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View Full Version : Aligning CD sector boundaries best practices


ledwhofloyd
2026-04-01, 09:33 PM
Audio tracks must be cut at the sector boundaries if they are to be burned to CDs to prevent clicks. The sector boundaries occur every 1/75 sec, or 588 samples (because the sampling frequency standard for CDs is 44.1 kHz). If the audio tracks are not cut at the sector boundaries, they will play perfectly fine on a computer. We cut tracks at the sector boundaries simply as a courtesy for people who do burn CDs.

With this in mind, there are 2 scenarios that bother me.

1) Let's say somebody forgets to cut only a couple of tracks that are in the middle of a fileset at sector boundaries. Or maybe you needed to edit a few tracks in the middle of a fileset, which added or removed a little bit of audio, and then you want to adjust the tracking to align with the sector boundaries. The proper way to do it is to realign EVERY track in the fileset following the ones with the sector boundary errors.

I've seen people only fix the tracks in the middle of a fileset that had sector boundary errors. This adds a gap at the end of the last track that you fixed, breaking the continuity of the fileset. Please don't do this.

2) Say you have a clear break in the audio, for example due to a tape flip. In this scenario, the tracks before the break are not cut at the sector boundaries and you want to fix this. However, you want the audio track immediately after the clean break to actually start with the audio after the break. You probably don't want the boundaries of the tracks before and after the clean break to be shifted. In this case, you should align the sector boundaries of the tracks before the clear break, and then separately align the sector boundaries of the tracks after the clear break. This will pad the file immediately before the clear break, but it will prevent any tiny bits of audio around the break from ending up on the wrong track.

dorrcoq
2026-04-03, 06:10 PM
Use CD Wave, no sector boundary issues. Ever.

Audioarchivist
2026-04-08, 04:34 PM
In Trader's Little Helper, there's options to fix SBE's, with something like "add to next track" being the best option for us and our gapless needs... Going from memory and I'm kinda foggy today so forgive me.

When I'm doing tracking of a file, I like to do my cuts on the whole full second marks with no fractions. That way, I'm on the "one" of that 75 frames per second sector CD stuff and there's no issues... Except for that one time I messed up and cut something wrong in the middle. TLH caught it, and did the fix...

As far as how much it moves to bump those samples from beginning to end and over to the beginning of the next track down the line, possibly screwing up the beginnings of the tracks in your scenario, the amount is very small - a fraction of 1/75th of a second! That's a pretty small fraction. I guess, if there were some kind of EXTREMELY defined break, there might be a tiny blip added to the beginning of it, but then, that isn't quite a gapless playback in the first place... End to end it will still playback to sound the same.