Does DSP belong in State of the Art Systems?

Brucemck2 said:

I’d love to see Taiko or MSB or similar take on building hard-core audiophile DSP systems. My experience is that part of what we attribute to “DSP” is less about digital processing than it is about less than state of the art internal power supplies, clocks, jitter reduction, etc. etc. in the products we are using to hear and evaluate DSP processing.

One experience brought this home to me. I was using a DEQX to provide digital crossover functionality for a custom built two way line array. This was only crossover functionality and not room correction. The DEQX did some “magical” things for the sonics, but it was also “taking away” some of the magic of the (simple, purist) analog crossover. In the end I still preferred the analog crossover most of the time. I then heavily modified the DEQX with better internal power supplies, better internal grounding schemes, high-end input and output transformers, better clocks, better shielding, etc. etc. etc. Following those mods the DEQX was better in all ways than the analog setup. What I had been attributing to “DSP” was more a result of the types of things audiophiles obsess over and not “the math manipulation”. My recent experiences with the SwitchX and AppleTV-X products were similar - the sonics coming from “digital” products improved materially with upgrades to their “non-math” components.

I suspect that if Taiko or MSB or Wadax or the like took this on we’d be having a different discussion about the drawbacks of DSP in high end two channel systems. (And if anyone reading this wants to take on a Trinnov upgrade project DM me!)

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Do you have anything further to add as to the DEQX part, mods, etc?

Holmz said:

Do you have anything further to add as to the DEQX part, mods, etc?

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Not beyond the SwitchX and AppleTV-X line, which are terrific.

It’s been too long since modding anything and the firm I relied upon for my DEQX mods (Steve Nugent with Empirical Audio) has moved on.

(If anyone has someone they have found reliable please let me know. It’s art and science.)

sigbergaudio said:

DSP for room correction is difficult to get right, and most automatic systems fail to do so well. The best approach is to apply it sparingly and mostly to the bass.

While I have exclusively active, digital crossover speakers, none of the systems have active room correction. Any applied DSP is manually applied below 100-150hz only. Start with good speakers and an acoustically decent room, and that is all you need.

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I 100% agree with your final sentence as do many of my audiophile/music loving friends. Several of us have either Von Schweikert speakers with superb off axis dispersion or Legacy Signature IIIs with their rear ambiance tweeter. I have both. Both rooms have excellent audio qualities. People can lie down, stand up, be located at either end of the room and experience great sonics. There is a sweeter spot in the center of my custom listening room but in my living room with the Signature IIIs there is no apparent sweet spot, it's all sweet (lucky room characteristics).

I know that Legacy uses DSP extensively. I've heard some good demonstrations. It's not a matter of active or passive speakers. While I do not use DSP, my Von Schweikerts do have extensive analog controls on the subwoofer bass which DSP could address (or on smaller speakers, subs). Many audiophiles don't concern themselves with even room dispersion as they prefer a center specific seat or two. It wasn't for me (I was glad to sell my old Legacy Focus speakers).

SeagoatLeo said:

I 100% agree with your final sentence as do many of my audiophile/music loving friends. Several of us have either Von Schweikert speakers with superb off axis dispersion or Legacy Signature IIIs with their rear ambiance tweeter. I have both. Both rooms have excellent audio qualities. People can lie down, stand up, be located at either end of the room and experience great sonics. There is a sweeter spot in the center of my custom listening room but in my living room with the Signature IIIs there is no apparent sweet spot, it's all sweet (lucky room characteristics).

I know that Legacy uses DSP extensively. I've heard some good demonstrations. It's not a matter of active or passive speakers. While I do not use DSP, my Von Schweikerts do have extensive analog controls on the subwoofer bass which DSP could address (or on smaller speakers, subs). Many audiophiles don't concern themselves with even room dispersion as they prefer a center specific seat or two. It wasn't for me (I was glad to sell my old Legacy Focus speakers).

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Interesting that you describe the sound from your box speakers as comparable with how I visualise omni-directional ones. You say there is virtually no sweet spot, yet the tweeters of your speakers face forward - a direction that would suggest a serious loss of high frequencies when sitting at large angles from the speakers.

I'm intrigued as omnis should be the ideal type of speaker in my own virtually semi-circular room with speakers placed mid-room and the dining and kitchen areas behind the speakers. Yet, when I visit big-brand omni dealers, I get the "omni" sound rather as you describe, but the imaging is poor compared with the highly directional horns that I currently use. Despite the horns' small sweet spot, I'd trade their astonishing imaging for the better sound in other parts of the room, particularly, as I suspect, room treatment would need to be far more comprehensive with any type other than horns. Electrostatics are not good in my room and, although I'm not had any on home-demo, I doubt I'd be happy with omnis, at least not from my usual listening position.

