remove clipping?

[kash]

My band is currently in the writing process and I used an old tapedeck to record a working track. Problem is, the level indicator doesn't work on the tapedeck, so I didn't know it was too high and clipping the whole time. Is there an easy way to remove the clipping? I've tried running a "use average" noise reduction and then a pop/click removal with low tolerance after that, but still can't get the clipping noises to go away.

[piano nick]

Is there an easy way to remove the clipping? I've tried running a "use average" noise reduction and then a pop/click removal with low tolerance after that, but still can't get the clipping noises to go away.

In a word, the answer is NO. The problem with an "average" noise reduction may be that every point of clipping is different (audio peaks vary all over the map so to speak).

You could spend hours fiddling with the files; my guess is that you could record it all over again in less time and get much better results.

There is an old expression, "you can't make a silk purse out of a sow's ear". It's one that should be kept in mind for audio work.



PN

[Blandine Catastrophe]

You can try to apply a bandpass filter to keep only the frequecies effectively recorded from the source, filter properly the hiss noise, and compress to reduce, not the clipping, bur the sensation of clipping. The settings depend much on the audio you get, so you must try different settings and adjust them. But basically, you will still get a clipped audio.
The smoother can sometimes reduces the clipping sensation, but it is no more a miracle solution.

[DougDbug]

Here's the deal...

When the waveform is clipped, the "waves" are chopped-off. The data/information that was chopped-off is missing, and there's no way to know how high the wave peak was, or the shape of the wave. I'm not sure if there is any "un-clipping" software, but it cannot work perfectly. (GoldWave does not have anything like that.)

The chopped-off waves generate nasty harmonic distortion, and they cause compression by limiting the volume. Analog tape (I assume it's an analog recorder) is more forgiving than digital recording, because the waves are rounded-off rather than squared-off. (The same is true of tube amps. They tend to clip more "softly" than solid state amps.)

I'm with Nick. Get the band back together, get your hands on some better equipment, and try again. You might be better-off recording directly to the computer's sound card... It's hard to say, since I don't know anything about your equipment. (I assume you have zero budget ).

Are you using a mixer? If so, you should be able to "calibrate" the mixer's VU meters to the recording levels with a little trial-and-error. You don't need the band for the calibration experiments, you can use a CD for that. If you don't have an extra mixer, you can pick-up a cheap one for under $100. If you happen to have a 4-channel tape recorder, two stereo mixers might be cheaper than one 4-output mixer.

[piano nick]

Doug's first sentence said it all. I'll offer an analogy:

Suppose you buy a pair of pants, and think they're too long. So you cut of twelve inches, only to discover that they weren't too long after all.

The problem is that in the meantime, you've burned the cut-offs. Even if you had the pieces you cut off, there would be an ugly seam.

What you've done is cut the "legs" off your waves, and thrown them away.

That's what clipping is.

[bgiblet]

Provided it's possible to get the group to do it again, I think Dougdbug is right about trying direct to digital recording. The recording you've got is screwed, blued, and tattoed. If the tape deck is old enough for the meters not to work, it begs the question,"what else could be wrong with it?"

Answer : Lots of stuff! Belts, rollers, head wear, head alignment, speed problems, tape hiss, none of which you get with digital. I worked in a hifi service shop in an earlier life and spent many happy hours chasing down stubborn tape transport problems.

You can get a cable at almost any audio store(maybe the lumber yard now) to connect two RCA jacks to a stereo mini phone plug. If you've got Goldwave on a computer with a sound card already, hook it up, practice a bit, and Bob's Your Uncle. Goldwave has nifty level displays, and even if you set the level a little on the low side, the noise floor is so much lower than the tape, you probably won't be able to hear it.

-BG

[slacker]

Sony has a noise reduction plugin which includes clipped peak restoration. I use it often when editing sporting event video. I couldn't live without it. Actually rebuilds the peaks through a sophisticated algorithm.