I took me quite a while to figure this one out... Note that I use Adobe Audition as my sound processing program - if you don't you can probably skip the rest of this post.
When listening to my tracks on my phone, I would sometimes hear a loud pop at - what I thought was - the start of a new track. I don't hear it when playing on my home audio system AFAIK - but I haven't run exhaustive tests with that end of the system...
I decided to get to the bottom of it for my phone playlist and started reviewing the "defective" track with the program I use to "rip" CDs or simply clean up my own home recording. The first thing I noticed was that I never heard it for tracks I ripped from CDs, only my own recordings and tracks I would rip from LPs I have.
But I couldn't find any weird artifacts at the start of these tracks (I found a few but they didn't correlate to what I was hearing). Digging further, I eventually figured out that these pops were NOT at the start of a track, but at the end of the previous track. If you hear similar pops, here is a simple test - play an album (all tracks) - note when you hear these "starting" pop (I bet they'll be between tracks that belong to a set - I.e. in classical terms between mvt 2 and 3, 3 and 4, etc but NOT at the start of mvt 1 or 2 and NOT between the last mvt of a piece and the next piece in the set. Aha!
The pop is in fact NOT at the start of any track but at the end of the preceding one. Sure enough, when I started scanning through my tracks, I would find odd artifacts at then end of some tracks - always mvt 2, 3, etc. of a piece, but NEVER at the start of the fistt or last mvt and (almost) NEVER in a piece in one single track. Digging through Adobe Audition 3 (the last desktop version) help and forums, I discovered references to Markers and Play List. While the information available is skimpy - at best - I now believe that these loud pops in MMA (which I can see in the Adobe Audition UI) are in fact "markers" that Adobe inserted into tracks to form "playlists" whereas the system would play all movements of a sonata or concerto together.
Great Idea - awful implementation.
Note that playing together tracks that belong to one musical piece is a request I have seen on the MMW/MMA forum. It certainly would be very useful to hear all movements of a classical piece together rather than each movement as they get picked up in the random shuffle. While I love Adobe Audition (based on the old Syntrillium CollEdit program) for its ability to clean up noise and clicks/pops from recording, Adobe's implementation of playlist was atrocious - I'm just glad I figured it out and can now manually edit all these tracks to remove these markers (hoping Audition won't try and re-insert them....)
21:12 Edit - My initial post referred to pops at the end of mvt 1, 2, etc. but Adobe's implementation was more complicated and these pops would happen at the end of mvt 2, 3 etc. until the mvt before the last. If a piece had 5 movements, Adobe would place these markers at the end of all the "inner movements" - i.e. 2, 3 and 4, but not at the end of the first or last movements. Ar least as far as I can tell - to my knowledge none of this is documented...
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