W A R N I N G !

W A R N I N G !

This page is full of non-facts and bullsh!t, (just like the internet and especially forums and other blogs), please do not believe entirely without exercising your intellect. Any resemblance to real things in reality is purely coincidental. You are free to interpret/misinterpret the content however you like, most likely for entertainment, but in no case is the text written on this blog the absolute truth. The blog owner and Blogger are not responsible for any misunderstanding of ASCII characters as facts. *cough* As I was saying, you are free to interpret however you like. *cough*

Saturday, May 29, 2010

Testing your sound card for bit-perfect output - the DTS test - computer version

For people who don't have an AVR/DTS decoder

1) Download a DTS file from above
2) Rename it to .wav, when played you will hear white noise
3) Get Cool Edit (Audacity will not work)
4) Connect SPDIF-out to SPDIF-in of your card (of choice, can be same card, can be different)
Set-up for recording through SPDIF
5) Configure the source soundcard's output - SPDIF sampling rate same as source file, master and/or wave volume max, no effects/filters
6) Play through player of your choice - DS, KS, ASIO, anything
Press play before recording
7) Click the red button to start recording - select the same sampling rate as your source file/card, for resolution if the source is 16-bit select 16-bit, if 24-bit select 32-bit (float) - not verified
8) If done correctly you should see a square wave of -12dB, which is white noise when played back
9) Save as Windows PCM (*.wav) file
10) Rename to .dts
11) Play with your player, if music comes out, DTS test pass

Note - My method is quite different from what most others had said on the internet, particularly the part requiring BeSplit. What's different about my method is that mine works for me and that doesn't, and as can be seen from the replies that also doesn't work for many others asking how to do the same thing.
I will not say that method doesn't work, but if you find that it doesn't work for you, try alternatives.

Results - 44.1kHz/16-bit Stereo source file

Note - the "Xonar D2" (in inverted commas) is actually a HT Omega Claro running on Xonar D2 drivers. It was like this before the test and I did not bother changing it back because the drivers are largely the same, I would not expect any difference between different versions of the driver
C-Media Oxygen ASIO is the ASIO driver for CMI8788-based cards

Player used: foobar2000 unless otherwise stated

Prodigy 7.1 HiFi comes with a flexible clock system that supports [b]auto-detection and changing of sampling rate[/b] or can be locked to a manually chosen frequency, in which case resampling takes place if needed, or it can derive its clock from incoming SPDIF signal.

Prodigy (auto sampling rate unless specified)

Prodigy KS - ok
Prodigy ASIO - ok
Prodigy DS - ok
Prodigy QVE - waveform reduced in amplitude, file not recognized

Prodigy KS (reduced volume in foobar) - file not recognized
Prodigy KS (volume reduced midway) - file stops midway
Prodigy KS (locked frequency =/= 44.1kHz) - foobar returns error
Prodigy ASIO (locked frequency =/= 44.1kHz) - frequency force changed in control panel, foobar proceeds as normal - ok
Prodigy DS (locked frequency =/= 44.1kHz) - frequency remains locked, foobar proceeds as normal, Windows resamples sound, file not recognized
Prodigy QVE (locked frequency =/= 44.1kHz) - frequency forced changed in control panel, foobar proceeds as normal, waveform reduced in amplitude, file not recognized

"Xonar D2"

"Xonar D2" KS 44.1kHz - ok
C-Media Oxygen ASIO 44.1kHz - ok
"Xonar D2" DS 44.1kHz - ok
"Xonar D2" DS 44.1kHz (reduced volume in Windows) - file not recognized
"Xonar D2" Windows Media Player 44.1kHz - ok

Two numbers show combination of source card's output sampling rate and sampling rate selected in Cool Edit

"Xonar D2" KS 48-44 - waveform does not look like DTS
"Xonar D2" KS 48-48 - waveform does not look like DTS
"Xonar D2" KS 44-48 - waveform looks like DTS, file not recognized

Realtek ALC888S

ALC888S Windows Media Player 44.1kHz - ok

Also to be noted: When using Prodigy's internal M-Clock to record others, pops/noise occur at regular intervals. Hows that for the supporters of synchronous reclocking?

Important things to note

- possible to pass DTS test using DS and WMP if all volumes are set to max
- card only passes test if the SPDIF output sampling rate is set to the same as whatever the player is sending it through DS/KS/ASIO - take note if you're not using a card with automatic sampling-rate changing
- Realtek (non-AC'97 version) is capable of passing DTS test

Possible follow-ups

- test with 48kHz and >48kHz source files

And while I'm at it, here's a screenshot of a 192kHz file recorded through TOSLINK for those who still believe it cannot be done

Whether the equipment can do 192/24 or above is up to the parts used. The Prodigy 7.1 HiFi sends and receives 96kHz max, but the Omega Claro and Realtek can do 192.

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