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Hey everyone,
I am attempting to convert some old live recordings from cassette tape to digital format. I have recorded them into the computer, and now I am working on sweetening the audio quality as much as possible.
The issue isn't the tape hiss, its mainly just poor sound quality. The recording is very muddy, almost like a pillow was over the mic.

I have tried using the iZotope mastering compressor plugin in Soundforge 9, and that helped a bit, but to get a good/brighter/cleaner result it overcompresses the bass and I lose the definition of the bassline (I'm the bass player so that's unacceptable!)

Do any of you have any suggestions how to brighten the sound, or strip out the mud?

Thanks!

Comments

jonyoung Thu, 01/28/2010 - 08:57

Why not try an EQ solution instead of compression? A good phase linear EQ can do wonders to strip the haze off a mix. A cassette isn't going to have much low end to begin with, so you can boost the bottom with a tight notch, cut the low mid boxiness out, and a broader boost of the upper mids. Balance the EQ first, then compress if you want to.

djmukilteo Thu, 01/28/2010 - 11:37

I have used SoundSoap on cassette tapes in the past and to me it was a good starting point to apply to the file. If you set it properly it will clear up the sound and lower your noise floor and give you a bit of headroom to work with. I'm not pushing SoundSoap but any noise suppression/reduction plugin you have should help.
Start with that and expand the whole thing the best you can.
Then work on the overall sound next with some well placed EQ's followed up by a good final compression and add gain back.
You can always record that series and then start again with some more expansion, EQ etc.

JoeH Fri, 01/29/2010 - 18:59

Stop with all the computer gadgets and fix-its for now, and consider the source itself: the tape and the playback head.

If you're playing back on the same deck that you recorded it may be just a cleaning & some alignment that's needed. If you're working with two different machines, consider the following...

My guess is your playback head is out of alignment to what the original recording head put down on the tape. This is a very old and very common problem with cassette standards. In a nutshell, there really wasn't any standards. Oh sure, they tried; there are even STL tapes out there that will at least get you in the ballpark, but it was damn near impossible to ever create a standard that the world could agree on for PB Level, Azimuth and EQ. You could always get CLOSE, but not quite....and this is with GOOD, 3-head equipment; we're not even talking about consumer gear with PB and REC using the same heads.

With slow track speed, narrow track widths and tolerances so tight for cassettes, it was nearly impossible to get beyond all but the basics of alignment. (The Nakamichi Dragon was a great machine, as long as you recorded/played back the tapes on the same machine, you were ok. Forgettaboutit when it came to playing those tapes on other machines, including well-maintained Tascam 122's and so on. THey NEVER sounded good from one machine to another.)

And we won't even get into wow & flutter or pitch/speed problems with cassettes. Oiy!

For cassette alignments in the 70's, 80's and early 90's, I tried to create a one-size fits all standard for my machines and my client's machines. This worked fine until I ran into a client who had HUNDREDS of tapes of his own, recorded all on his own machine, that frankly sounded GREAT when played on his machine. Unfortunately, anything WE gave him sounded like crap (and not unlike the pillow-over-the-mic analogy you used!) It was pointless to get him to change, and ruin the playback quality of his existing library if we tweaked his machine to OUR standards. In the end, I was able to get his machine in for an evaluation, along with three or four of his best tapes. I then used one of these tapes and dedicated a machine at my own place for this client's dupe projects only, and (you guessed it!) aligned this machine ONLY to match his machine and tapes. Problem solved, until he moved on to DATs and CDrs in the years since.

But getting back to your problem/issue, I would get yourself a good reliable Cassette deck that you don't mind using as your 'experimental" machine and begin some testing and azimuth alignment. Clean & demag the tape path, make a tape that you like that sounds OK, then mark it and put it away as your baseline for what the thing did when it was "new".

Then, you'll probably need to remove the tape cover/housing to get access to the head stack, and one of severl miniature screw drivers (usually a very small phillips head, although the Tascam 122's and other machines had a hex head that required a special skinny-shafted tool to reach in to the area to get to the alignment screw assembly on the LH side. When playing back either test tones or the recorded material you're having problems with, GENTLY, and slowly turn the alignment screw a bit in either direction, to see if the problem gets better or worse. (Never go more than a few turns in either direction; you could really mess it up otherwise....) You can also use an oscilloscope if you're handy with that sort of thing.

