Posts: 1375
From: Washington, DC
Registered: Jul 2003
posted August 29, 2008 09:24 PM
Hi.
I've had great results in re-recording stereo tracks from both DVD's and VHS's. But for some reason, my best results seem to be from VHS, although there is very little difference. Could it just be because of better magnetic tracks?
I've heard it mentioned before that DVD/digital soundtracks suffer from compression, but, as I said, the difference is minimal, and the average joe probably couldn't tell the difference.
posted September 01, 2008 02:06 AM
VHS Hi-Fi stereo is really a pretty amazing format considering that it was a retrofit to existing technology, and brought a digital dynamic range home pretty cheaply in a day when not everyone even had a CD player yet. Its main drawback is a head switching noise, which pumps up and down as the volume goes up and down and sounds like hum. On the plus side, since "speed" is oscillator-controlled, it makes sense that audio dubs work so well. First time I discovered just how speed-accurate VHS was, on an all-analog machine, I was floored.
The problem with DVD compression is that most Dolby Digital tracks have "downmix" settings that reduce the dynamic range and omit the ".1" bass effects. This enables the 6 channels to all be dumped into a Left/Right stereo configuration without running out of headroom. In other words, you have no clipping distortion, but the tradeoff is a smaller dynamic range to contain the sum total.
I think that 6-channel playback with no dynamic alteration beats VHS any day. But that's a little hard to fit on a Super 8 film!
posted September 01, 2008 08:34 AM
The best re-recording job I have ever done was from a VHS tape of 'Grease', just superb quality. But DVD is much easier to cue up.
-------------------- The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection, Elmo GS1200 f1.0 2-blade Eumig S938 Stereo f1.0 Ektar Panasonic PT-AE4000U digital pj
Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008
posted September 01, 2008 08:54 AM
Bill, I suspect that the wide dynamic range of VHS HiFi Stereo is beacause it is not a DIGITAL format subject to compression but an ANALOGUE one with FM modulation. The dynamic range (amplitude extremes) are limited only by the available bandwith, which is very extensive on this video format. Or have I got it wrong?
Martin
-------------------- Retired TV Service Engineer Ongoing interest in Telecine....
posted September 02, 2008 04:46 PM
Chip, surely you jest: how could you forget the picture? ;-)
Seriously, the tape size being proportional to quality only holds true for analog tape... wider studio tapes either yield more channels or cleaner sound without noise reduction. Martin is right -- HiFi tracks use an FM modulation, and the dynamic range is inherently decent. But the head switching noise problem has to be masked, so "companding" is used, cutting the dynamic range in half when recording and doubling it on playback -- the sound equiv. to an anamorphic squeeze.
I've redubbed from both VHS and DVD and can only say that the best source you have available is all you need. They both work.
posted September 04, 2008 12:47 PM
Most DVDs have a 5.1 option and a 2 channel stereo LR option. You need to go into your player's setup and turn off the 5.1 before doing a transfer. At that point the DVD will be superior to the VHS, as VHS Hi-Fi suffers various low frequency noise and occasional odd sounds from dropouts in the tape.