Here is a little tip. I have just finished mixing concert recording. The mixing was done in Reaper at 24bit/48kHz and now I needed to convert / downsample it to 16bit/44.1kHz. If you leave that up to black box encoders you can actually hear a change in tonality or loudness even with untrained ears. At least I noticed sometimes that inside the DAW it sounds different than what I had rendered out to 16bit/44.1kHz.

Reaper, like any other DAW, has this feature built in, however it presented me many different options on how to actually do it. I also watched an interview with Bob Katz (Loudness War fighter and author of this this awesome book on mastering
) who talked about how he used to do it.

So apparently there are multiple options and as a beginner in mixing / audio processing it was totally unclear which option would be the best. I started googling and stumbled upon this comparison website (http://src.infinitewave.ca) for SRC engines and it turned out none of the options in Reaper was on par with the pricy industry standard iZotope. In fact many of the popular DAWs don’t perform as good as that particular piece of software. (Hint: Click the help button for explanations of the graphs)

After researching some more I found out about SoX, which is an open source audio converter which is superb at sample rate conversion. It was awailable in homebrew and within a few seconds I was able to convert my 24bit/48kHz files with the following command line:

sox 24bit_48khz_infile.wav -b 16 \
16bit_44.1khz_outfile.wav rate -v -s 44100

This should correspond to the SoX VHQ Linear setting on http://src.infinitewave.ca.

Of course you can ask whether you’d actually able to hear any difference … well I’d have to do a double blind test and would probably fail but I don’t see any reason not to use the superior and free tool when I have the choice.

Also I’ve just donated a few bucks to the Sox project and I hope you’ll do the same for open source software which makes your job easier!