Mono playback differences

[Quasipal]

As you know, if the tape is damaged, worn or recorded on earlier equipment we need to play back using the VCR's mono head. This is often used as a last resort because of perceived bad sound quality. I have been doing my own experiments and would be interested in hearing your thoughts on the matter.

Do you find that early (pre 1990) higher quality mono only decks play the mono track better than later decks?

My own findings indicate that modern stereo decks seemingly treat mono strictly as an afterthought. Placed there seemingly only as a legacy feature or for overdub work. I have used several makes (JVC, Panasonic, Sharp) and the soundtrack is rather lifeless and boomy (to my ears). Only on my older decks (Ferguson, Panasonic) does the soundtrack have a decent bass responce and some upper range treble content. I conclude that the bottom and top end are chopped off in a crude manner on the modern decks to reduce apparent fluff and hiss - but this is done much better in post processing if needed. You can see that in the frequency responce data with frequencies <100 Hz not reproduced in modern machines yet older decks show responce down to 50 Hz.

Back in the 1980's when mono is all most people had that the sound was quite acceptable, but select mono on a modern VCR and people comment about the poor sound.

Anyway, I would be interested to hear your thoughts on the matter.

[Soopafresh]

The earlier decks were very expensive, made of better parts, perhaps there was more attention paid to audio fidelity. It's been so long I can't recall. I'm amazed you have any pre 1990 units in working condition.

If you recall the TV sets in the 1980s and 1990s, the vast majority of them were equipped with a single 3.5" speaker for audio. That's just a bit larger than a tweeter. Bass? What bass? Perhaps the more affordable decks of the 90s were designed to match the frequency response of that crappy TV speaker. Just guessing.

There are quite a few audio processing utilities which can restore some of the life to those old VHS tapes. BBE Sonic and Harmonic maximizers can bring back/synthesize some of the lost audio frequencies. It all depends on the source.

There's always the option of capturing the tape to PC, cleaning up the audio and video, then playing the digital copy on either a DVD player or a media player such as the WD TV Live.

[Quasipal]

Thanks. Well keeping them running is a labour of love. New caps are often needed (upgrade to audiophile type) but not much else to do but cleaning and alignment cheks. My last Panasonic deck came from the estate of an old lady who passed over and although the PSU was dried out (making for capstan motor noise) I don't think she had played more than one or two tapes. That was a 1989 machine and plays pre-cert films with a rock-solid picture. Those early tapes have a thicker binder and I love the way the older machines ride any damaged sections.

[robjv1]

This is an interesting topic. I have had several of the lauded JVC SVHS decks and I noticed that the JVC-SR7600u I had had really crummy mono audio, with the JVC SR-V101US being a step up from there.

The JVC SR-W5U sounds a lot better than both of them though, with a lot more treble and much less noise -- easily the best deck I have for mono tapes (I have a Panasonic deck and a later-model Sony) I don't have any pre 1990 VCRs to test, but I'd be curious to see what you learn in your other tests.

[Quasipal]

I have been continuing my tests. Slightly off-topic I was recalling my movie rentalals from the late 1980's and early 1990's (all on mono VCR's) and never remember sound quality (even through our decent TV) being an issue, however on recent consumer VCR's with mono selected the sound quality from many tapes - either pre-recorded or from other decks is downright horrible. Sound quality is often distant and muddy with absolutely no presence. OK, down to my findings - using tapes "The Best Of Jean-Michel Jarre" and "The Best Of The Eurythmics" and one tape recorded on a Ferguson Videostar in the 1980's.

Panasonic NV-HS1000: Sound quality passable, and with a slight treble boost was useable, however low frequency hiss was pronounced.
Panasonic NV-HS930: Sound quality distinctly 'afterthought' with little in the way of treble or real bass.
Panasonic NVJ35: 1989 mono deck - plays tapes well with bass and treble. Some variation though in quality across tapes with some better than others.
JVC SR-S388E: The best of the lot with very crisp and clear mono sound.

The difference in audio quality across these machines was huge - with the worst needing much EQ-ing to get it decent and the best needing nothing apart from perhaps light filtering.

I tried some other consumer VCR's, but really, the sound was not worth mentioning. I will add that if you record on the consumer machines and play the same tape back, then the sound is fine.

The JVC also played back the most stable Hi-Fi sound with the least sputter, however the Panasonic NV-HS930 had the best quality stereo sound with a better balance of bass and treble (almost like playing a CD). My findings not only reinforce what LordSmurf says about needing multiple VCR's it also tells me that anyone just choosing one VCR to do their restoration will not be getting the best transfers.

[robjv1]

Sad but true. I really should think about picking up some EQ equipment so that I could do it while it's transferring. At this point, I have so many tapes left to convert and make such a fuss over the video/audio quality that it's progressing at a snails pace. The SR-W5U does a good enough job overall to satisfy me, but I could use some ancillary equipment for a few old home movie tapes.

[netmask56]

Sad but true. I really should think about picking up some EQ equipment so that I could do it while it's transferring. At this point, I have so many tapes left to convert and make such a fuss over the video/audio quality that it's progressing at a snails pace. The SR-W5U does a good enough job overall to satisfy me, but I could use some ancillary equipment for a few old home movie tapes.

Rather than trying to EQ on the run whilst transferring - you could easily overload the audio causing distortion, it is a better strategy to simply do 1 to 1 transfers and then EQ on the computer. There are several free wav editors like Audacity that can do fairly complex audio restoration. A clue on plugins - use"harmonic exciters" in preference to standard treble boost and the like - you get a better subjective result without bring up tape hiss noise.