Need a GOOD resampling program

[Rainervs]

Our church has been recording music at 96/24, and it sounds very good. We plan on distributing it on DVD at 96/24. But we also need to produce CDs at (ugh) 44.1/16.

All of the resampling algorithms and programs I have tried so far add noticeable (and objectionable) artifacts to the sound ... our music director described it as a "high frequency sizzle". It's least obvious on highly tonal sounds (a solo instrument), and worst on massed choral singing. I'd call it a lack of coherence -- a loss of "palpable presence" -- a bit reminiscent of stylus mistracking on an LP.

The best-sounding resampler I've found so far is Resample 1.1 by SoundsLogical -- polyphase filtering with choices of dither. The worst-sounding one is the "high quality" resampler built into Cakewalk Sonar 3.1 -- sinc method.

Any suggestions?
Thanks,
Rainer

[dwk123]

I haven't tried it for downsampling, but from a mathematical/theoretical perspective I beilve that ssrc available from shibatch.sourceforge.net is pretty close to state-of-the-art. It is a frequency-domain approach and so only certain ratios are supported, but 44.1/96 is certainly possible.

Free and easy to try, so you can't go wrong.

[Rainervs]

Thank you!

I found SSRC with no trouble, and have tried it on two of my most difficult files. It's better than everything else I've tried so far!

Of course, it's not quite "perfect", so I'm still interested in other suggestions (even those costing money). But I'll start using SSRC, and it will improve my CDs. It's also fast -- about 6X real time speed. (Resample was 0.8X).

Thank you!

Rainer

[Gordon McGregor]

The perfect choral singing means you need to minimize intermodulation distortions in your downsampling process. One of the good ways - to use a perfect soundcard as Lynx L22, for example, for such purpose, it has very good IMD measurements and will distort your signal less that any other soundcard. You may try different dither types, they are implemented in this soundcard as well. It should be good with SSRC and I believe that you will be satisfied finally with the result.

[Rainervs]

I don't think the problem lies in my sound cards. I hear the same clouding/sharpness on my M-Audio card and my Sony ES CD player when working from the 44/16 version; this distortion is almost totally absent with the 96/24 original through the very same M-Audio card.

True, it gets (much) worse when played on a crummy CD player or a bad sound card. But if the 44/16 version shows problems that the 96/24 version does not, on the very same hardware, it certainly seems like the porblem lies in the resampling -- or in the inherent limitations of 44/16.

The sharpness introduced by ssrc was not obvious when I sampled the original live performance audio at 44/24 instead of 96/24 -- so that sort of rules out the sampling rate. There were other shortcomings with 44/24 sampling (mostly loss of "palbable presence").

This work was done with M-Audio Audiphile 2496 and with M-Audio Delta 1010-LT sound cards.

Rainer

[Gordon McGregor]

Originally posted by Rainervs
I don't think the problem lies in my sound cards. I hear the same clouding/sharpness on my M-Audio card and my Sony ES CD player when working from the 44/16 version; this distortion is almost totally absent with the 96/24 original through the very same M-Audio card.

The problem is not in your sound card, it is in downsampling itself. It is very duifficult to perform it flawlessly. Re-sampling means using of DSP and it's algorithms, and here the card's performance plays very serious role ...

The sharpness introduced by ssrc was not obvious when I sampled the original live performance audio at 44/24 instead of 96/24 -- so that sort of rules out the sampling rate. There were other shortcomings with 44/24 sampling (mostly loss of "palbable presence").

Correct, you got the distortions at the stage of downsampling and then at the stage of downconversion.

This work was done with M-Audio Audiphile 2496 and with M-Audio Delta 1010-LT sound cards.
Rainer

Rainer, Envy 24 DSP chipset never produced the "correct" sound, at least at the level you require.
http://www.io.com/~kazushi/audiocard/audiophile/

[BrianL]

Speaking of intermodulation in choral music, read Dave Griesinger's
paper on acoustic intermod created by such choirs.

But, yes, a capella choral music, especially in a reverberant acoustic
is very revealing of processing. I know it most readily shows
up the artifacts in compression like MP3, so I'm not surprised
that you're hearing problems from downsampling.

[Frazzled]

I use Audioactive Production Studio, it comes with the Fruanhofer-Gesellschaft Codec and is very good at resampling.

[Rainervs]

Originally posted by Frazzled
I use Audioactive Production Studio, it comes with the Fruanhofer-Gesellschaft Codec and is very good at resampling.

A quick Google search suggests that the Fraunhofer-Gesellschaft Codec, and the AudioActive Proiduction Studio, are for creating MP3 files. I have almost no interest in MP3. I'm just looking for a way to convert a PCM wave file at 96/24 to a PCM wave file at 44.1/16 and 48/16. Adding the compression problems of MP3 can't possibly help. Any other suggestions?

Thanks,
Rainer

[Rainervs]

Originally posted by BrianL
Speaking of intermodulation in choral music, read Dave Griesinger's
paper on acoustic intermod created by such choirs.

Thanks for the suggestion. I found his home page, and an incredible bibliography. But I can't recognize the paper you're referring to. And Google can't find anything on his site using the word "choral". Can you give me a more specific reference, or just the correct title?

Thanks,
Rainer