Does DSP belong in State of the Art Systems?

marty

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as the long time poster boy for an all analog signal path, i've now gone over to the dark side of dsp.

no; not in my 2-channel room. in my Home Theater. sure; in HT everyone is using dsp for multi-channel movie soundtracks, and maybe some music only on the side. no big deal. but i've just purchased a super uber Trinnov Altitude 16 dsp processor. and i plan on listening to music in my Home Theater room for the first time. i want to see how close dsp, done right, can get to the realism of ultimate analog 2-channel.

my Home Theater room is not nearly as over-the-top as my 2 channel room, so it won't be able to go head to head in terms of speaker and amplification quality. but it won't be chopped liver. and those who think multi-channel executed correctly can surpass high level 2 channel can see how that goes.

the audio side of the system will use streaming Roon, an Oppo 203 disc player, plus a Kaleidascape movie server as sources, the Trinnov for the processor, a 9.3.6 surround speaker set-up with 3 Funk Audio 18.0 subwoofers. i will have to do some room treatments in that room to get it right, and i plan on employing a professional set-up guy to optimize it once everything is in place.

will the dsp experience compete for dedicated music-only listening? or will it still be movies and Foley stages only?

i'm hoping that this set-up takes me to a new musical place not otherwise accessible.

note; 16 years ago, i built my 2 channel room as a 5.1 music room, with 5.1 multi-channel SACD's as my source. i made the room wide so i could have rear channels at the correct angles, put conduit in the floor for cables, then invested in the speakers and electronics to do it. 18 months later, when i realized my vinyl seriously kicked multi-channel's butt, i tore all of it out and did not look back.

that was zero dsp multi-channel that could not compete.

here i am again. with ultra dsp.
Fantastic and fascinating! Will look forward to your description of the journey, Mike. I'll also bet you'll have a lot of fun doing this.
Marty
 

Mikem53

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Oct 1, 2020
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as the long time poster boy for an all analog signal path, i've now gone over to the dark side of dsp.

no; not in my 2-channel room. in my Home Theater. sure; in HT everyone is using dsp for multi-channel movie soundtracks, and maybe some music only on the side. no big deal. but i've just purchased a super uber Trinnov Altitude 16 dsp processor. and i plan on listening to music in my Home Theater room for the first time. i want to see how close dsp, done right, can get to the realism of ultimate analog 2-channel.

my Home Theater room is not nearly as over-the-top as my 2 channel room, so it won't be able to go head to head in terms of speaker and amplification quality. but it won't be chopped liver. and those who think multi-channel executed correctly can surpass high level 2 channel can see how that goes.

the audio side of the system will use streaming Roon, an Oppo 203 disc player, plus a Kaleidascape movie server as sources, the Trinnov for the processor, a 9.3.6 surround speaker set-up with 3 Funk Audio 18.0 subwoofers. i will have to do some room treatments in that room to get it right, and i plan on employing a professional set-up guy to optimize it once everything is in place.

will the dsp experience compete for dedicated music-only listening? or will it still be movies and Foley stages only?

i'm hoping that this set-up takes me to a new musical place not otherwise accessible.

note; 16 years ago, i built my 2 channel room as a 5.1 music room, with 5.1 multi-channel SACD's as my source. i made the room wide so i could have rear channels at the correct angles, put conduit in the floor for cables, then invested in the speakers and electronics to do it. 18 months later, when i realized my vinyl seriously kicked multi-channel's butt, i tore all of it out and did not look back.

that was zero dsp multi-channel that could not compete.

here i am again. with ultra dsp.
Good Morning Mike, You take the “Anything worth doing, is worth Overdoing” to new heights !
Kudos to you for your never ending quest for perfection ! Always Enjoy reading about your systems.
 

Solypsa

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(Snip)
Personally I'd love to see some top designers give us options to link up 4 or more high quality DAC channels with common volume control and the ability to use the DSP tools in the digital domain prior to the DAC. In the digital domain the hardware needs to be powerful enough and not cause downstream problems, but with digital input & output, most of the sound differences come from the software execution of filter types and any response correction, and much less from the hardware. ...
I'm pretty much all analog these days so don't look into this much but aren't you describing the typical mastering studio setup? Digital file>dsp>dac channels, often multiple pairs.
(and then analog processing and adc but thats another story...)
 

sbo6

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note; 16 years ago, i built my 2 channel room as a 5.1 music room, with 5.1 multi-channel SACD's as my source. i made the room wide so i could have rear channels at the correct angles, put conduit in the floor for cables, then invested in the speakers and electronics to do it. 18 months later, when i realized my vinyl seriously kicked multi-channel's butt, i tore all of it out and did not look back.

that was zero dsp multi-channel that could not compete.

