INTERACT FORUM
More => Old Versions => Media Center 11 (Development Ended) => Topic started by: DocLotus on March 18, 2003, 12:23:02 pm
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,Hi gang;
I'm back on the great ASIO race (or is it just a game after all?).
Ran into something really weird. CD players operate at 44,100 Hz, the CD is cut at 44,100 Hz, and MJ should be set up for 44,100 Hz (for most normal playback of ripped CD's).
So I'm asking why does ASIO have to be set up for 48,000 Hz?
There's a story here... read on.
I loaded the kX Project drivers to get ASIO on my Creative Audigy soundcard. After much screwing around I finally got ASIO working... sort of. Had much clicking & popping with the 3528 drivers. Had better luck with the latest 3530 version. Also more things worked with the 3530.
However, some people have said they heard an immediate improvement in the sound with ASIO. I did hear a difference but not any apparent improvement... in fact I think it was a little worse if anything.
The last couple of days I have been playing a lot of piano music (jazz & new age) & noticed a pronounced sharp, tinny, unnatural sound to all the piano music especially the sharp hi-frequency attacks. This was not apparent with almost all other music that I heard although I did hear a difference..
This was driving me nuts as my new Logitech Z-680 speakers are a real jewel of a sound producer & it sounded just like a ripped speaker cone... all rattlely & irritating.
So the hunt was on for the cause.
* Replaced the Coaxial digital input from the speakers with a three wire analog input... no improvement!
* Un-installed the kX Project drivers & re-installed the Audigy software... no improvement.
* In MC changed the playback from ASIO back to Direct sound... no improvement.
* In DSP Studio changed the 5.1 Channels back to source input... no improvement.
Was about to pull my remaining hair out by the roots when I noticed the DSP Sampling Rate setting of 48,000 Hz. Changed it back to 44,000 Hz & all was well again in music land... finally!
Seems like the sharp attack of piano music really drives a system to its musical limits.
So, now I ask again... why 48,000 Hz with ASIO? It was the problem on my system all along.
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On AC97 ("consumer grade") soundcards, pretty much anything is resampled to 48KHz before being output (via the analog or digital outs.). I wrote "pretty much anything", because some sound cards such as the Audigy2 can go around this limitation for DVD-audio, for instance.
Professional cards (such as the M-audio or RME products) do not have this limitation, and can output a digital signal at 44.2, 48, 88.4kHz, etc. I understand that this violates the AC97 specs, but it also means potential bit perfect output for CDs.
A side benefit of the ASIO drivers (the initial reason for this standard was low latency in recordings), is that they bypass the WDM k-mixer, a piece of software that M$oft developed and which has a bug which distorts the digital signal. Using ASIO removes one cause for distortion (until MS fixes the bug), so the output should sound a little bit better. Resampling CDs is another source of distortion...
Hope this all makes some sense
Eiffel
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Looks like there's a bug in our resampling. It'll be fixed in a build or two.
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KX audio driver is stick with 48,000, take a look @ the Kx project forum
http://www.driverheaven.net/forumdisplay.php?s=&forumid=67