'm curious as I'm slightly surprised by your own experience with box speakers with all drivers facing forward , although I note that Von Schweikert feature secondary tweeters in their real panels. Unfortunately I don't think there's any Von Schweikert representation in the UK, so a demo is likely impossible.

Hear Here said:

Interesting that you describe the sound from your box speakers as comparable with how I visualise omni-directional ones. You say there is virtually no sweet spot, yet the tweeters of your speakers face forward - a direction that would suggest a serious loss of high frequencies when sitting at large angles from the speakers.

I'm intrigued as omnis should be the ideal type of speaker in my own virtually semi-circular room with speakers placed mid-room and the dining and kitchen areas behind the speakers. Yet, when I visit big-brand omni dealers, I get the "omni" sound rather as you describe, but the imaging is poor compared with the highly directional horns that I currently use. Despite the horns' small sweet spot, I'd trade their astonishing imaging for the better sound in other parts of the room, particularly, as I suspect, room treatment would need to be far more comprehensive with any type other than horns. Electrostatics are not good in my room and, although I'm not had any on home-demo, I doubt I'd be happy with omnis, at least not from my usual listening position.

'm curious as I'm slightly surprised by your own experience with box speakers with all drivers facing forward , although I note that Von Schweikert feature secondary tweeters in their real panels. Unfortunately I don't think there's any Von Schweikert representation in the UK, so a demo is likely impossible.

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Unfortunate that you cannot experience the Von Schweikert speaker. The rear fully adjustable ribbon super tweeters (as are the front units) permit infinite settings for the desired ambiance in a room. The imaging of the VS speaker is rock solid and unbelievably accurate in recreating the venue image into the microphone(s). I've had box speakers that are great for a central image as well as a few Martin Logan stats that were really tight in seating. Many other great dispersion speakers fail to image well and omni's aren't for me. Panel speakers are also commonly poor imagers. Even the expensive Alsyvox speakers imaging was too large for me despite the beautiful sound. I remember my first introduction to Magnapans with instruments and voices 5 to 8 foot wide.

I've heard the VS Ultra 9 and 11 in $1+ million audio rooms with my LPs and CD sounding as if the performers were directly in front of me. In my own system, I hear similar imaging. It's more dependent on the recording engineering right now. If it's close miked or lacking in substantial reverb, instruments and voices can sound as if they are performing in front of me, to the left or right, sometimes outside the speakers (often out of phase then). One can feel the instrument resonating as well as visualize it/them outside the speakers. My wife and I love it. I'm still have some improvements to cabling and older equipment which will elevate the experience more. I am shocked how good many LPs and CDs I was gave up for their poor sonics (usually overly distant and/or drenched in reverb) can sound musically satisfying and sonically elevated (I have 61,100 LPs/CDs/78s/R2R). Early stereo recordings often tend to be delegated to left and right channels with little center fill (jazz and stereo showcase recordings/ping ponging).

I've heard too many horn speakers that are unsuitable for home use. They also have some extraordinary properties such as a recreation of the body of the music (often with coloration) but the best were huge made for auditorium size spaces (and are super efficient).

SeagoatLeo said:

the best were huge made for auditorium size spaces

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Unless they aren't.

Hear Here said:

That's absolutely right. Few high end systems include "room correction DSP" because they are likely to be feeding similarly high end speakers. The better the system (provided it's set up properly in a sympathetically furnished room), the less the need for DSP.

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Hook, line and sinker .

Hear Here said:

Interesting that you describe the sound from your box speakers as comparable with how I visualise omni-directional ones. You say there is virtually no sweet spot, yet the tweeters of your speakers face forward - a direction that would suggest a serious loss of high frequencies when sitting at large angles from the speakers.

I'm intrigued as omnis should be the ideal type of speaker in my own virtually semi-circular room with speakers placed mid-room and the dining and kitchen areas behind the speakers. Yet, when I visit big-brand omni dealers, I get the "omni" sound rather as you describe, but the imaging is poor compared with the highly directional horns that I currently use. Despite the horns' small sweet spot, I'd trade their astonishing imaging for the better sound in other parts of the room, particularly, as I suspect, room treatment would need to be far more comprehensive with any type other than horns. Electrostatics are not good in my room and, although I'm not had any on home-demo, I doubt I'd be happy with omnis, at least not from my usual listening position.

'm curious as I'm slightly surprised by your own experience with box speakers with all drivers facing forward , although I note that Von Schweikert feature secondary tweeters in their real panels. Unfortunately I don't think there's any Von Schweikert representation in the UK, so a demo is likely impossible.

