[NTLUG:Discuss] linux and recordings

[Mike Hart]

Coming from analog tape, it's probably a good idea to do a 'noise removal' under the effects menu on audacity.  After you clean the sound, normalizing it will make the sound output better for playing on a CD player. 

Once you have imported your sound through line out/line in. include the following steps:

Noise Removal:

1. select a section of 'silence' that is as long as possible (anything over 3 seconds of hiss is good enough, and I think the effect has a maximum 20 seconds for reference.) 
2. select 'noise removal'
3. select all of the imported audio
4. select noise removal. 

To keep the sound of the tape as uniform as possible, you should do this before you chunk it up.  However, you can run into memory issues if you are working with a long recording, so this might not be possible or time efficient. 

This effect subtracts the noise leaving you with a better sounding recording, unless your recording has a lot of background noise.  It removes hi frequency hiss wonderfully. It  can removes hum also, but if you have midfrequency background noise, you can end up with a final product sounding like you were doing a stealth recording from a closet. 

Normalize:

This step is mostly to bring the audio something more like commercial CD's, since to get the audio in without distortion you probably had to set the inputs very low compared to what you hear on a CD. That is, by normalizing, you won't have to turn the volume 2-3 times higher to hear it on your players than CD's you buy in stores. Normalizing is more of an artform than science.. take the defaults and see what you get. 

Also, for the best sounding Audio CD, save your output file to .wav then open that in a CD burner program (K3B is my toaster of choice.

--- On Mon, 8/22/11, steve at sjbaker.org <steve at sjbaker.org> wrote:

From: steve at sjbaker.org <steve at sjbaker.org>
Subject: Re: [NTLUG:Discuss] linux and recordings
To: "NTLUG Discussion List" <discuss at ntlug.org>
Date: Monday, August 22, 2011, 11:04 PM

> All
> These are amateur home recordings so we are not talking about copyrights
> or licensing issues, OK?
> We are talking about audio only
> What might be the simplest way to made audio CD's from analog tape
> recordings?

First get the data into digital form - so plug your tape deck into the
LINE input on your sound card, fire up Audacity (for example) - press PLAY
on the tape deck and RECORD on Audacity - hit STOP when you're done.  It
may take a couple of tries to get the volume levels adjusted right - but
once you have the right settings, it's easy.

Audacity will let you chop the file up into separate tracks (or whatever)
and tweak volume levels and such - and save them in a variety of formats.

If you are going to make a true audio CD - then you need to save the audio
as a raw ".wav" file or something and burn your disk with software that
knows specifically how to make an audio CD.  I have done this successfully
under Linux - but I don't specifically recall all of the steps involved.

BUT: Many modern CD players will play MP3's from a data CD.  My car's CD
player will do that - and so will the DVD player that's hooked up to my
home theater system.  My car will even play .ogg files - so you can avoid
the ikky legalities of MP3 recording and be TRULY OpenSourced.  If this is
good enough for you than save your audio into MP3/OGG with whatever level
of quality you can live with and you'll get VASTLY more music onto one
disk than the paltry 72 minutes could get with an audio recording - and
the process of burning the CD-ROM is no different than making a regular
CD-ROM.

  -- Steve



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