here i am again. with ultra dsp.
I'm curious why you didn't just move forward in your 2 channel room with the surround sound setup since, while it wouldn't compete with the 2 channel you would still capitalize on the room size, setup and 2 channel system for L and R surround sound?
 

godofwealth

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Peter Walker once commented that using DSP to correct a loudspeaker’s sound was like looking at a Turner landscape using different colors. His preferred solution, of course, was to design a loudspeaker — the Quad electrostatics — that was far less affected by room resonances than dynamic speakers and to correct for directivity issues electronically in the design. One dynamic loudspeaker that does work really well is the Gradient Helsinki, which is designed to be as impervious to room effects as possible — it’s somewhat disconcerting to listen to this speaker on a well recorded classical music album. Your room practically disappears — when you measure the Helsinki, you find room effects are minimal. But a lot of listeners don’t like what they hear because they are so used to the inflated bottom end of most dynamic speakers. The Quads or Helsinki’s sound too lean to them. Accuracy in the end is not what most people want, apparently!

Attached: picture of the Gradient Helsinki in my largish bedroom. Perfect for late night listening. You get this weird psychedelic effect of floating in a large concert hall listening to this strange looking loudspeaker.
 

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schlager

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godofwealth (nice nick) I have never seen a measurement of a speaker in combination with the room, that is so good, that it would not improve with full frequency DSP/DRC. But a good speaker with a good power response is a nice place to start.

I would like to re-title this thread and argue that only State Of The Art Digital Room Correction should be used, for best result. Thankfully the knowledge of DSP/DRC has improved considerably and the best of the bunch, as of today a handful or so, is from the same cloth. Using algorithms based on psycho acoustic reasoning and frequency dependent window (FDW). What you essential is getting with SOTA DRC is room correction below the rooms transition frequency and speaker correction above.
 
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iansr

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godofwealth (nice nick) I have never seen a measurement of a speaker in combination with the room, that is so good, that it would not improve with full frequency DSP/DRC. But a good speaker with a good power response is a nice place to start.

I would like to re-title this thread and argue that only State Of The Art Digital Room Correction should be used, for best result. Thankfully the knowledge of DSP/DRC has improved considerably and the best of the bunch, as of today a handful or so, is from the same cloth. Using algorithms based on psycho acoustic reasoning and frequency dependent window (FDW). What you essential is getting with SOTA DRC is room correction below the rooms transition frequency and speaker correction above.
AND, if you also use it as an active crossover at the same time then you can get seamless crossovers with perfect time / phase correction, which are impossible to achieve with passive crossovers.
 

Hear Here

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Peter Walker once commented that using DSP to correct a loudspeaker’s sound was like looking at a Turner landscape using different colors. His preferred solution, of course, was to design a loudspeaker — the Quad electrostatics
I don't think room correction DSP had even been thought of in Peter Walker's day. He said that the ideal amp was a "straight wire with gain (or was it Stewart Hegeman), but he nevertheless included tone controls in his preamps. They could be bye-passed and this was his preferred setting. However, had he been around with DSP, I agree with you that he would have avoided it.

I would like to re-title this thread and argue that only State Of The Art Digital Room Correction should be used, for best result.

I'd prefer to look at the alternative methods of applying DSP. Certainly not as it so often is - by adding it to a full-range amplifier - to sort out the problem of room acoustics and make speaker setting up easier. These problems are made worse when subs are added and many people just can't get their complex arrangement properly set up and think that bunging DSP at the problem, it will go away.



Certainly frequency response can be flattened out using this method, but complex signal processing will do no favours to the top end - the area where it's unlikely to be required. However, these high frequencies can't not be processed, even though they may well not be adjusted. The only proper solution (that I suspect PW may have approved of) is to split the frequencies first, then send the bass to an amp with DSP, while the top end goes unmolested by DSP to its own amp. A modern active system such as Dutch & Dutch and a couple of Dynaudio speakers employ this arrangement. Soon most will, although there will be slow take up amongst the traditionalists who like a pile of boxes connected by a snake-pit of cables!
 

schlager

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Hear here, I don´t advocate using DSP/DRC over room acoustic treatment, they should go hand in hand. Why is the top end molested by DSP? It´s easy to correct the top end using nearfield measurements or alternatively in the SS with FDW measurement, as long as it is minimum phase.
Drawing subs into the equation, it has been well documented that using multiple subs, will even out room frequency response and seat to seat variation. Can you point to studies of the opposite?
 

Hear Here

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Why is the top end molested by DSP?
Top end frequencies generally don't need DSP, but you can't prevent the ENTIRE signal from going through the processor unless you cross over electronically before amplification - and this unavoidably requires 2 amps. Even with a DSP such as Dirac Live that can only ADJUST sub 500 Hza signal requires the top end to pass through.
 
