Digital Audio with Soundstage Depth? Question for Digital Gurus

[Al M.]

My experience is that DACs featuring sharp digital reconstruction filtering (meaning; most) typically produce a wide but shallow soundstage.

These days sharp digital reconstruction filtering is usually avoided by upsampling. This allows for the use of a much shallower slope of filtering. My DAC upsamples CD to 176.4 kHz (4 x sampling rate), and filters from there.

 

[opus112]

If you look at the insides of a typical digital upsampling (oversampling) filter you'll find the steep filter is still there. It'll be the first X2 stage which requires a longish ( > 100 tap) filter due to the narrow width of the transition band.

The filter that's able to be much shallower is the analog one (anti-imaging filter) - precisely because the heavy lifting's being done by the digital filter.

 

[jkeny]

Agree completely about the low level microdetail/cues being the key to the illusion of soundstage depth. Also agree that the biggest hindrance is CM, usually RF, noise and this can be checked using a isolation transformer on the output of the DAC. I gave an example of this on this post
Also agree that NOS seems to deliver this far better than SD DACs but not sure how much of this 2Dness is due to the upsampling filters & how much to anti-image filter? I've played around with the PCM1794 DAC ala DDDAC with no upsampling digital filter but it still uses an anti-imaging output filter, AFAIK. The sound was greatly improved but not as 3D as a Soekris DAC in NOS mode (I'm not sure if all upsampling is disabled in it's FPGA?).

 

[Speedskater]

Thinking more about the Telarc recording soundstage. All Telarc recordings use a minimalist microphone technique that creates a realistic soundstage. Many other labels use multi-(mono)-miked pan-potted techniques that create an artificial soundstage.

Siegfried Linkwitz often writes on this subject:
http://www.linkwitzlab.com/The_Magic/The_Magic.htm

 

[jkeny]

Thinking more about the Telarc recording soundstage. All Telarc recordings use a minimalist microphone technique that creates a realistic soundstage. Many other labels use multi-(mono)-miked pan-potted techniques that create an artificial soundstage.

Siegfried Linkwitz often writes on this subject:
http://www.linkwitzlab.com/The_Magic/The_Magic.htm

Yea, Linkwitz says some interesting things like

"Also, when farther away from the speakers and deep into the reverberant field in the listening room, the tonality does not change. The room is easily forgotten.

The magic is difficult to describe in pictures or words but is recognized within 30 seconds when heard. It usually elicits a big smile or even laughter from the listener. Naive listeners, audiophiles and professionals alike recognize the naturalness of presentation. On many recordings it is 3D in front of the listener and resembles a concert experience. When watching movies on a screen between the speakers, on-screen dialogue and sounds are clearly separated from those off-screen. Center and side speakers are not missed as the two speakers alone render a smooth continuum."

But his focus is speakers & rooms. I believe that when the digital playback system is delivering these subtle details correctly, the room & speakers become secondary i.e the illusion works irrespective of room treatment & speakers (given non-deviant performance for both). In other words, speakers & rooms may deepen the sense of illusion but will not be able to create it if the source isn't delivering. To put it another way, ordinary rooms & speakers will deliver but it takes a good bit of effort to get the digital playback electronics performing sufficiently well to deliver good soundstage depth.

The ability of analogue systems to render this "smooth continuum" is well known & something digital mostly strives to achieve

 

[microstrip]

Yea, Linkwitz says some interesting things like

But his focus is speakers & rooms. I believe that when the digital playback system is delivering these subtle details correctly, the room & speakers become secondary i.e the illusion works irrespective of room treatment & speakers (given non-deviant performance for both). In other words, speakers & rooms may deepen the sense of illusion but will not be able to create it if the source isn't delivering. To put it another way, ordinary rooms & speakers will deliver but it takes a good bit of effort to get the digital playback electronics performing sufficiently well to deliver good soundstage depth

We have to separate soundstage depth from soundstage layering. Many systems have great depth - everything happens behind the speaker plane and even behind the front wall, but no capability of recreating front to back space between instruments and around instruments. They show spaciousness, but lack spatial detail. The way the whole system, including source, handles detail and microdynamics has great importance in this aspect.

 

[Speedskater]

Are you suggesting that an analog (LP) playback system is more accurate than digital?
Not a chance.

 

[bonzo75]

Are you suggesting that an analog (LP) playback system is more accurate than digital?
Not a chance.

It's more real

 

[Speedskater]

It's more real

Does more real mean more accurate?
Or enjoyable added euphonic colorization?

 

[bonzo75]

Does more real mean more accurate?
Or enjoyable euphonic colorization?

