Subject:Remastering A 20 Year Old Cassette Tape

Posted by: WhoDoYouThink

Date:7/16/2004 9:55:53 PM

What do I need to do to remaster a 20 year old cassette tape?
The left channel is almost completely gone and the right channel is muffled a bit. I'd like to get rid of the left channel "hiss" and maintain the integrity of the tape (not over compressing it etc...).

Any ideas?

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: WhoDoYouThink

Date:7/16/2004 9:56:39 PM

BTW, the tape is a recording of a radio station (Summer '84) and was recorded on a crappy Magnavox boombox.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: Rednroll

Date:7/16/2004 10:04:16 PM

The Sony Noise Reduction plugin will be your best friend in getting the best results. Don't forget to clean your cassette tape head also before attempting to play it back, with some alcohol. A 20 year old cassette, might be a little brittle and will probably dirty up the tape head quite a bit, so clean that head after each playback.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: drbam

Date:7/17/2004 7:06:08 AM

From your description of the tape and original recording, I would suggest to keep your expectations quite low.

drbam

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: WhoDoYouThink

Date:7/17/2004 11:35:24 AM

Oh yes...My expectations are quite low. I just wanna get this bad boy on
CD before it wastes away to nothing.

Thanks for your help.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: RiRo

Date:7/17/2004 3:59:29 PM

Being a radio hack from that era... here is my guess. The aircheck is mono... thus one side being much hotter than the other. Take the hot one and nix the other. Wanting to preserve the original dynamics is nice... but if it was radio from the competitive markets of 20 years ago... It has no dynamics to speak of, if it was recorded on the air monitor. If it was from the program channel... it is flat and lifeless.

Listen to the tape. Record it into the box with the levels right , etc.

De-noise (SoFo Noise Reduction) and work from there. I have tons of tapes just like that... they can be helped... but they will never sound like new stuff.

RiRo

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: hat3k

Date:7/17/2004 7:17:39 PM

fully agree... never...

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: WhoDoYouThink

Date:7/18/2004 10:35:30 AM

Actually, the tape was recorded in stereo but the left channel is barely audible. I'm pretty sure the boombox that I recorded it on is the culprit.
Sometimes it's there, sometimes it drops out.

I may just nix the whole left channel like you said.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: Hummingbird

Date:7/20/2004 6:31:03 AM

I had a project like yours some time ago. Let me suggest that you follow Rednroll's advice and clean your playback head, then record the entire tape into SoundForge as it is. Save this as your "original." Then, working on what will become one or more "copies," experiment with noise reduction, EQ, or whatever processes/functions you want, trying to improve on what you have. Like the others have said, don't expect miracles, but I think you can probably improve on the quality of the recording as it now exists. Just remember not to save over your original.

Hummingbird

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: Chaim

Date:7/20/2004 4:57:00 PM

I've been working on some really beatup sound files lately, and I find that noise reduction helps a lot if you noise print a portion of the file (even a pretty SMALL selection) that consists entirely of background noise. Reducing noise by up to 20db is fairly artifact free. Secondly, I'm guessing you could benefit from the Effects-Dynamic-Multiband filter using the "De-ess" preset, perhaps two or three passes. Like the others have said- experiment. I'd be interested in hearing what worked the best.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: LightMfg

