Why is the sound of VHS tape so good ??

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cjacek

cjacek

Analogue Enthusiast
I REALLY would like to know, in some detail if I may, why, when recording directly from my mixer to my Hi-Fi VCR, the sound captured on a VHS tape is FAR superior to even the best cassette deck and why it's called "a poor man's DAT" ?? I was looking at my VCR's specs and nothing was as spectacular as looking at a reel to reel specs or ADAT but, damn, that VCR records some high quality sounds. Definitely CD quality and perhaps better ? From the specs I wouldn't be able to predict. Why, in real world applications, does a Hi-Fi VCR record to such high quality ? Also, my mixer's "headroom" is much larger than my VCR's, based on the specs, and so I wonder why my VCR doesn't distort much ? Ok, I'm stupid, please explain.

Thanks as always,

Daniel
 
This is a bit like asking: How to highly polished things become so highly polished?
The answer is of course "because they are highly polished". :)

HiFI VHS uses a stereo analog sound format. It's better than casette tape for the exact same reasons that 1/4" tape is better than HiFi VHS, it uses more tape area per second, to put it simply. HiFi VHS does that by recording the sound with a rotating head, just like they record the video. The specs are close to CD, yes, >80db as compared to the 96db of CD, but that's all theoretical stuff anyway.
 
If I recall, VHS Hi Fi also uses a noise reduction system similar to DBX.(?) The s/n and frequency response is very good, but there are also issues with tracking in (not 100% sure on this) the N/R system that can have odd distortions on highs/transients.
I remember having strong transients crap out, regardless of level, or how many times I had the deck 'aligned'.:)
On the other hand, it seems to work great on finished music. Maybe that's because most of the biger spikes have been tamed.
Wayne
 
Yes, that's true, those 80db is after noise reduction, and the NR will color teh sound, of course. Not necessarily badly, though, my Yamaha 4-track had dbx noise reduction, and that machine sounded excellent, especially when you pushed the tape really hard. :)
 
but...

I remember hearing that hifi tracks have a very
high harmonic distortion - around 5% THD
if I recall. It does have a high dynamic range,
but it embeds the hifi audio track into the
video stream by doing some complicated modulation
scheme..
It's been a while since I tested this,
but I remember being less than satisfied when
I recorded an audio CD onto a hifi VHS (an expensive
sony editing quality consumer deck) and being
disappointed in the results.. ?
 
I think if you look under the hood of a VHS deck, you'll find the playback head covers only a very small area of the tape surface - something like 10% - the rest being allocated to the scanning video head, so tape width has nothing to do with it, I imagine.
 
robin watson said:
I think if you look under the hood of a VHS deck, you'll find the playback head covers only a very small area of the tape surface - something like 10% - the rest being allocated to the scanning video head, so tape width has nothing to do with it, I imagine.
Click to expand...

Damn, thanks for bringing this very, very old thread back from the dead! :eek: I feel so freakin' silly, especially when my thoughts on the subject are completely different now. :rolleyes:

~Daniel ;)
 
Woops, I feel pretty silly posting on such an old thread. Suprised to find you lurking about here still!
 
robin watson said:
Woops, I feel pretty silly posting on such an old thread. Suprised to find you lurking about here still!
Click to expand...

No problem about the posting my friend .. :)

I usually post on the Analog Only forum. See you there perhaps ? ;)

~Daniel
 
I few years ago I guess VHS could help to poor folks. But you can pickup a consumer CDR for about $200.00 and get them used off ebay for $75.00.
 
More than one way to stick audio on VHS :)

You're correct that there is a narrow strip reserved for audio on the edge of a VHS tape,
but that's for the older plain stereo format audio - fairly low quality, probably
worse than audio cassette since the tape speed is so slow.
The HiFi audio is mixed in with the Video stream and put down "inside" the video information using the rotating video head. Much better than the linear, but
nowhere near CD quality..
I was surprised to see an email about this too!
Cheers,
Gord Wait
 
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