Audacity Forum

I haven't found any answers to this problem on the forum,so here it is:
I have recently been experiencing tracks that are coming out somewhat distorted and at a lower level than they used to be (I have to put the input level almost all the way up to get audible sound). I am using Audacity1.3.7 for Mac and have checked all (I think) variables that might be affecting this- I have changed input and output levels on both IMac and in Audacity; I have switched recording cables(guitar into mic/line input-I have the "line input"option, as opposed to just "Mic in" on my machine); I have checked dither settings and I find this quite strange since I was using this version of Audacity on my Power PC, pretty much without incident until just before I switched over to the IMac. The problem did appear on that machine first, which is why my first thought was a bad cable but that would have been too easy. Would downloading a new version of 1.3.7 help and if so, how would it affect any work saved as "aup" files but not exported?

Koz or Steve, any work-arounds or ideas would greatly appreciated. Thanks.

<<<Koz or Steve, any work-arounds or ideas would greatly appreciated. Thanks.>>>

But if anybody else knows the answer, they should just keep it to themselves.

<<<my first thought was a bad cable but that would have been too easy.>>>

Because you changed the cable and the problem didn't go away?

Mic-In on an iMac just selects the built-in microphone, so that's clearly not what you want. Line-In is the ball game on all modern Macs, and that should work. I have personally, with these hands, recorded one of the editor's Gibson's on my MacBook Pro, so I know the electrical levels are very slightly low, but perfectly workable with an Audacity Effect here and there. (A good strong strum will produce 0.7 v p-p, if anybody asks. That's only about 6dB down from the output of consumer grade sound equipment. Easy fix.)

Apple > System Preferences > Hardware > Sound > Input. Is that volume control all the way up? Do you get good healthy level on the sound meter when you play? It should be over 2/3 up with a strong strum.

How old is the guitar and is the built-in volume control dirty? Run the volume control up and down several times while you're recording and see if it doesn't help. Listen for crackling while you're moving the control. If it does make significant noise, that will need to be repaired or replaced. That will kill you during live performances.

Few people make 1/4" mono plug to 1/8" stereo plug cables. How did you get the guitar into the computer? I made my cable with a soldering iron, electrical tools, and Radio Shack parts.

Clean the connectors. Glass Cleaner, Alcohol, or vodka and paper towels. Scrub both plugs with a wet towel and then dry with another towel. Do not use tissues. They leave a coating. Plug, pull out, and plug again several times. Then clean them again.

Koz

Koz,

The input level on the meters does not look particularly low but the playback waveform is not nearly like previously recorded tracks and there is also the clipping or distortion on the guitar track when I'm listening to it. I have tried switching guitars and cables but nothing seems to change the end result. As for getting into the iMac, I just used a guitar cable which connects to a 1/4"female that has a 1/8 mini plug on the other end(from Radio Shack) and I've tried upgrading to a Monster guitar cable and a gold 1/4" to1/8"cable but I don't notice any change.

I will try the cleaning procedure you outlined but I'm not really expecting this to yield results. Let me know if anything further occurs to you.

Thanks,
CSM

OK, so now it's hard......

I can account for the level, but not the distortion.

...ummmmmm.........

Tell us about your Mac. Size, speeds, drives, OS, Any numbers you can find in About This Mac. Is there any way you can post some of the distorted sound somewhere? If you create a WAV file and zip it (I don't remember how, but I'm pretty sure there's a compression tool somewhere..) and post it here. Don't post MP3. They have their own distortion.

Koz

<<<guitar into mic/line input>>>

Describe the guitar.

Macs don't have Mic/Line inputs. The connector with small circle and two black arrows is high-level only Line-In. You can't plug a microphone directly into a Mac unless it's a USB microphone.

Koz

It's not much of a brain wave, but do you have an iPod or other music player? If you have a stereo 1/8" jumper cable similar to this...

http://www.radioshack.com/product/index ... Id=3433875

you may be able to plug the iPod directly into your Mac and see what half of the system is broken, the Mac or the guitar. If you set the iPod for medium headset or earbud volume, it should make a very nice, if slightly low recording in the Mac.

The distortion bothers me......

Koz

The IMac is a new 20" 2GB Intel unit,so I'd be surprised if that is the problem,although I suppose it is possible. There is a both an input and output on the back of the screen and my speakers are hooked up to the output, so I naturally assumethat the input would take the guitar because my Power PC had done so and there is a selectable input, which is either "Mic" or "audio line in". I think the sound device, listed under about the Mac, says "OSx 879 but I can check further if that helps.

The guitar(s) are ones that I have used to record in Audacity previously (for a Berklee on-line course)and are either a Gibson 175D or a Epiphone Emperor II,usually the former.

I'll see if I can figure out how to post one of the tracks but if anyone knows a surefire method,let me know.

Thanks

The Apple Preference Panel lists a Mic-In in order to select the panel's built-in microphone. On my iMac, it's a little hole just to the left of the camera on the top panel. Obviously, this isn't going to capture the guitar electrical signal.

<<<I'd be surprised if that is the problem>>>

I totally expect this to work. We just need to figure out what happened.

What are your Audacity sound preferences set to? 44100, 16-bit, Stereo. You might also want to mess around inside Go > Utilities > Audio MIDI Setup.

Koz

Do you have QuickTime Pro?
Koz

The prefs were set for 44000 and originally 24 bit, but I changed it to 16bit. I wasn't referring to the built-in mic,although that is an option but rather the input on the lower rear of the IMac screen next to the USB slots which is selectable between mic and audio line-in. I suspect that input is not the problem but somewhere after that stage something has happened or been changed. Is it possible that I unknowingly changed a Pref that would affect this situation? Is there a way to reset the Prefs to "normal" and is this worth a shot? As I mentioned, the program was working fine previously so something has changed but I can't figure out exactly what.

Let me know if "Software playthrough" has any effect on this situation? I have never had it checked and I'm not even sure what it does but "Hardware Playthrough when recording" is selected as a choice in Prefs, which would seem desirable.

I also was reading on the Wiki where an outside audio interface might help. I actually have an M-Audio Fastrak USB interface that I have yet to use and I thought I might try that to see if it has any effect.

Thanks for your feedback.