I’ve got a VHS master tape from which I need to create many VHS dubs. (I intend to use 2 consumer-quality VHS decks connected by RCA plugs).
The audio on the master tape is “distorted” (my term; I think the official term might be “overmodulated,” but I could be wrong there). Basically, as the audio volume approaches anything near loud, it gets “buzzy.”
Lowering the playback volume helps somewhat, but then the softer portions of the soundtrack get lost.
Fiddling with the bass and treble adjustments on the playback TV yeilded marginal, if any, improvement (at least to my ears).
Any advice, without sending me to some $1000/hr sound studio? Thanks in advance.
go buy (rent?) a compressor/limiter. It’s kind of an automatic volume control. It will basically turn the volume up when it gets quiet and turn it down when it gets loud. Depending on the quality you need you can get them pretty cheap at music stores.
I’m a video professional (that is, my specialty is pictures, not audio), but I obviously work with a lot of sound as well, even though the final work is done by professional audio mixers. Unfortunately, there is no real fix for overmodulated audio. Once the source is recorded like that, you can play with volume levels and maybe add some compression to take the edge off, but that buzz will always be there. There may be some audio folks out there that can contradict me, but when we get overmodulated audio, our sound guys usually have us re-record, use a different take, etc.
filmyak, would you be so kind as to e-mail me?
Cartooniverse.
I’m an audio professional, and filmyak is correct. I can’t be fixed. The term is “saturated”, though “over-modulated” works too. It may have happened during the original sound recording, or when your copy of the tape was made. If the latter is true, you may be able to find another copy that doesn’t have the problem.
A compressor may reduce the apparent problem, but not eliminate it.
Also, how many copies? I suggest using a professional tape duplicating service, where they can make a hundred or more copies from one pass of the tape. The tape will degrade slightly evey time it passes over the playback heads.
The problem is that when the tape is saturated, or there is some other amplitude limiting process in the recording, harmonics of the original frequencies are generated on the tape. So for a tone having a fundamental frequency of 100 Hz with its natural overtones from the instrument, additional and unnatural harmonic multipliers of 100 Hz are created and you can’t filter them out because they are in the normal audio pass band of the equipment.