I know there a numerous "scientific" ways I can determine this on my own, but I'm feeling tad lazy today, so I'll just ask you guys instead.

I recently converted all my ape files to lossless WMA format. (Before I took the plunge, I did verify that going from ape to wma then back to ape lost no bits, i.e., the transcoded ape was identical to the original ape, so I am not too worried if I have to go back.)

Anyway, I have read that MS adds gain to their lossy WMA encodings, so maybe this is just a psychoacoustic thing, but now, when playing all my standard playlists, there seems to be a signficant increase in bass (lower frequencies) in most of the songs. I have Klipsch's Promedia 5.1 speakers, so this is quite noticeable. And no, the overall volume seems the same, only the lower frequencies are a lot more pronouced, some to the point of distortion.

Does Microsoft apply a DSP filter to my music without asking my permission?

And please, no Microsoft flames. I just want to know if this is my imagination or if someone actually knows for a fact that MS's lossless encoder reshapes the signal.

Thanks!

Omni

How do you play your wma files ? If you use WMP9, it could be the case that the player itself adds some sort of "bass enhancement" to the signal.

AFAIK, equalizing and saving a sound file will (just like normalizing does) alter the file in a non-correctable way, there will be rounding errors on single samples and changes in signal phase so this should not be lossless encoding anymore ... just because the original soundfile cannot be reconstructed IMO.

For me, the only possible way to explain that behaviour is that the playback software itself adds some bass (in that case). Maybe you should do some blind testing with wma9 lossless and ape ...

Oh, it varies. Mainly in Media Center 9, but also in MS Media Player.



That's a great point.



Actually, after I posted this last night, I did just that. You have to remember that this is sort of hard to do since ape-->wave and wma-->wave produce identical wave files. In other words, I could not truly ABX it; I could only repetitiously listen to each one.

The WMA file was definitely "bassier", but I only tried it with two songs. And I want to stress again that I didn't truly ABX it, so I wouldn't argue the point if some told me I was imagining things.

Omni

Are you trying to find out if the PLAYBACK of lossless wma's is modified, or the DECODING? It's out of quesiton that two identical files sound/work/look/act/whatever-you-want-to-put-here the same way.

To do so, you should maybe use TotalRecorder or something like that, which captures the audio that is sent to the soundcard, and try to abx with *that* wave file. Still, I would believe that it is the player, rather than the codec, the one that's doing something there.

I would bet my money on playback alterations ... maybe you should use winamp or db poweramp for playback just to be sure ...

Okay, this is just an update to conclude this thread (for when it gets listed in future forum searches).

I had the amazing simple idea (which is probably why I overlooked it B)) to psuedo-ABX the encoded files to the original CD. After dozens and dozens of "tests," if you can call them that, I have concluded that problem must be in my hardware drivers. I haven't figured out what changed, but I know with 100% certainty that something did change (coincidentally) around the time I converted all my files.

I tested with Media Center 9 (J.River) and Media Player 9 (Microsoft); and in MC9, I varied the output between wave out, DirectX, and ASIO. No matter what I use, everything is just too "bassy." (Rhetorical Question: Is it possible that my subwoofer is blown?)

Anyway, thanks for all your responses!

Omni

Sorry if you have already done this, but have you tried converting the wma9 file back to ape, and then comparing the new and the old ape files?

Yeah, as I stated in my original post, I did exactly that first to make sure I could go back if I so desired. (Sorry, I just don't trust Microsoft.) Based on this, my theory was that the WMA playback engine was somehow filtering the data stream applying some sort of DSP effects to it. This does not seem to be the case, though, as I describe in my previous post.

Omni

So Omni, were you ever able to figure out what was causing the "bassiness"? I am going to take the plunge and convert 500+ CDs into WMA9 format, but threads like this make my stomach churn

Thanks...

edit: Or for that matter, does anyone else have experience with this phenomenon?

I had no problems with added base in WMA lossless, but the fact is IT IS NOT LOSSLESS. Here's the method:

Rip WAV file from CD.
Encode in WMA Lossless format.
Open both in Cool Edit Pro 2 or other editor that handles WMA lossless.
Invert the WMA waveform, then copy.
Mix paste onto the original wave.
What SHOULD be there is a straight line.
Zoom in or increase the volume a few hundred percent. It's not.

Again, WMA Lossless IS NOT LOSSLESS.

It is very much lossless, just decode it with a program capable of decoding it correctly, one such tool is Microsoft's wmal2pcm.