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The reason you'll find some tweeters facing the wrong way, is an attempt to delay their wavefront so much they it's not obtrusively out of phase with the rest.

Phase is something few hifi speakers address.

2nd / 3rd / 4th order crossovers used make for large phase shifts.

This often results in a sound that is not natural for the brain to interpret.
Ever found speakers sound fatiguing?

The quote "A changing phase is a changing time" comes to mind.

If you can, get to listen to some well implemented Multi Entry Horns that are phase coherent from below 100Hz to well over 10000Hz.

Also horn systems with large distances between the drivers are not interpreted as the sound coming from a single source.
The frequencies are spread over distance and time!
This can be mitigated to a certain extent by sitting a farther away from them.
They may sound impressive on some materials but often fall apart and sound compressed on more complex music.

Users can tend to avoid challenging music and end up listening to simpler close mic 'd music and jazz which is easier for these systems to handle and sound good.
Ever wondered why they play plinky plonky stuff at demos?

Try them on some ACDC and see how they get on.

Great post Steve. I’ve been to Munich and I couldn’t believe it when I first saw the distance between the high frequency and the mid horns on some of the stupid money horn systems being demoed. Unfortunately many so called audiophiles are completely unaware of the significance of CTC spacing. Phase, lobing, comb filtering anyone? If it costs > €100k it’s got to be well designed, right ? .

iansr said:

Hook, line and sinker .

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iansr said:

Great post Steve. I’ve been to Munich and I couldn’t believe it when I first saw the distance between the high frequency and the mid horns on some of the stupid money horn systems being demoed. Unfortunately many so called audiophiles are completely unaware of the significance of CTC spacing. Phase, lobing, comb filtering anyone? If it costs > €100k it’s got to be well designed, right ? .

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Yep, imagine companies that mount drivers in discrete cabinets creating added CtC gaps and edge diffraction that they advertise as a feature for adjustability. What's that about a sucker? ;-)

Multiway said:

The reason you'll find some tweeters facing the wrong way, is an attempt to delay their wavefront so much they it's not obtrusively out of phase with the rest.

Phase is something few hifi speakers address.

2nd / 3rd / 4th order crossovers used make for large phase shifts.

This often results in a sound that is not natural for the brain to interpret.
Ever found speakers sound fatiguing?

The quote "A changing phase is a changing time" comes to mind.

If you can, get to listen to some well implemented Multi Entry Horns that are phase coherent from below 100Hz to well over 10000Hz.

Also horn systems with large distances between the drivers are not interpreted as the sound coming from a single source.
The frequencies are spread over distance and time!
This can be mitigated to a certain extent by sitting a farther away from them.
They may sound impressive on some materials but often fall apart and sound compressed on more complex music.

Users can tend to avoid challenging music and end up listening to simpler close mic 'd music and jazz which is easier for these systems to handle and sound good.
Ever wondered why they play plinky plonky stuff at demos?

Try them on some ACDC and see how they get on.

Click to expand...

I contend that box dynamic driver speakers can have fantastic sound with all genres of music. I have 61,100 LPs, CDs, 78s and R2R tapes. I play Live at Leeds, Mahler symphonies and Count Basie big band music as loud as I desire. Horns maybe more impressive. I still receive very impressive, fulfilling sound. I can also play vocals, simple instrumentals were fabulous sound as well. My speakers are expensive but they are not any more than other contending big horn speakers (Von Schweikert VR9 SE Mk2). Even my best friend's VS VR35 exports sound fabulous with all genres of music. Contrariwise, I've experienced too many horn systems which sound discombobulated and are in the $200K range in $500+K systems. My Legacy Signature IIIs of which I own 2 pairs, one for TV and the other for my living room can play all genres of music beautifully lacking mostly resolution with lower powered tube amps, just not flea powered amps. I happen to like the Volti series of speakers but I want better dispersion which is why I own the speakers I do.

I suspect your indictment of horns is similar to mine. Those large multi-horn speakers sound best at a distance. I've experienced large format music such as symphonies, opera and heavy metal on them in moderate size rooms and they are impressive. They fell apart attempting to play small ensembles and simple vocals-stretching the sound of each and not being cohesive. Those same vocal, guitar and bass played on my simple Signature IIIs had the owner of the BIG system dumbfounded with it's sweetness, clarity and coherence.

Hear Here said:

Interesting that you describe the sound from your box speakers as comparable with how I visualise omni-directional ones. You say there is virtually no sweet spot, yet the tweeters of your speakers face forward - a direction that would suggest a serious loss of high frequencies when sitting at large angles from the speakers.

