because I'm running Roon on an older computer, I'm strongly suspecting that the CPU is running out of cycles while trying to apply Roon's filters. I'll check this theory tomorrow. Understandable, your pleasure while listening matters most. Just suggesting that in AV THX reference levels are 105/115db. Obviously there's a curve which I haven't even looked up yet. I have yet to get a mic and run a signal to my system from my PC some 30 feet from the entertainment room. I really need a laptop. Point being is I suspect my curve is much more drastic as I prefer bass heaviness. It's preference. While I expect vocals and instrumentation to be clear, pronounced, and loud enough to not be drowned out I also want enough bass to stand the hairs up on the listener's neck. |
|
|
|
Post by mfeust on Jun 22, 2020 8:16:57 GMT -5
Boom you can go eat at McDonalds or at the finest restaurant in your town. Where do you think you'll have the better experience? Mark I understand neither the relevance of the question nor any intended analogy. The DSP in Roon compared to DSP in say something like the McIntosh MEN220. Which do you think will sound better. Mark |
|
DYohn
Emo VIPs
Posts: 18,489
|
Post by DYohn on Jun 22, 2020 8:18:47 GMT -5
Bah, don't use the EQ functions in Roon. Very limited. What are you trying to accomplish? I was trying to apply a very mild "tone control" to the bass region and to mildly tweak the high treble (15KHz center). But either of these filters, applied through Roon, has the INSTANT effect of flattening all dynamics and making the otherwise excellent sounding system lose its imaging totally. The easiest fix is to turn off the DSP & restart Roon with DSP disabled. But I'd still like to thoroughly understand why the DSP causes these effects. It's because the DSP in Roon is a software solution so it is only as good as whatever the programmers could do. Who knows what the exact mechanism might be. If it doesn't sound good in your system don't use it, same as anything else. |
|
|
|
Post by Boomzilla on Jun 22, 2020 8:25:47 GMT -5
mfeust said "The DSP in Roon compared to DSP in...the McIntosh MEN220. Which do you think will sound better." Digits are digits. If properly implemented, I'd expect them to sound EXACTLY the same. We aren't dealing with analog conversion here - there are no capacitors or resistors to cheap out on. In effect DSP is purely software - no filters for analog conversion - no noise-shaping - this is math, pure and simple. The ONLY difference I could hypothesize is the ability of the CPU to keep up with the conversions. If the McIntosh has a dedicated DSP processor and the Roon is using the host computer's clock cycles (which it is), then if the host computer is insufficiently powerful to manage the real-time DSP, then I could see how the Mac might sound better. However, assuming the host computer has CPU cycles to spare, there should be absolutely no difference in sound until DA conversion is done. Boomzilla
|
|
|
|
Post by garbulky on Jun 22, 2020 9:56:51 GMT -5
mfeust said "The DSP in Roon compared to DSP in...the McIntosh MEN220. Which do you think will sound better." Digits are digits. If properly implemented, I'd expect them to sound EXACTLY the same. We aren't dealing with analog conversion here - there are no capacitors or resistors to cheap out on. In effect DSP is purely software - no filters for analog conversion - no noise-shaping - this is math, pure and simple. The ONLY difference I could hypothesize is the ability of the CPU to keep up with the conversions. If the McIntosh has a dedicated DSP processor and the Roon is using the host computer's clock cycles (which it is), then if the host computer is insufficiently powerful to manage the real-time DSP, then I could see how the Mac might sound better. However, assuming the host computer has CPU cycles to spare, there should be absolutely no difference in sound until DA conversion is done. Boomzilla A DSP's algorithms vary. That's probably the differences you'd hear, not so much the clock cycles. Though th eclock cycles would matter if the algorithms require a lot of complex processing. For instance in AVR's most DSP's will resample the signal to 48khz as there is not enough power to manage hi res signals. In this case it is the algorithm used that makes the difference. But the reason why it sdoes so may be related to cpu cycles, but it could also be related to the preference of the designer. |
|
DYohn
Emo VIPs
Posts: 18,489
|
Post by DYohn on Jun 22, 2020 12:49:53 GMT -5
mfeust said "The DSP in Roon compared to DSP in...the McIntosh MEN220. Which do you think will sound better." Digits are digits. If properly implemented, I'd expect them to sound EXACTLY the same. We aren't dealing with analog conversion here - there are no capacitors or resistors to cheap out on. In effect DSP is purely software - no filters for analog conversion - no noise-shaping - this is math, pure and simple. The ONLY difference I could hypothesize is the ability of the CPU to keep up with the conversions. If the McIntosh has a dedicated DSP processor and the Roon is using the host computer's clock cycles (which it is), then if the host computer is insufficiently powerful to manage the real-time DSP, then I could see how the Mac might sound better. However, assuming the host computer has CPU cycles to spare, there should be absolutely no difference in sound until DA conversion is done. Boomzilla No two DSP solutions sound the same. It's data manipulation. The way it's manipulated will vary depending on the programmer. |
|