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schlager

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So it´s the ADA that is troublesome? That problem was solved many years ago. Transparent DAC´s are easy to get hands on, also cheap ones.
Most speakers also expensive ones, are far from linear, compared even to the cheapest audio gear.
Let´s take a look at your Avantgarde Uno, I believe.

1669638148248.png
Not that bad, but could still need some top end eq. This will sound a bit bright. You don´t fix that with cable swapping or another amp. You tackle the problem by the root, fixing the FR with EQ.
Dirac Live have full FR EQ, probably not FIR above 500 hz. As I said only a handful of software does this correctly, Audiolense, Acourate, DRC Designer, Trinnov, comes to mind. They can be tweaked endlessly, to suit your speakers, room, listening distance and what not (taste of the day).
 

Mike Lavigne

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with the best 2 channel analog sources, even the very best digital 2 channel sources, in a fully executed mature system, in a room fully sorted out, dsp ends up as a handicap. you hear through it. it's in the way of the best sound, in the way of the the highest suspension of disbelief. the price you pay for the benefits of dsp are higher than the benefit.

but touching all those bases is not trivial. and dsp is a wonderful process for sources and systems optimized for it. or fixing issues.

and not claiming that dsp and 2 channel are not compatible; only that it's not the very most optimal execution of 2 channel recordings.

love my 9.3.6 Trinnov system in my HT room. Dolby Atmos and similar do deliver the goods. watched 'Top Gun; Maverick' on Thanksgiving with the family....it was awesome. horses for courses.

ideally in 2 channel you don't need to fix anything. every time you adc and dac the signal something is lost. or even change the resolution. nothing is free.
 
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schlager

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Mike, I beg to differ. Nobody has an ideally hifi situation, especially those relying on just using their ears. Just look at the impulse response from a analog setup (no DSP/DRC), not very pretty. Still in a very well treated room, almost all speakers are flawed in the frequency and time domain.
Subjective opinions don´t count for much (highest suspension of disbelief? what does that actually mean?), compared to what science actually tells us.
 

Mike Lavigne

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Mike, I beg to differ. Nobody has an ideally hifi situation, especially those relying on just using their ears. Just look at the impulse response from a analog setup (no DSP/DRC), not very pretty. Still in a very well treated room, almost all speakers are flawed in the frequency and time domain.
Subjective opinions don´t count for much (highest suspension of disbelief? what does that actually mean?), compared to what science actually tells us.
i guess we can simply not agree. i believe we can reach the analog ideal, but the truth won't be found on a graph. and perfect is not the objective. musically right is the objective. and there is more than one version, since different 'optimal' systems have different characters.

along my way i've taken measurements as a help; my speaker designer spent 2 days in my room. so those are useful data points. but graphs and numbers are not my truth. i respect that's not your perspective. i don't see whether you use analog sources or not. to me that is a big deal about perspective.
 
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iansr

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To make this less controversial lets put to one side analogue sources. So lets say your digital source is something like JRiver running on a dedicated PC and you are using JRiver’s own convolution engine to apply your combined crossover, time domain and room correction filters derived from AudioLense or Acourate. Absent the DSP filters you would still have had DA conversion, so I can only see upsides from using DSP, and those upsides are far from trivial.

A two channel system that doesn’t need fixing? Let me know when you come across one of those.
 

ecwl

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I think most people would agree that if there is a room acoustic issue, you're better off to treat it physically than to simply use DSP.

I mean, if there is a single resonance that's dominating the room and you have a way to treat the room to remove that resonance or you can move your listening seat to reduce that resonance, that's always better than using DSP.

I also think most people would agree that if your speaker has a truly undesirable frequency response and no matter how you toe-in/toe out or position your speakers, you can't get rid of the problem, you're always better off getting better speakers than to DSP your existing speakers.

Of course, I'm willing to hear people argue otherwise as to why they don't agree with the above statements.

Unfortunately, my living room has physical limitations that limit the amount of physical room acoustic treatments I can use (even if we can always argue that it's my choice not to turn my living room into a stereo store demo room).

So I have experimented extensively with DSP, ranging from parametric EQ to convolution filters with time-domain correction using Acourate. I can say that if you know what to listen for, in a high-resolution system, DSP always negatively affects the sound slightly, either in transient timing /accuracy when you're running time-domain correction, or in subtle loss of details or subtle loss of soundstage depth (likely due to subtle changes in accuracy in the lowest bits, e.g. bottom 22-24 bits). However, if like me, your system needs DSP desperately, inevitably, the gain from DSP, e.g. removing a 15dB peak at 50Hz, will almost always overwhelm the subtle loss of transparency. To me, DSP is always about compromises if you listen carefully but the vast of majority of the time, the benefits of DSP far outweighs the negatives, assuming you set things up optimally.