Neither. If you hang out at barbican, wigmore hall, st Martin's in the field, etc, accurate and euphonic coloration become meaningless words to be bandied about on audiophile forums. I am happy with the Lampi, because they sound real, would like to go vinyl, and rest of digital is a waste of money, convenience aside

 

[jkeny]

We have to separate soundstage depth from soundstage layering. Many systems have great depth - everything happens behind the speaker plane and even behind the front wall, but no capability of recreating front to back space between instruments and around instruments. They show spaciousness, but lack spatial detail. The way the whole system, including source, handles detail and microdynamics has great importance in this aspect.

I haven't come across soundstage depth without layering, AFAIR - I'll keep an ear out for such.

 

[jkeny]

Are you suggesting that an analog (LP) playback system is more accurate than digital?
Not a chance.

Does more real mean more accurate?
Or enjoyable added euphonic colorization?

You might just be missing something here if you think about it - the psychoacoustics of hearing.
I can only surmise what is at the heart of this difference between analogue & digital is perhaps noise &/or distortion that varies with the low level digital signal, hence masking it. Analogue, having a higher noise floor but one that doesn't vary with the same characteristics when handling low level signals is more physchoacoustically benign & allows finer details to be perceived.
Or maybe fluctuating noise at very low levels are more important than we think?
Or.......

Those who are wedded to their measurements meters will never find the answer to this unless they begin to study the way the illusion is created by the brain & the factors that are crucial for this to happen. Only then will "accuracy" have any real significance to the listener. Or to put it another way - start measuring "accuracy" where it counts by understanding the mechanism of this auditory illusion.

 

[LL21]

I haven't come across soundstage depth without layering, AFAIR - I'll keep an ear out for such.

In my limited experience, i think about soundstage depth, layering as follows:

- in certain recordings, there may be very strong cues in the recording from the BACK of the orchestra which then create that back wall on playback
- but upon further refinement/reduction of noise/grunge/distortion, the system can also differentiate in much smaller spacial cues from instruments in the middle of the orchestra...things that can get lost "in the middle" where the playback has first violin front and center, then a big kettle drum in the way back...and then loads of instruments 'in the middle'
- when that distortion drops, the system starts to resolve/show those subtle cues from the middle of the orchestra and layering begins; violins, violas, cellos start to pull apart from each other; trumpets blaring with french horns start to pull away from each other musically where one can hear each group
- simultaneous with this are very, very clear "musical lines" that carry on in parallel with other musical lines...and suddenly it becomes easy to follow one line of music while other instruments are clearly playing another line of music...and if you wish to switch from one line to the other, you can

i experienced and learned a bit about this first in HK with an all-out assault on grunge, noise, power, emi/rfi...and it was all on tracks i brought myself. I then experienced it again at Audiocrack's place, and then again in HK. That's my own personal experience and how i can get put it into words. hope that makes [some] sense.

 

[jkeny]

Are you suggesting that an analog (LP) playback system is more accurate than digital?
Not a chance.

In my limited experience, i think about soundstage depth, layering as follows:

- in certain recordings, there may be very strong cues in the recording from the BACK of the orchestra which then create that back wall on playback
- but upon further refinement/reduction of noise/grunge/distortion, the system can also differentiate in much smaller spacial cues from instruments in the middle of the orchestra...things that can get lost "in the middle" where the playback has first violin front and center, then a big kettle drum in the way back...and then loads of instruments 'in the middle'
- when that distortion drops, the system starts to resolve/show those subtle cues from the middle of the orchestra and layering begins; simultaneous with this are very, very clear musical lines that carry on in parallel with other musical lines...and suddenly it becomes easy to follow one line of music while other instruments are clearly playing another line of music...and if you wish to switch from one line to the other, you can

That's my own personal experience and how i can get put it into words. hope that makes [some] sense.

Yes I understand that & it is my experience too but I find that once soundstage depth appears then this layering is there unless the soundstage depth is crudely created by manipulation in the recording studio i.e a false soundstage

 

[bonzo75]

Some soundstages are plain wide, some are forward, and some are back of the speakers with layering that shows the depth from the first violin and strings to the tympani. Some show all.

Where I love the Lampi is replace a digital component with out and it kicks the soundstage backwards, forwards, and sideways.

The restored Apogees I fell in love with coz they created a stage behind, layered, tympani in the deep with impact, and then the sound coming forwards from the vertical wall, just like from the stage. The sideways soundstage requires sufficient width between the panels for them to disappear

 

[Ken Newton]

As I think a bit more about the question of perceived playback soundstage size and shape, I think that it is largely determined by the ratio of direct versus ambient sound cues, just as it is for a live soundstage. For live sound, those cues include arrival amplitude differences, arrival time differences and arrival directional differences. 2-channel stereo sound is lacking in accurate arrival direction differences, but can capture accurate arrival amplitude and time differences. This suggests that for 2-channel stereo, differences in reproduced soundstage size and shape are mostly do to how the reproduction system resolves amplitude and time for ambient arrival cues versus direct arrival cues.

