Re: What is the best format for audiobook
Reply #7 – 2022-01-16 08:45:55
Someone looking for respectable speech quality (not perfect, but good enough) at a very low file size I suggest...
Opus @ 13kbps NOTE: for example, Bible in a Year with Fr. Mike Schmitz is only 866MB for 6 days 7hrs 24min 32sec of speech audio at this bit rate setting. at the very least I would say Opus @ 13kbps is a good start point as I would outright avoid anything lower because the storage space savings are no where near enough to justify the fairly steep sound quality drop off as you start going lower than 13kbps down to 12kbps, to 11kbps and so on. I get opinions vary on where one draws the line, but I feel what I said here is a good ball park figure on balance of maximum storage space savings without sacrificing the sound quality TOO much. NOTE: I suspect it's possible depending on who's speaking, with their voice tone etc, it may effect quality a bit in which case one might need a bit more bit rate to clean it up. but just in my limited testing I feel 13kbps is a pretty good guideline as a bare minimum for speech on Opus. technically, I can still understand what's said going lower than 13kbps but audio quality starts to get a bit too muffled etc. I based this primarily on my Klipsch Pro-Media speakers which I feel are pretty good reasonably priced speakers for a PC. I am sure they would easily please most people. but I think with all of that said if one wants to play it a bit safer on speech quality it would not hurt to try 16kbps or 24kbps or 32kbps etc. but I think if you exceed about 32kbps or so with Opus, one is probably better off just using MP3 at a higher bit rate (say V9 (65kbps) etc) for compatibility reasons since MP3 has near universal support. because I think the whole point in using Opus over say MP3 for speech is primarily for storage space savings while maintaining passable sound quality. because as I have said before in the past... with speech, top quality is not as big of a deal as it is with music, so it's easier to make some noticeable sacrifice in sound quality (but still retains a large portion of the higher quality source files overall sound quality) for top notch storage space savings/efficiency.