IPB

Welcome Guest ( Log In | Register )

4 Pages V   1 2 3 > »   
Reply to this topicStart new topic
32-bit capable DACs, Split from: "WASAPI plug-in version 3.0 beta" (94907)
SoNic67
post May 26 2012, 00:54
Post #1





Group: Members
Posts: 108
Joined: 3-February 11
Member No.: 87877



I don't know why people obsess about 32 bit "support" when their device manufacturer clearly states that that format is not supported. The DAC chips included on Xonar soundcards are regular 24 bit chips...
IMO, 32 bit is a worthless waste of space, all the '32 bit capable' DAC chips existent today have actual resolution less than 24 bit. Their catalog data is equal or even less than the top-of-the-line 24 bit DAC.
It's just shamless marketing and amazingly, enough people bite the bait.
The new beta plug-in (ver 2) works fine on E-MU 1820 w/ Win7 x64 and foobar ver 1.1.12 beta 6.

This post has been edited by SoNic67: May 26 2012, 01:04
Go to the top of the page
+Quote Post
Mr.Duck
post May 26 2012, 13:05
Post #2





Group: Members
Posts: 80
Joined: 26-March 09
Member No.: 68393



QUOTE (SoNic67 @ May 26 2012, 00:54) *
IMO, 32 bit is a worthless waste of space, all the '32 bit capable' DAC chips existent today have actual resolution less than 24 bit.

Twistedpear's Buffalo III has a 32bit DAC.
Go to the top of the page
+Quote Post
lvqcl
post May 26 2012, 13:24
Post #3





Group: Developer
Posts: 3362
Joined: 2-December 07
Member No.: 49183



QUOTE (Mr.Duck @ May 26 2012, 16:05) *
Twistedpear's Buffalo III has a 32bit DAC.

And...? As SoNic67 said, it has actual resolution less than 24 bit.
From leonvb-Buffalo_III_DAC_Integration_Guide_V1.2.5.pdf :
THD+N (with IVY III, mono mode): -120dB
(in mono mode "all 8 balanced DACs of the ES9018 are used for each output channel achieving the best possible dynamic range")
Go to the top of the page
+Quote Post
Mr.Duck
post May 26 2012, 13:51
Post #4





Group: Members
Posts: 80
Joined: 26-March 09
Member No.: 68393



Maybe someone wants 32bit output to their DAC. It's hardly just "shamless marketing" and a "worthless waste of space". Maybe I misunderstood what SoNic67's post was trying to convey.
Go to the top of the page
+Quote Post
phofman
post May 26 2012, 14:58
Post #5





Group: Members
Posts: 300
Joined: 14-February 12
Member No.: 97162



They are obsessed because they want to be obsessed. Obsession and proper understanding are often in the opposite corner.

32bit DACs make sense for designers since they do not have to care about bit decimation from 32 to 24 (i.e. most PCI sound interfaces support 32bit DMA samples only, yet they have to output 24bits on their I2S lines to codecs.
Go to the top of the page
+Quote Post
SoNic67
post May 26 2012, 19:23
Post #6





Group: Members
Posts: 108
Joined: 3-February 11
Member No.: 87877



QUOTE (phofman @ May 26 2012, 09:58) *
32bit DACs make sense for designers since they do not have to care about bit decimation from 32 to 24 (i.e. most PCI sound interfaces support 32bit DMA samples only, yet they have to output 24bits on their I2S lines to codecs.

Padding zeroes is the default DMA mechanism. Why store those zeroes on HDD? You don't have to worry about 32 bit decimation - unless you are a recording studio with 32 bit ADC. Let me know what mixing console has that ADC's...
QUOTE (Mr.Duck @ May 26 2012, 08:51) *
Maybe someone wants 32bit output to their DAC. It's hardly just "shamless marketing" and a "worthless waste of space". Maybe I misunderstood what SoNic67's post was trying to convey.

Let me try it one more time smile.gif
For real audio resolution, the number to look for is the THD+N. That includes the noise and distortions on output (both are not part of original music). Most of the top DAC's are in the -105...-110dB range here. Some manufacturers use % to hide it, for example a THD+N of 0.0003% means -110dB.
The best performing 32 bit DAC on market is ESS Sabre 9012/9018. Listed by manufacturer with a THD+N of -120dB.

Now... a 22 bit audio signal represents a range of 132dB. Or in (%) will be 0.000024%. If your DAC doesn't have at least those numbers for THD+N, then it cannot reproduce the 22 bit correctly. Even the above Sabre32 doesn't "touch" those 22 bit...
Everything more than that is just noise and distortion added to the musical signal and sold as "32 bit magik". Wasted storage space and bandwidth.
Most of the PC soundcards don't even rise to 18 bit level of true analog quality.
24 bit was adopted because is a round number of 8 bit packets, not because it adds something to the final quality above 22 bit mark...

