DSD to PCM Conversion A/B Test Results

[microstrip]

If DSD is better, why use PCM at all?

Because many professionals object to DSD - either because of theoretical reasons, aspects related to mixing and mastering or simply sound preference.

The subject is extensively debated in professional audio forums.

 

[Rexp]

Because many professionals object to DSD - either because of theoretical reasons, aspects related to mixing and mastering or simply sound preference.

The subject is extensively debated in professional audio forums.

I was asking Lee for his personal view, as I'm interested to know why he does PCM recordings when he clearly prefers DSD....

 

[Lee]

If DSD is better, why use PCM at all?

Because not everything is available in DSD. Many studios are oriented to ProTools which is mostly PCM.

 

[Lee]

I was asking Lee for his personal view, as I'm interested to know why he does PCM recordings when he clearly prefers DSD....

That’s a different question. Because editing is easier in PCM and some of our musicians have DVD-Audio players.

 

[Believe High Fidelity]

I think there are a few issues with the test and discussion as others have noted:

1. It is not possible to record at DSD512. The test track is 8x upsampled DSD64, and then downsampled

This is another reason for a second test. I am going to convert the file DSD64 (without the upsampling) to see if this had an effect.

 

[dminches]

I saw an interview with Bernie Grundman about all this. He thinks that recording to DSD is a mistake since the conversion to PCM for editing is "destructive" with respect to sound quality.

 

[Carlos269]

I saw an interview with Bernie Grundman about all this. He thinks that recording to DSD is a mistake since the conversion to PCM for editing is "destructive" with respect to sound quality.

My Sadie 5 DSD8 DAW allows for editing in DSD-wide. So there are exceptions to this.

 

[Ian B]

My Sadie 5 DSD8 DAW allows for editing in DSD-wide. So there are exceptions to this.

The Sonoma system is also DSD-wide. It's only Pyramix that converts to PCM, and there only at the actual regions that are being edited, which could be so miniscule as to be inaudible.

One only needs PCM conversion if they need to significant DSP or mix multiple channels in the DAW.

 

[Ian B]

In fact, current modern recording systems are much more complex than people imagine - a DXD recoding does not mean that the recording was carried in pure PCM 382/24 - such thing does not exist!

I can assure you, it very much does and there are many examples.

 

[microstrip]

I can assure you, it very much does and there are many examples.

Thanks. Can you describe the hardware being used for such recordings and a few examples of such recordings? As far as I have read ADCs being used in audio do not convert analog signals directly to PCM 382/24 - the ADCs are delta sigma and do not have 24 bit resolution. But I have not followed the subject for the last few years.

 

[Ian B]

Thanks. Can you describe the hardware being used for such recordings and a few examples of such recordings? As far as I have read ADCs being used in audio do not convert analog signals directly to PCM 382/24 - the ADCs are delta sigma and do not have 24 bit resolution. But I have not followed the subject for the last few years.

I think I see what you are getting at...Almost all available DXD recordings are Merging Horus/Hapi interfaces, or DAD AX32/MTRX. They are delta sigma chips, AKM I believe. I don't personally think DS disqualifies a converter, even MSB's own ADC is DS. There are no R2R ADCs that go above 20 bit performance currently, and it is a hard stop where they can only make resisters up to 20 bit and add 4 bits of digital padding.

The dynamic range in the past was around 125db-ish for Merging cards, which in performance equivalence is 21 bit. The new cards are pretty close to 24 bit performance, at 136db. These cards do indeed create an actual 24 bit digital signal, but performance on the analog side is not quite there.

Again, I don't equate analog noise floor with digital bit depth.

 

[Carlos269]

HAgain, I don't equate analog noise floor with digital bit depth.

Jussi Laako, with his HQPLAYER, has demonstrated to me that you can hear deep into the noise floor when certain filters and modulators are used to extract and accentuate that inner detail and low level information.

 

[Ian B]

Jussi Laako, with his HQPLAYER, has demonstrated to me that you can hear deep into the noise floor when certain filters and modulators are used to extract and accentuate that inner detail and low level information.

I very much believe that.

 

[Rexp]

Eelco Grimm of Grimm Audio discussing why SACD and CD are flawed, among other things, starts at 9.15min:

 

[AMR / iFi audio]

The main issue with using DSD in the studio is the fact, that it is impossible to edit it. It needs to be converted, which kind off kills the appeal.
On the other hand, MoFi used Merging's ADKG8 converter cards in their mastering process, and everybody were happy with the effect...

 

[Carlos269]

The main issue with using DSD in the studio is the fact, that it is impossible to edit it. It needs to be converted, which kind off kills the appeal.
On the other hand, MoFi used Merging's ADKG8 converter cards in their mastering process, and everybody were happy with the effect...

This is not true.. Read posts #47 & 48 above.

 

[Carlos269]

This is not true.. Read posts #47 & 48 above.

The Genex DSD DAW was also DSD-wide for editing.

 

[Ian B]

This is not true.. Read posts #47 & 48 above.

There are definitely some who have, through repetition, created a widespread notion that DSD can't be edited, but the claim has always been dishonest. This is because of how they define what "editing" is. DSD definitely can be edited in the conventional sense, it can have volume changes, and even multiple channels can be mixed in Sonoma.

What certain DSD detractors have done is redefine "editing" into things like digital EQ, autotune, unlimited multichannel mixing, digital reverb, sampling etc. When they say "DSD can't be edited", they really mean that DSD isn't capable of advanced DSP and complex in-the-box digital production like is done with modern pop. Most us would not call that editing.

The criticism also implies that good recordings can't be produced outside of an ITB digital plugin environment. The reverse is often true: Most of the best recordings historically have little to zero digital processing (I'm excluding reverb etc). Pyramix and Sonoma (and the old Genex system) can be used exactly like a tape machine, but with more editing and track capability, and provide higher sound quality in an analog mix or mastering environment than is possible with PCM ITB projects. There is a lot of misinformation.

 

[AMR / iFi audio]

This is not true.. Read posts #47 & 48 above.

I stand corrected. Never heard about those systems before, I'll have to read more about them. Very interesting that they did it. So you can do cutting, mixing and volume control on DSD files. Is that all? Everything else is not possible without conversion, is it?

 

[Carlos269]

I stand corrected. Never heard about those systems before, I'll have to read more about them. Very interesting that they did it. So you can do cutting, mixing and volume control on DSD files. Is that all? Everything else is not possible without conversion, is it?

On my Sadie 5 DSD8 DAW, all crossfades, level controls, EQ’s, and dynamic processes are performed real time at DSD rate (2.8224 MHz) without conversion of the audio to PCM.