I'd go along with JohnV on this one, since I've had problems with samples sounding better lowpassed. As for the frequency, I used the PCABX Training Room to test my limits, and I'd say either the 15 or the 18 kHz, as those are the ones where I actually had to focus.
Should I include Atrac3 (used on Sony MiniDiscs and Real Audio at mid-high bitrates) in this test? Is there anyone out there interested in this format? (besides Den )
If you use the Sony software, there is no export as wav option.
Sounds like a job for TotalRecorder. It's a pain in the ass, but it can be done.
In my opinion, ATRAC3 is interesting to include in this test for one reason only : Minidiscs performance. If the codec doesn't match with MD device, it's useless. In other words : sonicstage (+ Total Recorder) or nothing.
When you'll be trying WMA9, be sure to test both Std and Pro. The latter one is very well able to compress 44khz stereo at 128kbit, and it seems to sound better. It's also a PC playable format, neglecting it would be disappointing.
Personally I'd be ready to drop MusePack from this low bitrate test. Imo MPC lowbitrate has no practical meaning to most people or even to MusePack users outside "nice to know"-factor. I don't believe many people will be using MusePack at this low bitrate even if it does well in the test.
About the samples: Guruboolez raised a question that there is no real classical sample (both classical samples in the 64kbps test were replaced with problem cases). So, do people agree with exchanging, say, LifeShatters (that is a bit redundant, stylewise, to BlackWater and Thear1) with Bachpsichord? Or people have another suggestion about a sample to be replaced?