Using Audacity - needing help

Posted: Fri Jul 27, 2007 11:10 am

I'm trying to use Audacity to record from Vinyl.
I want to try to record from the vinyl in as high quality as I can in audacity before I convert it.
I've managed to record from it without a problem. But want to change the options to make sure I am getting the highest quality from the vinyl to start with.
Can anyone help me with what settings I need to change and to what values to acheive this?
Cheers
CC

Posted: Fri Jul 27, 2007 11:38 am

I'm not sure I understand what you are asking here. Audacity takes the digital samples from whatever audio interface you have asked it to use, so the "quality" depends on what happens before the audio gets to Audacity.

If you have a 2-channel, 24-bit 44.1KHz interface, then set Audacity to take its data from there and represent it internally in floating point. If you are intending to write the recorded data to a CD, when you come to export the data as a .wav file, set Audacity to dither at 16 bits, using a triangular dither (or better if your version of Audacity has other options available). Then use Nero or some other simple CD burning program to write the .wav files to a CD.

I assume you have a specific phono pre-amp that has sufficient gain for your pickup cartridge and implements the RIAA equalisation needed.

Posted: Sun Jul 29, 2007 6:55 am

Boswell wrote:

I'm not sure I understand what you are asking here. Audacity takes the digital samples from whatever audio interface you have asked it to use, so the "quality" depends on what happens before the audio gets to Audacity.

If you have a 2-channel, 24-bit 44.1KHz interface, then set Audacity to take its data from there and represent it internally in floating point. If you are intending to write the recorded data to a CD, when you come to export the data as a .wav file, set Audacity to dither at 16 bits, using a triangular dither (or better if your version of Audacity has other options available). Then use Nero or some other simple CD burning program to write the .wav files to a CD.

I assume you have a specific phono pre-amp that has sufficient gain for your pickup cartridge and implements the RIAA equalisation needed.

Thanks for replying Boswell, unfortunately most of that went straight over my head. Problem is I'm a novice to this and I'm trying to understand everything I need to know.

So heres what I'm doing at the moment:
I've got the turntable plugged into a standard amp from a hi-fi.

I've then got the 'tape deck' recording 'out' on the amp plugged into my computer I've got a soundcard with an attachment that I can plug 2 phono plugs into it.

Using Audacity I'm selecting the correc input to record from and recording from the turntable.

That all works fine. But what I want to do is get the 'best' results or highest 'quality' from audacity. So that before I convert it to a CD or MP3 format the digital recording audacity makes is of the highest quality. If that makes sense?
So when recording in Audacity (I'm not talking about exporting it yet) What settings to I need to change so that it records in the highest quality? For example I understand I need a very high sample rate. I want to know what to change to make the orginal recording as good as it can be.

Then I'll worry about exporting it to both a CD and also as a MP3 etc.

I Hope I've explained that well enough and any help would be most appreciated.
Cheers
CC

Posted: Sun Jul 29, 2007 9:11 am

With Audacity open, select Edit>Preferences and then the Quality tab.

What does that read?

Posted: Sun Jul 29, 2007 11:15 am

Space wrote:

With Audacity open, select Edit>Preferences and then the Quality tab.

What does that read?

Currently I've the following settings:
Default Sample Rate - 96000Hz
Default Sample Format - 32-bit float
Real-time sample rate converter - Fast Sinc Interpolation
High-quality sample rate converter - High-quality Sinc Interpolation
Real-time dither - None
High-quality dither - Triangle

I've set them as above. I'm guessing for the sample rate and the float the higher the better. Although I've no idea what that float does.
The others I have left as they were. I've no idea what any of them do.
Any pointers?
Cheers
CC

Posted: Sun Jul 29, 2007 1:29 pm

If you are going to transfer to CD, then use 44.1KHz as the sampling rate for digitising the audio from the vinyl. It's the rate used on CDs, so using anything else will incur a sampling rate conversion (SRC), with attendant loss of quality. Leave the other parameters in the Preferences as they are.

You don't say what your soundcard is, but my guess is that this will be the item that limits the quality of your transfers.

Try a few test transfers and see what results you get.

Posted: Sun Jul 29, 2007 2:23 pm

Boswell wrote:

You don't say what your soundcard is, but my guess is that this will be the item that limits the quality of your transfers.

I have a Creative X-Fi Elite Pro, Although great for games, probably quite bad for sound recording compared to cards designed specifically for the job.

Posted: Sun Jul 29, 2007 2:31 pm

Boswell wrote:

If you are going to transfer to CD, then use 44.1KHz as the sampling rate for digitising the audio from the vinyl. It's the rate used on CDs, so using anything else will incur a sampling rate conversion (SRC), with attendant loss of quality. Leave the other parameters in the Preferences as they are.

Does that mean then if I want to export to both CD and to a high bitrate MP3 files (320kbps), then I need to record each vinyl twice? Once at 44.1KHz to export to CD and one at the Highest sample rate 96KHz to export to MP3 at 320kbps? Or is there a more appropriate sample rate to record in to export to an MP3 format using 320kbps?

Cheers
CC

Posted: Sun Jul 29, 2007 5:05 pm

No, I would just use 44.1KHz. The loss of quality in encoding to MP3 (of any bitrate) is greater than any difference you will hear between 44.1 and 96KHz, given that the source is off vinyl through a standard hi-fi amplifier and a Creative soundcard.

Posted: Sun Jul 29, 2007 7:19 pm

Boswell wrote:

No, I would just use 44.1KHz. The loss of quality in encoding to MP3 (of any bitrate) is greater than any difference you will hear between 44.1 and 96KHz, given that the source is off vinyl through a standard hi-fi amplifier and a Creative soundcard.

I was talking to another person who told me that CD's are done using 16-bit Sample Format. Will using 24 or 32float Bit Sample Format make any difference, or cause me any problems?

Posted: Mon Jul 30, 2007 3:26 am

Read my first reply again. You use the Export As Wav option in Audacity with 16-bit dither set in preferences. This writes a 16-bit .wav file to disk which you then burn to CD.

If you are going to do ANY processing at all in Audacity (even adjusting the amplitude), you need to use as much accuracy of sample representation as possible, and 32-bit float is standard for this. The whole sample conversion process is transparent to you once you have checked that it is set up correctly. Set the internal processing to 32-bit floating point and your incoming 24-bit fixed-point samples will be floated on input, processed in memory as 32-bit floating values and then written to file as 16-bit fixed-point samples when you export as wav.

There's a limit to how much one can say about this - it just works. I would get on and do it now.

Posted: Mon Jul 30, 2007 7:15 pm

You know Boswell is right CChimp!!!

Brien

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