Date:7/21/2004 4:08:20 PM

All of these suggestions are great; the radio guy is right though, even if was RECORDED in stereo it was likely broadcast in mono (or very near mono as FM separation isn't much more than about 35dB anyway) so whatever channel sounds best could probably be used. At least you can copy bits from the good channel to the bad one only when the bad channel "goes away" - this preserves as much stereo as possible.
As a cassette manufacturing engineer for over 20 years, I would strongly suggest that if this tape is valuable enough to salvage that you actually open the cassette shell and move the tape reels into a new shell.
The reason for this is that cassette shells are pretty cheap and they have a tremendous influence on the way that the tape moves across the tape head;this greatly affects the playback sound of a cassette. If the shell itself is even unoticably warped, the tape would play badly. Also, inside the shell is a tiny but VERY IMPORTANT piece just at the middle of the opening in the shell called a "pressure pad" - this a piece of felt glued to small strip of non-magnetic spring alloy that keeps the tape in contact with the head as it moves; usually on 20 year old shell, the glue has dried out or pad itself is disintegrated- this may be the cause of your lousy sound. And lastly, inside the shell there SHOULD BE a paper or mylar liner just inside each side of the shell - many shells either don't have these or they are worn out (all of this is trebly true if this cassette spent much of it's life in a car).
Just go out and buy a good "5 screw" shell, that is a shell with screws instead of the sonic welded variety, carefully take apart the new tape, lift the top off, make a little drawing of how the tape threads through the pins and rollers (it's not very complicated, much easier than VHS), throw away the spools of tape; make sure that your valuable tape is wound to the leader on either end, take apart it's shell, hopefully it's screw shell but if not, it's usualy not too hard to crack them open by pulling it apart at the opening where the tape rolls through, be careful not to spill the tape everywhere if you try this (I HAVE spent 2 hours spooling an important tape onto a reel by hand - NO FUN!!) or you can use a largish pair of needlenose pliers stuck in the opening and open the pliers instead of squeesing them shut, if you sort-of work back and forth across the opening you can usually open them gently, put the old tape into the new shell, be careful when putting the top back on to keep a little tension on the two reels with your fingertips so that the tape doesn't get slack and then get pinched in the new shell, put the screws back in and then turn the take-up hub and watch that the tape runs smoothly and very flat through the opening, if it does not take it apart and double check your positioning and try again, I have done this routinely for years and salvaged many a lousy tape.
In a nutshell, tape playback is a MECHANICAL process and the position and geometry of the tape passing over the head MUST be correct for to sound like anything but absolute CRAP! SF can only do so much and you will get MUCH better results with good playback from the deck; this will save many hours of "turd polishing"...

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: Geoff_Wood

Date:7/22/2004 3:38:52 PM

... and once you've resued it, write it to audio CD and CD-ROM as a wav. May eb worthwhile also producing a cassette copy - the more backup formats the better, if it is of value.

geoff

Subject:Head alignment may be off too.

Reply by: farss

Date:7/24/2004 4:15:57 PM

Years since I've played with the innards of cassette decks but I do remember being able to get better results at times by playing with head tracking and azimuth. Mind you you may have a big issue getting it back right after you've tweaked it to suit the tape.

Bob.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: BobMarvin

Date:8/1/2004 11:26:30 AM

It sounds as if you have a head alignment issue. If you ahve a way to try differemt playback devives you just might find one with closer head alignment charateristics to the machine your tape was recorded on. If you know someone with a bit of technical ability, they may be able to make the adjustments to your playback device temporarily so that you can make a decent dub.

Subject:RE: Remastering A 20 Year Old Cassette Tape

Reply by: DouglasClark

Date:8/15/2004 5:53:20 PM

To give you some ideas, I just did a 1978 beach rock concert cassette to CD restoration for the drummer in the band. The cassette was recorded in the audience, and was in OK physical condition, but the sound was very "wooly", not to mention hissy. I gave up on Sony Noise Reduction because there were no "noise only" parts on the recording, and trying to get rid of the hiss with NR also took away too much of the highhat and cymbals...which my drummer client wanted preserved. So I tried Ozone instead. Judicious notching in Ozone's EQ, a bit of multiband exciter, a touch of reverb, multiband dynamics to put a little life in the bass end, and a bit of stereo widening on the upper midrange and 1 ms phase shift to one side (to move the cymbals off center).

Well, it didn't suddenly turn into a golden recording, but it did put a little life back into it...and the client was happy when he heard the A/B comparisons to the original cassette. (And I finally learned what most of the controls do in Ozone! Rather a sophisticated little plugin, I must say.)

You could try some similar treatment with Sony's plugins. (but I don't think there is a similar exciter or stereo widener in the SF/Vegas plugin collection).

I'm going to look for a cassette deck with adjustable head azimuth if this guy comes back with more cassettes. I suspect that tuning the head alignment to the cassette could help a bit, as mentioned by others.

Subject:RE: Head alignment may be off too.

Reply by: DouglasClark

Date:8/16/2004 7:14:54 AM

Bob, I've never done head alignment, but I recall that you need a test cassette with calibrated signals recorded on it. Do you know where to get such an alignment cassette, and/or where I could find general instructions for playback head alignment?

Douglas