Recording - Distortion/Hiss

[kozikowski]

The Long Version:

The electrical output of a guitar pickup -- certainly the one that I measured -- is just slightly weaker than full line level. You should be able to plug this signal into any Line-In and have very good results. The Line-In and the Instrument-In of many amplifiers are two connections to the same thing.

The signals from a microphone are multiple hundreds of times smaller than that -- particularly if you're trying to record a gentle guitar performance. If you plugged this signal into a Line-In connection, the guitar music and the internal noise of the connection would be similar. By the time you boosted the guitar music high enough to be useful, you would also get very significant hiss, buzz and hash noises.

It is required that an analog microphone be plugged into a microphone amplifier or the Mic-In of a sound card. These connections are specifically engineered to be electrically very quiet and expect very small signals. Because of this extreme sensitivity and noise management, microphone connections are easily overloaded and sometimes damaged by plugging a line/high level signal in by accident. You have to use the right connection for the application.

Many of these decisions can be avoided by using USB microphones. They have their own problems, but selecting the right amplifier isn't one of them. The required amplifiers are built right inside the microphone.

Koz

[kozikowski]

In the event that you have both kinds of guitars, you're stuck with a sound mixer or mixing desk. You may not use two or more connections to a computer at the same time, particularly of different character like that, without very serious and/or expensive considerations.

This kills the podcast people who decide to move up from one microphone to two. That can be a multiple hundred dollar jump.

Koz

[bob_e_s]

Well with my electric guitar plugged into the 'instrument' input, or my mic plugged into the 'mic' input, I get really good results, in terms of quality of sound and useful level.

It's my electro-acoustic that I struggle to get a decent sound with, and it's the songs I've recorded with acoustic guitar that have the most problems with getting the levels right to avoid clipping.

I did read somewhere online that this is a known problem, and your choices are either to record into a mic, as you'll be recording the natural tone of the guitar, not what comes through the piezo pickup inside, or, set up an electric guitar to sound like an acoustic. I will probably go for the latter. Give up on acoustic guitar until I can get a proper producer to work out the recording logistics for me.

I do have a USB mic, but it's a pretty cheap one and can't handle anywhere near the sort of volume I am using.

Cheers,

Rob

[kozikowski]

That puts you in the group having trouble recording rock concerts. They face two different overloads: the moving element inside the microphone stops moving freely and generates distortion, and even if it survives, it can generate such high electrical signals that it overloads the microphone amplifier. The first stage of some microphone amplifiers has no knob. Once it overloads, that's the ball game until you reduce the sound level or put attenuators after the microphone.

Some microphones have a -20dB switch that does this.

Koz

[grayghost9929]

Hello, I've recorded some demos, I suppose, of songs I've written. So I've used synth drums, and then recorded all the other tracks myself (multiple guitar tracks, bass, and vocals). Most playback really clearly (as well as I'd hope) after exporting to MP3 or WAV. Some, particularly tracks with acoustic guitar (although recorded through the pickup, rather than with a mic), have a hiss, or 'roar' in the background once it is exported. It's not the typical distortion I'd expect from clipping through too high a gain, and sometimes one track can seem to have this hiss, while the others are very clear

Don't export using MP3 or WAV. That's the problem. You can't export guitar sounds with those formats, especially "clean" guitars or acoustic. It wobbles and flutters and hisses and does all sorts of weird stuff. It's some kind of glitch in Audacity 1.3. Export your files using WMA Version 2 FFmpeg, 546 kbps. Then, convert from that to MP3 or WAV. That's what I do, and it works great, no more oddities at all.

Open Audacity, and go to:
EDIT > PREFERENCES > LIBRARIES, then click "download" where it says "FFmpeg Import/Export Library". That's the plug-in. Or, you can go to this link and follow the directions: http://manual.audacityteam.org/index.ph ... tallffmpeg

[steve]

Don't export using MP3 or WAV. That's the problem. You can't export guitar sounds with those formats, especially "clean" guitars or acoustic. It wobbles and flutters and hisses and does all sorts of weird stuff. It's some kind of glitch in Audacity 1.3

If you would like to start a new topic we may be able to help resolve that problem. It should not be necessary to go via WMA to get a clean WAV file - in fact, as WMA is a compressed audio format there will certainly be some sound quality loss through doing it that way.

[grayghost9929]

Don't export using MP3 or WAV. That's the problem. You can't export guitar sounds with those formats, especially "clean" guitars or acoustic. It wobbles and flutters and hisses and does all sorts of weird stuff. It's some kind of glitch in Audacity 1.3

If you would like to start a new topic we may be able to help resolve that problem. It should not be necessary to go via WMA to get a clean WAV file - in fact, as WMA is a compressed audio format there will certainly be some sound quality loss through doing it that way.

It is necessary. There is a glitch in the software. No need to make another thread, unless someone else feels like deep-diving into the software and coming up with some sort of fix. I'm not gonna sweat exporting audio to WMA, since Audacity is cheap stuff to begin with and not worth it (that's to me, and excluding for someone that may want to tackle the issue, no offense intended). If this were Sonar or Steinberg or Pro Tools, or some other kind of paid software, then I'd have called them up already and raised the roof a long time ago, demanding either a refund or a fix, but I won't bother for open source (again, no offense to the software authors intended). I take it for what it is, and for that, Audacity works great.

[billw58]

There is a glitch in the software.

If there is a problem with export to WAV introducing distortion then we definitely want to fix it. Can you give us steps to reproduce the problem?

-- Bill