I'm intrigued as omnis should be the ideal type of speaker in my own virtually semi-circular room with speakers placed mid-room and the dining and kitchen areas behind the speakers. Yet, when I visit big-brand omni dealers, I get the "omni" sound rather as you describe, but the imaging is poor compared with the highly directional horns that I currently use. Despite the horns' small sweet spot, I'd trade their astonishing imaging for the better sound in other parts of the room, particularly, as I suspect, room treatment would need to be far more comprehensive with any type other than horns. Electrostatics are not good in my room and, although I'm not had any on home-demo, I doubt I'd be happy with omnis, at least not from my usual listening position.

'm curious as I'm slightly surprised by your own experience with box speakers with all drivers facing forward , although I note that Von Schweikert feature secondary tweeters in their real panels. Unfortunately I don't think there's any Von Schweikert representation in the UK, so a demo is likely impossible.

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I'll jump in here for information purposes and perhaps a bit of tempered promotion.

Albert Von Schweikert developed Von Schweikert's Acoustic Inverse Replication (AIR) system initially in the VR-series and now in every speaker that has followed. Albert believed that for proper replication of music in the home, a loudspeaker's function was to decode what the microphone encodes. Naturally, this included ambient information.

All drivers are housed in a single-phase, aligned cabinet, with the rear ambient driver(s) precisely adjustable for output and perfectly integrated into the wave launch of the forward-facing drivers. He also believed in a wide and linear off-axis response. For listeners who have experienced the system tonally, they are stunned that, wherever they are in the room, including behind the speakers, the tonal balance sounds nearly identical in the sweet spot as it does when walking around the room in short distances, where you are in the soundscape changes, but not the top-to-bottom balance.

A condensed version of Albert's white papers on the subject can be found on the VS website here.


P.S. Regarding the topic of the thread, no DSP is used in the VS system, including for bass management. However, time, phase, and other parameters can be adjusted with remarkable precision using it, and the results can be surprisingly good.

Next discussion?
State of the art DSP controlled phase coherent Multi Entry (Synergy) Horns + suitable subs

Very interesting information about Albert’s AIR system. A friend just bought a pair. I can’t wait to hear them. I own Legacy Audio Valors with the Wavelet processor. His systems have had the ability to accomplish what the AIR systems can accomplish for a while now.

I believe many speaker craftsmen will build in similar systems. I think we’ve just scratched the surface.

Ultimately we may be able to tell our speakers systems to dial in the acoustics of venues. We may be able to match the acoustics of the venue to the recording someday.

Steve Rowan said:

Very interesting information about Albert’s AIR system. A friend just bought a pair. I can’t wait to hear them. I own Legacy Audio Valors with the Wavelet processor. His systems have had the ability to accomplish what the AIR systems can accomplish for a while now.

I believe many speaker craftsmen will build in similar systems. I think we’ve just scratched the surface.

Ultimately we may be able to tell our speakers systems to dial in the acoustics of venues. We may be able to match the acoustics of the venue to the recording someday.

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I suspect the Ultra 7 photo lacks the Foundation Hybrid Bass System. It is the passive version of the speaker. The active version has a Foundation power amp. Unlike other active DSP designs, the full range of the signal passes entirely through the analog crossover network. This allows the tonal characteristics of the customer's preferred power amplifier without compromise yet offers the increased dynamics and precise adjustment of your in-room bass response.

Seagoat, you are correct, the image shown does not include the Foundation bass amplifier and represents a non-active bass version. All Ultra 7s leaving the factory these days are equipped with the Foundation solution.
Foundation uses no DSP to perform its role, and as you mentioned, the amplifier driving the mid/high frequencies determines the overall sonic signature.

Steve, Legacy's latest design work with the Wavelet looks quite sophisticated, and I am sure it sounds very good. Before joining Von Schweikert, my firm designed advanced line arrays for the home that used the excellent DEQX DSP crossover/processor. Typically, we utilized up to 12 amplification channels and achieved outstanding results. Overall, when used appropriately, DSP can be very effective, accomplishing remarkable things in the time and spatial domains.

The Bach processor is perhaps the most sophisticated example in the audiophile domain. I've also heard that Trinnov is doing incredible DSP work in their home theater processors. In pro audio, Meyer Sound has developed systems that can manipulate acoustic space in any venue, regardless of size!

At VSA, we have a future project for a fully powered monitor, and we may consider using DSP on that one. In the meantime, Albert's principles for recreating a natural aprotrayal of acoustic spaces continue to stand the test of time using non-DSP methods. As we know, exceptional sound reproduction that moves the soul can be achieved in various ways.

Onward.............

PS The array shown below was a three-way system with the subwoofers mounted into the floor

That’s what Legacy does to. I use the XLR inputs to connect Wavelet to my preamp. Then after time alignment etc. The outputs then go to my amps and speakers.