The Ins & Outs of How to Remove Vocal -Sound Forge - PC

Subject:The Ins & Outs of How to Remove Vocal Posted by: Rednroll Date:1/13/2005 12:33:24 AM Ok, over the years I've explained how to remove vocals, and explained WHY in most cases it doesn't work with satisfactory results. I'm going to explain it here in the most detail I possibly can, so down the road if anyone asks this question, please bookmark this post and refer too it. Now there's a few different ways to achieve the same type of things in Sound Forge, so this shouldn't be taken verbatim as the only way to do it, but is the core thought process behind it. HERE'S HOW IT WORKS: In music the vocal in most cases is panned dead center in the mix. The bass guitar and kick drum are also usually panned dead center because these are low frequency instruments and low frequency instruments are referred too as "non-directional". Non-directional means your ears have a hard time being able to tell if the sound is coming from the left or right speaker thus, why they are panned center. Other instrumental parts like guitars, keyboards, drums are not panned dead center. This means that they are louder in level in either the left or the right speaker. When something is panned dead center it means the level in the right channel is exactly the same level as in the left channel. So in removing the vocal what we want to do is subtract what is "common"(ie the same level) in the left channel from the right channel. So the math behind all this is "LEFT-RIGHT"=Center channel removal. So you see if the signal is the same in the left and right channel and we subtract them, then this signal (ie the vocal) will disappear from the mix. How to subtract the LEFT - RIGHT in Sound Forge. 1. Select the Right channel of the mix and only the right channel 2. Goto PROCESS>INVERT FLIP At this point you just inverted the phase of the right channel, so what use to be (+) RIGHT is now (-)RIGHT 3. Goto FILE>PROPERTIES>FORMAT, check "Mono", Click OK. 4. A Dialog box will pop up, and then select "Mix" By selecting "Mix", you chose to ADD the Left and Right channels together therefore you get a final song file of LEFT + (-)RIGHT....or "LEFT - RIGHT" and if your vocal was panned dead center you will see it disappeared.....except for the reverb...more on that later. Also in Sound Forge if you goto PROCESS>CHANNEL CONVERTER and then select the "Vocal-cut" preset, this will do Steps 1-4 for you, then in addition it will take the final single channel mono file from my step 4 and Copy it to both the left and right channels, and then do an INVERT/FLIP as in my Step 3 so the phase on the the Right Channel is 180 degrees out of phase to give it a pseudo stereo effect. Someone from Sony could probably confirm that, but I'm almost possitive that's what they're doing with that preset. SOME PROBLEMS AND HOW TO COMPENSATE: As I previously mentioned instuments like the bass line and the kick drum are also panned dead center in the mix and probably also disappeared along with the vocal and you probably wanted those parts to stay in. Not the end of the world yet, because luckily these bass instruments mainly have energy in the lower frequencies, where the vocal part doesn't. So what this means is that you can do some EQing on one of the channels and make it so these instruments are no longer the same in the left and right channels and therefore won't subtract. Here's a way to do it 5. Goto EDIT> Undo Channel Convert. So this just undid the addition of the channels from the above previous step. 6. Select the Right Channel, and only the right channel again. 7. Goto PROCESS>EQ>Graphic 8. Now click on the line to add a node at around 80Hz 9. Click the line to add a node at 160Hz 10. Drag the Far Left node to -inf. 11. Drag the node you placed at 80Hz to -inf and then drag it to the right so that it is directly below the node at 160Hz. 12. Hit OK What you did here was created a brick-wall Highpass filter at 160Hz. You reduced the level of the bass instruments in their primary frequencies in one channel, therefore the left and right bass parts are no longer the same in the left and right channels. So now when you convert them to mono doing the LEFT - RIGHT process the bass parts will not subtract out, except for their higher frequencies above 160Hz. You can play around with that 160Hz point depending on the vocal part and how much it expands into those lower frequencies. 13. Do steps 3&4 from above and see if you get better results with more bass instruments. VOCAL REMOVER KILLERS: 1.REVERB/FX's Most vocals are blended with REVERB and other FX's. Reverbs are a Stereo FX. That is the original vocal track is a MONO track, but then the engineer will add Reverb to it and the Reverb is a lot of reflections happening at different times, therefore making the ECHO sound of the reverb being different in the RIGHT and LEFT channels. So the reverb part of the vocal is not the same in the left and right channels and therefore will not disappear when you do the LEFT-RIGHT. Therefore the Dry vocal may disappear, but you're left with something sounding like someone singing in the Grand Canyon. 2. DOUBLE TRACKING VOCAL PANNING AND NON DEAD CENTER PANNED VOCALS. Lots of engineers will record 2 vocal tracks and blend them together in the mix stage to give the vocalist a fuller sound. If they're like me, I will Pan one vocal track slightly left of center and the other slightly right of center. While to your ear these may sound identical and the vocal seems to be panned dead center, they are mathematically not identical, therefore the signals are not the same in the Left and Right channels for the vocal part any longer and all bets are off in trying to remove them with the above steps. The same is true if there's only 1 vocal track and in the mix the engineer decided to pan it slightly off of dead center, then your vocal will be reduced but not elliminated. THE IDEAL VOCAL REMOVAL MIX This would be a mix where the vocal was panned dead center with no Stereo FX's like reverb blended with it. All of the other instruments would then need to be panned far right or far left in the mix. If all these conditions are met then you have a pretty good chance of removing the vocal and being left with a good instrumental. Your only problem is that 99.9% of the engineers today don't mix this way. GOOD LUCK!!!!

