Talk:Tutorial - Vocal Removal and Isolation

Peter 16Apr12: Initial draft created from a modified version of the Wiki tutorial. Ed 22Apr12: in the intro div we have a "glossary"-flavor link which goes to an http-wiki site; should it not go to our glossary (updating our glossary as needed)?
 * Peter 18Apr12: I have now produced a revised draft of this tutorial. Ed's former editornote in Case-1 made me realize that we don't need to tell users how to do this mandraulically as this technique is superseded by being incorporated into the Vocal Remover plug-in distributed with V2.x, so I have simplified the Case-1 sub-section.  I have also incorprated the two outline recipes for Vocal Isolation that Gale provided from earlier forum postings and turned them into step-by-step guides.  I've tested the first one and it works reasonably well on some material, but I haven't tested the drum removal and I don't have an "Instrumental only" version of any track I have to hand so I can't test the third method.
 * Peter 23Apr12: I moved the Wikipedia link to our Glossary entry - and changed the link here to go to our Glossary#frequency.

To install this plug-in, place "centerpanremover.ny" in the Plug-Ins folder inside the Audacity installation folder. On Windows computers, this is usually under. After restarting Audacity, select the track or audio you wish to remove the center-panned elements from and click Effect > Vocal Remover (for center-panned vocals)... ; it will be found underneath the divider in the Effect Menu. Peter 16Apr12: I don't think the above note is needed. Surely the Vocal Remover effect is automatically installed with v2.x - or am I wrong?

Gale 16Apr12: I have just dump-pasted below raw jottings I have kept on isolation including using Brainworx, Audacity Noise Removal and inversion against a track that has just the instrumentals. Someone should be able to work on this.
 * Gale: Any detailed text for Brainworx for isolation will probably want moving to Wiki too, also noting there that it is for Windows as well as Mac.
 * Ed 17Apr12: did some editing but given the "notes" nature of the text I am going to hold off on any more work as I cannot really see how to "fix" some things like sentence fragments.


 * But if you can remove the vocals, doesn't that imply that you can isolate them as well? Once you have the two tracks, left and right, of just instruments, couldn't you invert them and add them to the original left and right tracks, leaving just the vocals?

No.

(quite tempted to leave it at that) [Center pan isolation can't be done using the inversion, a.k.a. destructive interference, method of center pan removal; another method, spectral subtraction, is required, which is what the Extraboy and Kn0ck0ut plug-ins use]. People are told that they can "remove" center-panned vocals (through inversion of one channel then summing the channels), and then think they can isolate the vocals by subtracting that "non-vocal" version from the original.

Left audio = L Right audio = R Center audio = 2C

Left channel = L+C Right channel = R+C

Remove center audio: (L+C)-(R+C)=L-R (mono)

From the "left channel" and "right channel" (which you start with), there is no simple way to isolate C.

Subtracting the center pan removed mono from the original stereo in an attempt at center pan isolation gives …

Left channel (L+C) and Right channel (R+C) minus center pan removed mono (L-R) => (L+C) + (R+C) - (L- R) => L + C + R + C - L + R {double negative gives "+R"} => 2C + 2R

center isolated audio is “2C“, so “2C+2R” is not center audio.

If you define “Remove center audio“ as : (R+C)-(L+C) =R-L (mono) => 2C + 2L, (which still not “2C” on its own).


 * For popular songs, consider downloading vocals-only tracks from the internet


 * subtracting an instrumental from a song to isolate vocals http://www.youtube.com/watch?v=BKodcXMQHZU


 * Brainworx Solo I use mid-side processors - usually a lead vocal will be panned center, so If I solo just the "mid" channel and mute the "sides" of the sound, a lot of extra stuff disappears (anything that was panned all the way left or right). The sides usually have the lead vocal's reverb on them too, so it helps to pull the FX of the vocal to mute the sides out. I use the brainworx solo plug-in to solo out the mid (VST, au, rtas)

The "heart" of our M/S tools are our unique SOLO BUTTONS that allow you to actually LISTEN to all components of a stereo mix / stereo signal individually.