You may also need to do some SERIOUS cleaning of the playback head, as well as some de-magnetizing of all the metal parts that come in contact with the tape and tape path. If you're comfortable with all of the above, the steps are thus: Clean & Demag all tape path & heads. Load up an alignment tape and get the best results possible for the age/condition of your machine.

After you're done all that, try the original "Muffled pillow" tape in question, and see if it gets any better. If not, you can try the azimuth alignment trick again, just to see if it brightens up any.....

In a worst-case scenario, your cassettes may also be shedding oxide, and may need to be baked, just like its open-reeled big-brothers. If you need more info on this and other analog tape tips & tricks, take a few moments and visit Eddie Ciletti's website at: [[url=http://[/URL]="http://www.tangible…"]Eddie Ciletti: From Digital Audio to Vacuum Tubes![/]="http://www.tangible…"]Eddie Ciletti: From Digital Audio to Vacuum Tubes![/] There's a lot of good stuff on there about analog tape, tape baking, alignment, and so on.

Good luck with this one! I hope that helps you somewhat.

RemyRAD Sun, 01/31/2010 - 21:30

Turn off the Dolby button. Transfer the cassettes again. You can fix the noise in software. Easier to fix the noise than to eliminate Dolby mud & miss tracking. I have a dedicated cheap Sony deck that I can tweak head azimuth on for best high frequency playback results. Screw with the screw while playing a tape and listening to the left and right channels combined. When you hear your maximum high frequencies come up, you're there man. Test tapes really don't help when dealing with cassette tape shells. The shells ultimately affect azimuth. Better you should remove the tape from the cassette shell and build up a 1/8 inch reel to reel recorder for ultimate playback. You think I'm kidding? No way.

Miss Tracking a.k.a.
Mx. Remy Ann David

JoeH Wed, 02/03/2010 - 07:46

Great followup, Remy....I TOTALLY forgot about summing to mono and listening for the best/brightest stuff when turning the screw. Shows you how old I'm getting....forgetting stuff like that, although that's exactly what I've done so many times, after all the alignment stuff I mentioned. In the end, it's just best to turn off all the techie stuff and go with what you're hearing. I can't remember the last time I RECORDED onto a cassette, but I still get things to transfer all the time, and it's "by any means necessary" to get the best level and top end off a cassette.

Dolby and DBX never play back the same way twice on any cassette deck, and that too is usually the first thing I turn off when checking PB levels and EQ. I don't think we mentioned the PB EQ switch, if his deck even has one? I usually set that to the "Normal" tape setting as well, even though many tapes are Crome. (We didn't talk about bias current settings, either...it's possible his deck wasn't/isn't set up properly for the tape he's using, and he COULD be erasing the hi end as fast as he's recording it....)

And yep; cheap shells are/were murder. When someone gives me a bad cassette to transfer, the first thing I do is crack it open and put the the tape & hubs into a precision casing, with removable screws, better tape guides and friction plastic between the sides. Someone told me a long time ago that the easiest/quickest way to guage a cassette's quality was to look at the case: No screws (just sealed plastic) meant junk, and 5 mini-screws meant there was at least a fighting chance to get some quality out of the damn thing.

So many reasons to hate cassettes. (And don't even get me STARTED on vinyl.) :frown:

anonymous Sat, 02/20/2010 - 16:36

EQ ended up working fairly well...

Thanks to everyone who responded with your suggestions!

I had actually sent the tapes to a guy who did all the transferring to WAV files for me. I am not sure what equipment he is using, but he did a pretty nice job of removing most of the hiss and noise.

I will pass along your suggestions for cleaning, head alignment and Dolby options.

The tapes were basically live practice sessions recorded into a small boombox, so the quality was pretty bad going in from the get-go. To make matters worse, we were using some cheap cassettes and a couple decent (5 screw) ones, so the quality ranges from pretty bad to really bad...

I am pretty sure he did not remove the shell and wind onto reel to reel, but that is very interesting that the shell and screws can affect the sound that much...

Anyway, after lots of hours messing with this in Soundforge, the iZotope compressor did ok on some things, but Ive ended up using the iZotope mastering EQ on the majority of it.

RE jonyoung: You must have done this before :cool:

RE JoeH: - Speaking of hatred for cassettes, I can't wait to throw all these damn things away!

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