Recently I mixed a song down from 16 bit WAV into WMA format and sent it to several friends via email to take a listen.
One comment that came back was that when listening over speakers/monitors, the delay used on the vocals could be heard, almost as a separate entity, especially at the beginning of the song.
Apparently once past the initial part, the delay was much less noticeable.
This same person said that when he listened to it over head phones, he could not hear the delay and it (the delayed signal and the dry signal) seemed to blend well.
Question: why? Does it have something to do with the distance between the speakers and ears vs the distance between the headphones and ears?
How can I keep it from happening again?
I am forced to mix primarily over headphones (getting general levels, etc...), but then I attempt to refine the mix over the monitors.
The compression conversion from WAV to WMA shouldn't have anything to do with it, should it? We're really just talking about a different compression format, right?
Your thoughts would be greatly appreciated....
First off, Wave format is not a compressed file format, whereas WMA is a lossy type of compression (meaning part of the audio is thrown away to make the file size smaller). If you encoded the WMA files at a really low bit rate, there will certainly be some noticeable artifacts, and it won't sound as good as the Wave file. Whether or not these artifacts somehow emphasize the delay really depends on the material and the bit rate and other encoder settings.
My best guess is that the particular speakers he was listening on really emphasized those frequencies where the delay was residing, which made them more apparent. It could also be his room or listening environment.
You also said it was the beginning of the song where the delay was more noticeable. I'm guessing that's because all the instruments had not kicked in yet, so there was less going on in the mix to mask the delay.
Being able to hear the delay is not necessarily a bad thing, and in many styles they make the delay and echoes quite prominent in the mix.
However, if you want to use the delay more as ambiance, then you'll need to do some automation on the delay levels to bring them down in parts of the song where they isn't as much going on to hide the delay.
Usually, though, it's the other way around. When listening on headphones you usually hear delays and reverbs much more clearly than on speakers, so it's funny that he heard more on his speakers than on his headphones. If it was a different system he was listening on for the speakers versus the headphones, there is also a possibility that there was something wrong with his soundcard or playback software that was decoding the WMA file funny and causing it's own weird delay/echo type effect.
Basically, though, the only lesson to learn here is that it is very important to listen to your mixes on as many different systems as you can, and even in other rooms or in your car or whatever. Every system and listening environment is going to sound different, and different things will stand out or be covered up. The goal is to continue working on the mix until it sounds good on every system (easier said than done).
In addition, another lesson learned is to always double-check your music after encoding it to a different format. Listen all the way through to make sure nothing weird happened during the encoding process. Different MP3 encoders, for example, sound different from each other, even when encoding at the same settings... some work better for some songs than others... there simply isn't one that's "best" for everything. Microsoft does WMA, so there is basically only one encoder for that, but they have updated it several times, so the newest version "should" sound the best, but not always. Plus, if you encoded with the newest version, but the listener has an older version of Windows Media Player, it may not be compatible and it might not play at all, or might play with strange results.
So, always check everything on as many systems as possible, and then check your files again all the way through after encoding them to a different format (and on different computers if possible).