This post has been edited by SoNic67: May 26 2012, 19:34
Go to the top of the page
+Quote Post
Jackal29a
post May 26 2012, 19:31
Post #7





Group: Members
Posts: 36
Joined: 28-May 11
Member No.: 91053



I'm quite surprised by some people's reactions, it has been stated here that both ASIO and WASAPI provide no advantage whatsoever over DS therefore being as pointless as 32bit output so, why not ditch these plugins altogether? the same could possibly said about FLAC, APE or any other lossless codec that provides no audible advantage over well encoded 192Kbps, and so on and so forth.

I've never, not once, claimed 32bit sounded better, had any other advantage or that it was accepted by any other PCM179x DAC - other that the PCM1795 and, as Musiland discovered as an undocumented capability, the PCM1798. In fact I did write that I didn't give a bl**dy rat's a*se about it. I was interested in it because other player I mentioned can do it thus it can indeed be done. I just wondered why Foobar couldn't. That same player can also send WASAPI @ 88.2 or 176.4 to the Xonar whereas Fooobar (and most others for that matter) cannot reporting "not supported", just in case someone want to split this thread and create a new "88.2 and 176.4KHz capable DACs" thread, I AM NOT saying or implying in any way there is any advantage in playing such material or that it sounds any better. OK?


Go to the top of the page
+Quote Post
SoNic67
post May 26 2012, 19:36
Post #8





Group: Members
Posts: 108
Joined: 3-February 11
Member No.: 87877



Foobar in my opinion does the right thing telling you that that format is not supported. The Musiland driver/software lies and serves you a 24 bit claiming that is 32 bit. PCM1798 is a 24 bit DAC per manufacturer datasheet.

This post has been edited by SoNic67: May 26 2012, 19:38
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 19:48
Post #9





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (SoNic67 @ May 26 2012, 14:36) *
Foobar in my opinion does the right thing telling you that that format is not supported.


That has nothing to do with the hardware. Its just dependent on the driver you're using. My 16 bit onboard will happily accept 32 bit input from foobar. You're probably using some weird driver for ASIO or whatever that doesn't support 32 bit.

QUOTE (Mr.Duck @ May 26 2012, 08:51) *
Maybe someone wants 32bit output to their DAC.


Then they should use AC97 onboard sound and foobar2000. Works great.
Go to the top of the page
+Quote Post
SoNic67
post May 26 2012, 19:55
Post #10





Group: Members
Posts: 108
Joined: 3-February 11
Member No.: 87877



What is really representing the 32 bit support implemented in those WASAPI components?
My soundcard E-MU 1820m seems to "work" with WASAPI 32 bit selected (like with 24 bit). But I know that the DAC inside is a Cirrus CS4398, 24 bit one. Creative doesn't advertise 32 bit capability in their Win7 drivers.
So... I am confused. Where is this "32 bit" coming from?
I know that DirectSound will accept any bitrate/bitdepth and convert those on the fly (badly) to match the capabilities reported by the sound card driver. Is this similar?

This post has been edited by SoNic67: May 26 2012, 19:57
Go to the top of the page
+Quote Post
SoNic67
post May 26 2012, 20:02
Post #11





Group: Members
Posts: 108
Joined: 3-February 11
Member No.: 87877



I said that the driver is the one that "lies"... Probably uses DS to change the bitrate/bitdepth to match the real capabilities? In this case using WASAPI with those drivers would be useless...
Go to the top of the page
+Quote Post
IgorC
post May 26 2012, 20:03
Post #12





Group: Members
Posts: 1556
Joined: 3-January 05
From: ARG/RUS
Member No.: 18803



QUOTE (SoNic67 @ May 26 2012, 15:23) *
For real audio resolution, the number to look for is the THD+N.

Can You defend this statement with some additional information?

Then why include Dynamic Range into specification? Just go for THD+N, right?

This post has been edited by IgorC: May 26 2012, 20:11
Go to the top of the page
+Quote Post
Jackal29a
post May 26 2012, 20:34
Post #13





Group: Members
Posts: 36
Joined: 28-May 11
Member No.: 91053



The Musiland driver doesn't lie, the USB receiver IC accepts that bit depth just fine and then truncates it to 24bit which is what is sent to the DAC. In the 03US series the signal is not truncated because contrary to what specs say the PCM1798 does accept 32bit though, obviously, its real performance is roughly 20bit. The PCM1795 is listed at 3.30USD while the 1798 is a 2.95 part, it makes sense for TI not to admit they are that similar.
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 20:48
Post #14





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (SoNic67 @ May 26 2012, 15:02) *
I said that the driver is the one that "lies"... Probably uses DS to change the bitrate/bitdepth to match the real capabilities? In this case using WASAPI with those drivers would be useless...


