Howto improve the sound quality on instrumentals?

I have the regular version of Audacity as well as the 1.3 Beta version. When I made an instrumental using the split stereo track and clicked mono technique I removed the vocals fine, although the sound quality is a little scratchy or something. Anyone know how to improve this?

With Audacity 1.3.12 you could try the Vocal Remover effect and in the “Removal Choice” setting, select “Remove Frequency Band”. This may help to leave bass and high treble instrument frequencies intact.
You will need to experiment with the frequency band numbers for best results, but try somewhere around “300 3000”.

Thank you! that seemed to produce a better quality instrumental, there’s only a small trace of vocal left. For that should I try amplify and crank it down to the negatives?

Just tweak the frequency band numbers for the best balance of “voice removal : no music damage”.
After that there’s probably not much improvement to be made.

alright, which direction should I tweak the numbers in? at 300 3000 there’s still a small trace of vocal so should I increase or decrease?

The best (maximum) reduction in voice is to set “Removal Choice” to “Simple”.
This will remove everything that is dead centre of the mix (vocal and any instruments that are dead centre in the mix).

The “Remove Frequency Band” option allows you to be more selective about what get removed.
There are virtually no vocal sounds below 100 Hz or above 10000 Hz, so setting the frequency band limits to “100 10000” will still remove about as much vocal as is possible to remove, but it will also still remove quite a lot of the instrumental.

The first number sets the bass (low frequency) limit and the second number sets the treble (high frequency) limit.

“500 2000” will remove less of the instruments (sounds below 500 Hz, or above 2000 Hz will not be removed), but that will also allow some of the vocal to come through.
You need to find the best compromise.