[dhwilkin]

For anybody interested, Creative has officially announced its upcoming Audigy processor. The press release is here. I believe cmoy has also posted a brief notice about this on Headwize.

 

[lini]

dhwilkin: Yup - I wrote a news for our site, too. Nevetheless I was quite disappointed, because Creative's info neither covers DACs nor resampling, yet.

Greetings from Munich!

Manfred / lini

 

[dvsone]

Here is some info on the DAC:

Sound Blaster Audigy delivers stunning audio clarity in multi-channel through 24-bit/96kHz digital-to-analog converters (DACs), producing an outstanding 100dB signal-to-noise ratio (SNR). This dramatic increase in audio quality is attributed to the Audigy's high definition components.

 

[Odeen]

EVERY DirectX-compatible soundcard must resample digital input internally to 48khz.

Otherwise it won't conform to the mixing specs specified by Microsoft, and it won't be a DirectX-compatible card... But why not add some sort of a de-interpolation mechanism to the DAC that can do specific 48,000 to 44,100 hz de-interpolation and get back the original signal?

I figure, you don't LOSE any samples, you just add one every 11 samples or so - so why not take out that exact one every 11 samples, using the reverse of the algorithm you use to interpolate?

 

[Redwoood]

I don't think upsampling works like that - adding one every 11 samples.
If it did, it would be like playing the first 11 at a higher speed (pitch!) and then the 12th - changes the sound totally.

Bye

Redwoood

 

[Odeen]

I always thought that the pitch (and the rest of the aspects of the sound) was controlled by the contents of the 16-bit word, and sampling rate was merely how often the words were reproduced or captured..

So, if you play back at a higher sample rate, each 16-bit "sound" would be heard not for 1/44100th of a second, but for 1/48000th of a second...

 

[DanG]

You can't really hear each sample, because it's really just an amplitude or instantaneous pressure. But it is true that increasing the sampling rate will not necessarily affect pitch -- unless, of course, you use the exact same samples and just push them closer together! I'm not sure, but my guess would be that the whole signal has to be represented again with totally different samples so that you have 48,000 samples per second which together make approximately the same sound that the 44,100 samples-per-second signal made. So it's not just adding an extra sample, it's totally re-inventing the signal. Which is why such an apparently small change in sampling rate can so adversely affect the sound.

 

[Redwoood]

That's exactly what I was thinking Dan.

If you play the old 11 samples at a higher speed, you alter the pitch.

To do it properly you would have to interpolate the signal through the 11 original points. Then decrease the intervall size to 11/12 and 'sample' this interpolated signal at the new 12 points.
(which would be interpolated again during playback...)

I don't remember much of what we did in my numerical math class about this (it's ben quite a while), but there might be interpolation techniques that let you recover the original 11 points (though maybe not exactly) but either they aren't used because they produce bad sounding signals or they are used but are not good enough.



Bye

Redwoood

 

[chych]

I can confirm about the pitch change as I can practically do this from my sound card to DAC... resampling from 44khz to 48khz increases the pitch, it seems like the tempo is increased as well (though I don't think it has been). It sounds pretty funny though on some songs, heh...

 

[OneMalt]

The really bad news is that Creative has added hardware level SCMS checking...that sucks!

 

[Brian]

Here's some more info on the new card.

Apparently, you can finally choose the SPDIF out sampling rate. Now you can set it at 44.1, 48, or 96 i think, instead of having it be locked at 48.

Also all the jacks are now gold plated again, instead of those silly colored plastic ones on previous models to comply with the PC99 regulations.

All the drivers have been vastly improved and the card supports Dolby DTS passthrough and DTS Audio CDs, even in Win2000 now.

The new card does sound noticeably better than any other SoundBlaster in existance. Couple that with a remote for lazy people like myself who like to watch DVDs with one or use it in Winamp or any software CD player, and it's really not that bad of a card.

ASIO support is welcomed too, apparetnly the latency is about 2ms in most applications.

Now I'm not saying that it can touch a RME card or anything, but for a multipurpose card that supports ASIO, all the 3d games, DTS, and has a remote and lots of free (albeit sort of crappy) software, its a decent buy. Just run your CDROMs spdif to the card, set the output to 44.1, and combine it with a decent outboard DAC and you've got pretty damn good sound coming out of your PC.

 

[Cousin Eddie]

Brian,

Where are you getting your information? From what I understand by reading the response from Creative tech support on Creative's Audigy newsgroup, the card still samples everything internally to 48.

So you've heard the card? Are you using it with your computer? If you can find out if it really does allow choice of sampling rate, I'm sure a lot of us would appreciate it. The sampling rate issue is the Achilles heal of Sound Blaster's cards because generally all cards in that price range produce digital output with low jitter.

 

[Brian]

Sorry, maybe I should have worded that a bit differently. Yes, the Audigy works internally at 48Khz which is kind of frustrating, I just meant that you can configure it to output a 44.1 stream from the S/PDIF port, whereas with earlier generations of the Live card, the output was a 48Khz stream.

Also worth noting is that all of the resampling algorithms are supposedly much improved, which should translate to better quality when listening to CDs and whatnot.

I'm getting this information from both
http://www.3dsoundsurge.com
and
http://www.3dhardware.net

I also meant that the card sounds much better than any other Creative ones in terms of features/technology. Havent heard it for myself in action just yet. Damn, I sure know how to word things so that they can be easily misinterpreted. Sorry to cause any confusion. Now if only RME would make a card with a remote and support for games...

 

[ppl]

Wanted to bring this topic up again

 

[Audio-Me]

You guys do know that Creative Labs is pure crap for sound right? I hope none of you who are interested in this Audigy thing are audiophiles. Visit here for some enlightenment.