My point is that foobar is not doing anything special. You're just using a driver that doesn't support 32 bit, so if you try to use 32 bit, it doesn't work.
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 20:55
Post #15





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (IgorC @ May 26 2012, 15:03) *
QUOTE (SoNic67 @ May 26 2012, 15:23) *
For real audio resolution, the number to look for is the THD+N.

Can You defend this statement with some additional information?

Then why include Dynamic Range into specification? Just go for THD+N, right?


THD is used because in the old days it was easier to compute then dynamic range. But now that we have computers, in some sense its unnecessary, since its usually dynamic range you actually want. However, THD does have the advantage that its somewhat standardized in meaning, so you at least have a good idea whats actually being measured. Dynamic range less so, since different people pick different ways to measure it, and often the one that makes them sound the best. THD+N at 1khz for instance is harder to fudge.
Go to the top of the page
+Quote Post
Mr.Duck
post May 26 2012, 21:06
Post #16





Group: Members
Posts: 80
Joined: 26-March 09
Member No.: 68393



QUOTE (SoNic67 @ May 26 2012, 19:23) *
For real audio resolution, the number to look for is the THD+N.

THD+N includes noise. There is only so far you can improve this number for practical reasons such as thermal noise stopping it going any better. That's not the same thing as dynamic range which is a different spec.

Besides, specs aren't everything. Different DACs might measure the almost the same but that doesn't mean they would sound almost the same.
Go to the top of the page
+Quote Post
IgorC
post May 26 2012, 21:52
Post #17





Group: Members
Posts: 1556
Joined: 3-January 05
From: ARG/RUS
Member No.: 18803



QUOTE (saratoga @ May 26 2012, 16:55) *
THD is used because in the old days it was easier to compute then dynamic range. But now that we have computers, in some sense its unnecessary, since its usually dynamic range you actually want. However, THD does have the advantage that its somewhat standardized in meaning, so you at least have a good idea whats actually being measured. Dynamic range less so, since different people pick different ways to measure it, and often the one that makes them sound the best. THD+N at 1khz for instance is harder to fudge.


Thank You.


Then it makes me think that THD+N better than -95 ...-100 dB has little sense.

Untill the moment best headphones's THD I known it's HD800's one. It's <0.02% (-74 dB). Electrostatic phones don't count as they require a special dedicated type of amplification.
If soundcard has THD+N -20 dB below of HD800's (-74 dB), let's say -94 dB then final THD of the soundcard + headphones will be (-94 dB) + (-74dB) = -73.96 dB. Further improvement of soundcard's THD+N is pretty pointless.

This post has been edited by IgorC: May 26 2012, 22:00
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 21:54
Post #18





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (Mr.Duck @ May 26 2012, 16:06) *
QUOTE (SoNic67 @ May 26 2012, 19:23) *
For real audio resolution, the number to look for is the THD+N.

THD+N includes noise. There is only so far you can improve this number for practical reasons such as thermal noise stopping it going any better. That's not the same thing as dynamic range which is a different spec.


Generally speaking, you can usually calculate dynamic range THD with reasonable accuracy, so they're not entirely different.

QUOTE (Mr.Duck @ May 26 2012, 16:06) *
Besides, specs aren't everything.


No, but measurements are.

QUOTE (Mr.Duck @ May 26 2012, 16:06) *
Different DACs might measure the almost the same but that doesn't mean they would sound almost the same.


Unless you've screwed up somehow, it does mean so actually. If you want to talk about audibility, pretty much anything with a flat frequency response and > 70-80dB will sound the same in any real world test. Of course, you have to measure properly, which means with the actual headphones hooked up and at the level you're planning to listen to.

Specs better then that are mostly about bragging rights and about headroom if you eventually want to use the output to drive a more difficult pair of headphones.
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 21:58
Post #19





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (IgorC @ May 26 2012, 16:52) *
Untill the moment best headphones's THD I known it's HD800's one. It's <0.02% (-74 dB). Elestrostatic phones don't count as they require a special dedicated type of amplification.
If soundcard has THD+N -20 dB below of HD800's (-74 dB), let's say -94 dB then final THD of the soundcard + headphones will be (-94 dB) + (-74dB) = -73.96 dB. Futher improvement of soundcard's THD+N is pretty pointless.


