Audacity Forum

I edit music from LP disks with Audacity 1.2.4 OK and SAVE the result OK and re-open it OK. The waveform is normal, with maxima about 2/3 of the linear scale. When, however, I EXPORT AS WAVE and re-import it, the waveform is clipped, pressed against the top and bottom of the window. If I greatly attenuate the waveform and try it, I can export and import it OK. Sometimes the clipping doesn't occur.

<<<I edit music from LP disks>>>

But not capture the music from LP disks? No USB turntable? That's moderately important.

<<<Audacity 1.2.4 >>>

I used Audacity 1.2.4 forever on some relatively major projects and it worked OK, but I think that's the one with the memory leak. If you use it enough without restarting, sooner or later it will overwhelm the computer and crash.

I'm going to do fluffy stream of consciousness stuff because I don't have a concrete answer. You can't have what you have.

When you do serious audio you should probably really be in the dB scale instead of the percent scale. 2/3 up a linear scale doesn't tell me very much. Go to the little black arrow on the left of the timeline and select "Waveform (dB)". Grab ahold of the bottom of the timeline and pull down so the waves get taller and taller. The dB numbers on the left get more and more accurate when you do that.

6dB down is actually half audio level, but 18 dB down is half volume to your ears. Audio is not straightforward.

Can you give me an idea of how low your show has to be in order to export a show with no distortion?

Another fluffy idea: You might try trashing the Audacity preferences file and put your show specifications in again fresh. I don't actually know how this would help, but If you've been using Audacity for a while and changing things around, you may have hit a condition that is causing damage.

/Users/koz/Library/Preferences/audacity Preferences

Drag that file to the trash and restart Audacity. It will wake up in First Birthday and you will have to set it for stereo again among other things.

Did you start out with a stereo show and now have mono? That will give you a pretty serious level boost. Open your export in QuickTime Player and press Apple-I (info) and see what it says.

Audacity has a nasty habit of trying really hard to play all audio formats whether or not it actually can. QuickTime/Apple-I the audio files before you bring them into Audacity.

Koz

Still having same trouble. From the beginning: I have the MacBook connected to an audio amplifier, which is connected to the turntable. I'm using the microphone socket on the computer, not USB. Audacity receives the signal OK, records it OK, and saves it OK as an .aup file. Then I delete the silences at the beginning and the tail and clean the data with Click Removal and with Noise Removal.

The linear waveform at this point has maxima and minimum confined to +/- 0.7, reading from the waveform axis itself. When I display as dB I see only a wide band with little variation in width, as expected from a logarithmic plot. I don't see why these numbers should be more accurate than those on a linear scale.

Anyway, to get good exportation to .wav, I have to attenuate the audio data with the Effect:Amplify control. Here I must reduce the Amplification (dB) to -10 or more with the slider. If I don't, I get seriously clipped waves when I Export and then Open the saved wav file. The clipping is audible.

The distortion occurs when I don't touch mono/stereo nor the Sample Format.

As I said, the distortion doesn't always happen, but I haven't been able to tie it down.

<<<I don't see why these numbers should be more accurate than those on a linear scale. >>>

Just very different. The bouncing lights audio meters and the tools all work in dB. Having the timeline waveform be in percentages leads to no end of confusion. There doesn't seem to be any correlation--even though there is and everything's doing the same job. It also leads to odd and incorrect ideas, like 0.5 is half volume. It's not. 0.125 is. Video works pretty well by percentages, audio doesn't.

<<<As I said, the distortion doesn't always happen, but I haven't been able to tie it down.>>>

It squeaks on sharp left turns...until I bring it into the shop. Those are the fun ones.

I'm betting you have the wrong Audacity. I run 1.2.4, successfully, and I have a PowerPC machine (G4), not Intel. My Intel machine is running 1.2.5 which is appropriate to that processor. Somebody who we will take out and shoot later today made it so Audacity would seem to work even though it's being installed on the wrong platform. This kills you much later when you try to install plugins and most importantly, the lame MP3 encoder which fails immediately. Frequently months go by between the two events, so nobody ever connects them.

Koz

Nah! I'm using 1.2.5.

Anyway I seem to have figured it out. The clipping in the exported file occurs when I increase the amplification using the slider on the left, attached to the waveform window. It confused me because the waveform doesn't change. I use the slider when I want to hear the sound. It's OK when I return the slider to 0.

Thanks anyway.

PaulK

In order to control the volume for listening you should be using the slider in the contol box at the top (assuming you haven't moved it from it's default location) with the speaker icon (on the left of the mic slider).

As you have discovered (and helpfully posted for others to see) using the gain slider in the track control box acts on your production.

Glad you finally got it sorted.

WC