Ok, over the years I've explained how to remove vocals, and explained WHY in most cases it doesn't work with satisfactory results. I'm going to explain it here in the most detail I possibly can, so down the road if anyone asks this question, please bookmark this post and refer too it.

Now there's a few different ways to achieve the same type of things in Sound Forge, so this shouldn't be taken verbatim as the only way to do it, but is the core thought process behind it.

HERE'S HOW IT WORKS:
In music the vocal in most cases is panned dead center in the mix. The bass guitar and kick drum are also usually panned dead center because these are low frequency instruments and low frequency instruments are referred too as "non-directional". Non-directional means your ears have a hard time being able to tell if the sound is coming from the left or right speaker thus, why they are panned center. Other instrumental parts like guitars, keyboards, drums are not panned dead center. This means that they are louder in level in either the left or the right speaker. When something is panned dead center it means the level in the right channel is exactly the same level as in the left channel. So in removing the vocal what we want to do is subtract what is "common"(ie the same level) in the left channel from the right channel. So the math behind all this is "LEFT-RIGHT"=Center channel removal. So you see if the signal is the same in the left and right channel and we subtract them, then this signal (ie the vocal) will disappear from the mix.

How to subtract the LEFT - RIGHT in Sound Forge.
1. Select the Right channel of the mix and only the right channel
2. Goto PROCESS>INVERT FLIP
At this point you just inverted the phase of the right channel, so what use to be (+) RIGHT is now (-)RIGHT
3. Goto FILE>PROPERTIES>FORMAT, check "Mono", Click OK.
4. A Dialog box will pop up, and then select "Mix"
By selecting "Mix", you chose to ADD the Left and Right channels together therefore you get a final song file of LEFT + (-)RIGHT....or "LEFT - RIGHT" and if your vocal was panned dead center you will see it disappeared.....except for the reverb...more on that later.

Also in Sound Forge if you goto PROCESS>CHANNEL CONVERTER and then select the "Vocal-cut" preset, this will do Steps 1-4 for you, then in addition it will take the final single channel mono file from my step 4 and Copy it to both the left and right channels, and then do an INVERT/FLIP as in my Step 3 so the phase on the the Right Channel is 180 degrees out of phase to give it a pseudo stereo effect. Someone from Sony could probably confirm that, but I'm almost possitive that's what they're doing with that preset.

SOME PROBLEMS AND HOW TO COMPENSATE:
As I previously mentioned instuments like the bass line and the kick drum are also panned dead center in the mix and probably also disappeared along with the vocal and you probably wanted those parts to stay in. Not the end of the world yet, because luckily these bass instruments mainly have energy in the lower frequencies, where the vocal part doesn't. So what this means is that you can do some EQing on one of the channels and make it so these instruments are no longer the same in the left and right channels and therefore won't subtract. Here's a way to do it

5. Goto EDIT> Undo Channel Convert. So this just undid the addition of the channels from the above previous step.
6. Select the Right Channel, and only the right channel again.
7. Goto PROCESS>EQ>Graphic
8. Now click on the line to add a node at around 80Hz
9. Click the line to add a node at 160Hz
10. Drag the Far Left node to -inf.
11. Drag the node you placed at 80Hz to -inf and then drag it to the right so that it is directly below the node at 160Hz.
12. Hit OK
What you did here was created a brick-wall Highpass filter at 160Hz. You reduced the level of the bass instruments in their primary frequencies in one channel, therefore the left and right bass parts are no longer the same in the left and right channels. So now when you convert them to mono doing the LEFT - RIGHT process the bass parts will not subtract out, except for their higher frequencies above 160Hz. You can play around with that 160Hz point depending on the vocal part and how much it expands into those lower frequencies.
13. Do steps 3&4 from above and see if you get better results with more bass instruments.

VOCAL REMOVER KILLERS:
1.REVERB/FX's
Most vocals are blended with REVERB and other FX's. Reverbs are a Stereo FX. That is the original vocal track is a MONO track, but then the engineer will add Reverb to it and the Reverb is a lot of reflections happening at different times, therefore making the ECHO sound of the reverb being different in the RIGHT and LEFT channels. So the reverb part of the vocal is not the same in the left and right channels and therefore will not disappear when you do the LEFT-RIGHT. Therefore the Dry vocal may disappear, but you're left with something sounding like someone singing in the Grand Canyon.

2. DOUBLE TRACKING VOCAL PANNING AND NON DEAD CENTER PANNED VOCALS.
Lots of engineers will record 2 vocal tracks and blend them together in the mix stage to give the vocalist a fuller sound. If they're like me, I will Pan one vocal track slightly left of center and the other slightly right of center. While to your ear these may sound identical and the vocal seems to be panned dead center, they are mathematically not identical, therefore the signals are not the same in the Left and Right channels for the vocal part any longer and all bets are off in trying to remove them with the above steps.

The same is true if there's only 1 vocal track and in the mix the engineer decided to pan it slightly off of dead center, then your vocal will be reduced but not elliminated.

THE IDEAL VOCAL REMOVAL MIX
This would be a mix where the vocal was panned dead center with no Stereo FX's like reverb blended with it. All of the other instruments would then need to be panned far right or far left in the mix. If all these conditions are met then you have a pretty good chance of removing the vocal and being left with a good instrumental. Your only problem is that 99.9% of the engineers today don't mix this way.

GOOD LUCK!!!!