Yes, in that case it is indeed pointless as you've calculated. However, keep in mind that while a big pair of headphones like the HD800s may be hard to drive all that loud, they don't take all that much current. If you swapped them out for a pair of very low impedance balanced armature IEMs, you might find that your THD increases a thousand fold or more. So in principle you may still want better equipment, depending on what you listened to.
Go to the top of the page
+Quote Post
naturfreak
post May 26 2012, 22:01
Post #20





Group: Members
Posts: 176
Joined: 16-October 03
Member No.: 9338



As far as I know there is a upper physical limit of the achivable Signal-to-noise-ratio in the domain of analog signals.
According to J.B. Johnson this limit is about 131 dB for a bandwith of 20 kHz.
(Johnson–Nyquist noise)
So in theory, 22 bits of sample depth should be sufficient. There is no need for 32 bit DACs, 24 bit DACs are good enough in any case.

Furthermore there are no headphones or speakers that can reproduce more than about 100 dB of dynamic – at least no affordable that I know - without noticeable distortions.

This post has been edited by naturfreak: May 26 2012, 22:11
Go to the top of the page
+Quote Post
IgorC
post May 26 2012, 22:12
Post #21





Group: Members
Posts: 1556
Joined: 3-January 05
From: ARG/RUS
Member No.: 18803



QUOTE (naturfreak @ May 26 2012, 18:01) *
According to J.B. Johnson this limit is about 131 dB for a bandwith of 20 kHz.

Those are dBm. -131dBm is -161dB

This post has been edited by IgorC: May 26 2012, 22:13
Go to the top of the page
+Quote Post
Mr.Duck
post May 26 2012, 22:12
Post #22





Group: Members
Posts: 80
Joined: 26-March 09
Member No.: 68393



QUOTE (saratoga @ May 26 2012, 21:54) *
No, but measurements are.

I mean it's performance is measured to find it's specs (performance specifications).


QUOTE (naturfreak @ May 26 2012, 22:01) *
So in theory, 22 bits of sample depth should be sufficient. There is no need for 32 bit DACs, 24 bit DACs are good enough in any case.

In theory... but I am not convinced. So there is a noise floor limiting measured performance... how about we go the other way and have a DAC outputting ~20V RMS instead of the usual level of around 1-2V RMS. Wouldn't that help achieve better results?
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 22:13
Post #23





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (naturfreak @ May 26 2012, 17:01) *
As far as I know there is a upper physical limit of the achivable Signal-to-noise-ratio in the domain of analog signals.
According to J.B. Johnson this limit is about 131 dB for a bandwith of 20 kHz.


Assuming you're refering to the noise power table on that wikipage, keep in mind that is in units of dBm, that is power relative to 1 milliwatt. So you are limited to an SNR of 131dB for a 1 mW signal power, but at 1 watt would be limited to 161dB.

That said, you are right that thermal effects become extremely problematic as one gets much above 20 effective bits. And simply ramping up the power introduces its own problems (such as thermal heating of components) that in turn tend to reduce rather then improve SNR. In practice, measuring 24 effective bits at room temperature seems to be extraordinarily difficult even for scientific equipment.
Go to the top of the page
+Quote Post
naturfreak
post May 26 2012, 22:26
Post #24





Group: Members
Posts: 176
Joined: 16-October 03
Member No.: 9338



It ist even worse in the case microphones are involved, because the output signal of a average microphone without amplifier is only around -40 dBm, but the noise level is at around -130 dBm. Therefore 90 dB S/N is the best you can get in this case.
Amplifers produce additional noise. You simply can't lower the level of noise by using amplifiers.
Go to the top of the page
+Quote Post
saratoga
post May 26 2012, 22:26
Post #25





Group: Members
Posts: 4922
Joined: 2-September 02
Member No.: 3264



QUOTE (Mr.Duck @ May 26 2012, 17:12) *
how about we go the other way and have a DAC outputting ~20V RMS instead of the usual level of around 1-2V RMS. Wouldn't that help achieve better results?


In practice, probably not. Most of the best devices seem to operate around a few volts. Even those A/Ds that measure larger voltages tend to use a preamp stage to throw away extra voltage. All that extra voltage introduces problems of its own, including the need to use much larger resistor values (which are of course much more noisy) to keep self heating down to a reasonable level. Additionally, high voltage semiconductor logic has its own problems.
Go to the top of the page
+Quote Post

4 Pages V   1 2 3 > » 
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 29th August 2014 - 16:06