VHS capturing audio issues

[Cyberrock]

I'm capturing a few old home videos from VHS cassettes. For most of the time the sound is quite low, and now and then is gets much louder and also sounds better. Anyone that has run into this problem? Any ideas on how to solve it?

These where recorded on a VCR (circa 1988-1989) with a special feature with two sound modes. One standard and one that improved the sound somewhat. Unfortunately I don't remember the details. Could this be the problem? Anyone remember these and know what this could have been?

(I'm set in Europe, Sweden, and these are PAL VHS, but I do not think this issue should be exclusive for PAL, nor the VCR type.)

Thanks for any suggestions on how to solve this!

[jagabo]

Linear audio track (recorded linearly at the edge of the tape, low bandwidth, low signal to noise ratio, mono) vs. Hi-Fi (recorded along with the video by the flying heads, much more bandwidth, high signal to noise ratio, stereo) audio track. If it's recorded on the linear track you can't get Hi-Fi out of it. Be sure you're using a Hi-Fi deck for playback. Otherwise you'll only get the linear track (the linear track is always present).

[Cyberrock]

Thanks for your reply. This might very well be the issue, however I use Hi-Fi VCR (tried 2 of them) and the audio seems to be using one or the other (mostly the "low volume") and I get quite bad sound issues when it's now and then switches between them.
The VCR used to record this tape is dead since long ago (no wonder since it was from 1988), is there any way to deal with this?
It's one of those fond memories that I'd really love to capture for the future but these sound issues are kind of ruining it.
I'm grateful for any suggestions!

[jagabo]

Thanks for your reply. This might very well be the issue, however I use Hi-Fi VCR (tried 2 of them) and the audio seems to be using one or the other

If there is only a mono track that's all that gets played no matter what deck you have. A Hi-Fi deck will play the Hi-Fi track if there is one -- unless you force the player to play the mono track instead (there's usually an audio option for that on Hi-Fi decks). If your tapes have no Hi-Fi track you're stuck with mono.

You can always increase the volume in software. You can also try a graphic equalizer to bring out more high frequencies. But you can only do that a bit before the hiss is overwhelming. Maybe you should post a short sample video.

[lordsmurf]

You can download custom EQ filters for Sound Forge
at http://www.digitalFAQ.com/forum/showthread.php/soundforge-audio-filter-1605.html
And you'll probably need to read the Sound Forge audio filtering guide.

There are a few paragraphic EQ filters called "High Restore"
And a few graphic EQ filters called "Enrich"

These will augment your audio to emulate HiFi and de-muffle the quality. They work VERY well.

You'll normalize the audio to correct gain (loudness/volume).

I use a mixer board (hardware) to pre-process audio. Further processing is done in software.
That can make a big difference, too.