The above notion reflects exactly how typical digital playback sounds to me. It sounds direct arrival dominant and relatively lacking in ambient sound cues. The resulting effect of reproduction over-favoring the direct sound cues is a wide and upfront perceived soundstage, sort of like one is sitting on stage with the performers and too close to the instruments. Some playback equipment excels in resolving the ambient sound cues on a recording. The better resolved the recorded ambient sound is, the deeper the soundstage illusion appears to be. At least, that how it seems to me.

 

[jkeny]

As I think a bit more about the question of perceived playback soundstage size and shape, I think that it is largely determined by the ratio of direct versus ambient sound cues, just as it is for a live soundstage. For live sound, those cues include arrival amplitude differences, arrival time differences and arrival directional differences. 2-channel stereo sound is lacking in accurate arrival direction differences, but can capture accurate arrival amplitude and time differences. This suggests that for 2-channel stereo, differences in reproduced soundstage size and shape are mostly do to how the reproduction system resolves amplitude and time for ambient arrival cues versus direct arrival cues.

Yes, Ken although I'm not so sure that directional differences are all that important when listening to live music in a hall for instance. Griesinger has done research into this & developed the LOC method of evaluating what he calls envelopment which seems to correlate to perception better than previous methods. It is based on the timing &energy of the direct sound to the reflected sound but not on direction AFAIR.

The above notion reflects exactly how typical digital playback sounds to me. It sounds direct arrival dominant and relatively lacking in ambient sound cues. The resulting effect of reproduction over-favoring the direct sound cues is a wide and upfront perceived soundstage, sort of like one is sitting on stage with the performers and too close to the instruments. Some playback equipment excels in resolving the ambient sound cues on a recording. The better resolved the recorded ambient sound is, the deeper the soundstage illusion appears to be. At least, that how it seems to me.

Indeed & these ambient sound cues tend to low level & low frequency so maybe those who make claims for the accuracy of digital playback could plot the real "accuracy" of these characteristics under dynamic conditions i.e while also concurrently reproducing dynamic signals at higher volume levels?

 

[Folsom]

I had a Thorens TD-124 and SME-3009 arm when they were the new things.
At the classical music radio stations, we played most of the music on turntables.


Yes there are often mastering differences. Yes some tube gear adds euphonic coloration of it's own. But as for soundstage differences the cutter and phono cartridge are mostly responsible.


What about the Telarc direct-to-disc album (now that was a lot of work)? What about all the Telarc LP albums that I still have?

Where you involved with recording them?

I'm jelly you had a Thorens, my turntable now is apparently not nearly as good according to another thread here.

My point really is that the added noise and such from vinyl is actually somewhat moot. I can get any kind of sound from vinyl, be it a sterile Telarc Digital (not all of them are, but some are, and they don't sound bad), or a voluptuous dosing of character. It just isn't a good argument for me as towards the explanation of perceiving a soundstage. I think the difference between electrolytic, film caps, and quality audiophile film caps on the input/output of an preamp, amplifier, or phono preamp make a larger difference than vinyl's extra offerings. (And they do measure better)

Much less money can be put into vinyl to achieve what you can get out of digital. You know what I think a truly good DAC is? MSB's higher end models. I'd be fine with using a $10 DAC from China if it sounded as good, but they just don't. I would never recommend digital as the cheaper option, ever, to achieve sound that appears real to you. It's about convenience and that factor is big enough that I'd never blame anyone for going digital.

Are you suggesting that an analog (LP) playback system is more accurate than digital?
Not a chance.

Define accurate, because distortion figures and vinyl noise are not necessarily useful for a comparison. Only the music itself really is important; especially considering we basically can't hear distortion until it's at astronomical amounts and that we have selective hearing.

 

[Al M.]

If you look at the insides of a typical digital upsampling (oversampling) filter you'll find the steep filter is still there. It'll be the first X2 stage which requires a longish ( > 100 tap) filter due to the narrow width of the transition band.

The filter that's able to be much shallower is the analog one (anti-imaging filter) - precisely because the heavy lifting's being done by the digital filter.

Thanks for the technical explanation and correction. This does not take away the fact that you don't need a NOS DAC for great soundstage depth and layering. Anyone who does not believe me: come listen to my system. The audible evidence will speak for itself.

 

[Al M.]

I haven't come across soundstage depth without layering, AFAIR - I'll keep an ear out for such.

That is correct in my view. An image far behind the speakers but without any front-to-back information is simply a recessed image. This has nothing to do with depth.

And by the way, the spaciousness creating a recessed image can simply be an artifact of the room acoustics, and may have nothing to do with system capabilities or lack thereof. Alas I have painful knowledge of this, since I have fought for many months against too recessed images in my room, until I got my ASC window plugs. And even then, further tuning was needed, involving carpets, among others.