As to the original question of whether DSP belongs to a State of the Art system, I think that's a loaded question because I can easily cause more controversy by asking the following:
1) Do turntables belong to a State of the Art system?
2) Do stock cables belong to a State of the Art system?
3) Do computers belong to a State of the Art system?
4) Do untreated rooms belong to a State of the Art system?
I think all audio systems are about compromises and even State of the Art system has its own compromises, optimizing as many sonic traits as possible while accepting its limitations.

So to me, DSP has its place in a State of the Art system. And I agree with some people's comments that I think most systems will benefit from DSP, even in most stereo stores. That said, when people say they heard DSP and they hate it, my experience usually is that the DSP is suboptimally setup, not because DSP is a bad thing.

With all that said, I recently visited a friend's place and measured his listening position's frequency response and it is excellent. So he is very lucky that he probably won't benefit much from DSP. So these scenarios do exist.
 

morricab

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So it´s the ADA that is troublesome? That problem was solved many years ago. Transparent DAC´s are easy to get hands on, also cheap ones.
Most speakers also expensive ones, are far from linear, compared even to the cheapest audio gear.
Let´s take a look at your Avantgarde Uno, I believe.

View attachment 100917
Not that bad, but could still need some top end eq. This will sound a bit bright. You don´t fix that with cable swapping or another amp. You tackle the problem by the root, fixing the FR with EQ.
Dirac Live have full FR EQ, probably not FIR above 500 hz. As I said only a handful of software does this correctly, Audiolense, Acourate, DRC Designer, Trinnov, comes to mind. They can be tweaked endlessly, to suit your speakers, room, listening distance and what not (taste of the day).
If you think any old modern DAC will do then there is not much to discuss because very few here (myself included) will agree with you. If you just grab the high SN DAC from the ASR measurements then you will get something technically good measuring but listeners would disagree that it sounds very good.
 
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Hear Here

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Most speakers also expensive ones, are far from linear, compared even to the cheapest audio gear.
Let´s take a look at your Avantgarde Uno, I believe.

1669638148248.png

Not that bad, but could still need some top end eq. This will sound a bit bright. You don´t fix that with cable swapping or another amp. You tackle the problem by the root, fixing the FR with EQ.
Dirac Live have full FR EQ, probably not FIR above 500 hz. As I said only a handful of software does this correctly, Audiolense, Acourate, DRC Designer, Trinnov, comes to mind. They can be tweaked endlessly, to suit your speakers, room, listening distance and what not (taste of the day).


The character of sound delivered by different speakers is what makes one choose that particular speaker. If all speakers had their frequency response flattened to a straight line, wouldn't that make them all sound alike? That would be most unwelcome, I'm sure you'll agree. The fact that the Uno graph you illustrated was so highly praised by Stereophile in 2000, resulted in the sound described by the reviewer as:

The illusion of "liveness" in reproduced sound is a delicate perceptual phenomenon dependent on the source material, equipment, room, and time of day, as well as the listener's mood and expectations. I have experienced this illusion in the past with some speakers in my system, but only rarely and in a fleeting manner. With the Avantgarde Uno, it was a frequent occurrence, and persisted for longer periods before something about the sound acted as a reminder that I was listening to a recording.

The speaker was voiced by expert listeners and not by a technician and this led to its selection as “Speaker of the Year” by the Stereophile editorial staff.

The reviewer, Robert Deutsch was sufficiently thrilled by the Uno that he purchased Unos for his own system and also led me to purchase them in 2002. It is probably because the response is not dead flat that we love the sound from these horn speakers and I'd never want to tamper with the higher frequencies - or they may end up sounding as predictable and sighttly "dead" as so many systems are!

My point is that speakers are designed to sound as much like a live performance as possible and to take away none of the excitement of hearing music live. DSP can kill this excitement factor, or at least reduce it.

Bass is a different matter and, if all else has failed (an indication perhaps of not enough effort put into setting up), then PERHAPS DSP could be resorted to but ONLY the bass frequencies should be sent to an amplifier that includes a DSP processor - not the top end. Later Avantgarde systems (designated XD) do have DSP in their sub amps, but of course the mid and top horns receive the unmolested signal.

Dirac Live is available in 2 versions (perhaps more) but the version I have adjusts only sub 500 Hz, but nevertheless the top end is reduced in its lifelike excitement factor – easily demonstrated – so I keep it disengaged in my own system.
 
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iansr

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“If all speakers had their frequency response flattened to a straight line, wouldn't that make them all sound alike?”

I think you need to do a bit of reading. And referencing a magazine review as evidence - seriously ?
 

schlager

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Hera here, using Stereophile as a guide won´t necessarily yield good results. I only use them for the measurements. The power response for such horn systems are often pretty bad, due to design. I know I used to have one. The do sound great correctly implemented, but it´s not SOTA.
A very important point on using DRC, is that the left and right speaker will have the same frequency response in the SS. That will rarely be the case without DSP/DRC.
 

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