L(LEFT channel), R(RIGHT channel), M(MONO sum, mid signal) & S(STEREO-Difference, side signal) - and all this phase-corrected (when needed) and mono-ed out on both speakers of your system. This is very helpful when working in M/S modes (because especially listening to only the S-signal of a stereo mix is not so easy to do with modern DAWs) and to check your signals / mixes for errors, noises, clicks, whatever...


 * Re: Extract a vocal from a song AND KEEP THE VOCAL

I discovered a way to get reasonably good isolated vocals. Also it is sometimes possible to isolate vocals by using Audacity's Noise Removal to capture the noise profile of a song that has had vocals removed, then run Noise Removal with that profile on the original mix before vocals were removed. See:

First, using http://wiki.audacityteam.org/index.php?title=Vocal_Removal

remove the vocals from a song. Using the song with vocals removed, sample it as noise profile with the noise removal effect. Apply noise removal to the original audio.

It's still tricky to get rid of anything else in the center (this almost always includes the bass guitar and bass drum), but careful use of EQ can get you a pretty good result.

The following may let you remove drums which are not in center but keep the vocals

If you need to retain center-panned vocals, you can try Noise Removal on the vocal-removed track to isolate the vocals: http://forum.audacityteam.org/viewtopic.php?f=28&t=4956&p=136527#p136527

Then import the original song into Audacity again and try this Nyquist plug-in to move the bass frequencies to center: http://forum.audacityteam.org/download/file.php?id=3065

Then remove the drums from the center by inversion, and finally mix the vocals back in.


 * How about using "isolate" in Noise Removal?


 * isolating the vocals works like removing vocals; in both cases we combine the original waveform with an inverted waveform to “subtract” the part we don’t want. It will leave us, in this case, with the vocal track. In order for this to work, however, you need to have a studio version of the instrumental track. Removing the vocals to get an instrumental track and then trying to isolate the vocals does not work in this case. Don’t be disheartened if you don’t have one ready. Many studios release the instrumental tracks (with and without backup vocals) for use with things like karaoke. There are plenty of places online where you can buy these tracks (like Karaoke-Version.com and some singles and records even have them on the B side) as opposed to the final mono track you get from removing vocals, this method will leave you with a full stereo track. As such, it becomes more important to try and match the quality of both tracks and align them before you isolate the vocals.Open up Audacity and import both the regular and instrumental tracks.

Select the Time Shift tool to roughly align the two properly. Next, zoom in really close and then zoom in more. Take the proper time to align this as closely as you can; pick a peak or trough in the left channel of one track and match it precisely with the left channel of the other track. If the alignment isn’t right the process won’t really work.

Invert the instrumental; Ctrl+A to select all of both tracks. Go to Tracks > Mix and Render.

You’ll get one combined track that should have a more diminished amplitude where the vocals were kept and the instrumentation removed.

=Archiving the former content of Case 1 - just in case we need it=

Case 1: Vocal Removal with vocals in the middle, instruments spread round them
If the vocals are panned in the center of a stereo track (fairly common in "pop" music tracks), the so-called "vocal removal" technique can sometimes be effective by removing what is common to both tracks (i.e. the vocals), leaving behind what is different (i.e. the instrumentals).

To try this technique in Audacity, split the stereo track Ed 17Apr12: maybe needs a better reference on how to split etc.--the links below to the FAQ is broken as it is in the manual now and the linking text does not specify what is being explained: "...of one of them, and play back the result; see some better text of the Audacity FAQ for step-by-step instructions on this technique, or a..." this is the non-http version of the FAQ link: some better text into its left and right channels, make both mono, invert all (or a selected part) of one of them, and play back the result. See this page of the Audacity FAQ for step-by-step instructions on this technique, or a YouTube video tutorial covering the same process. Note this removes everything panned in the center, not just vocals. In pop music this could mean removing bass or rhythm parts. Removal of the vocals can often be incomplete and will leave artifacts behind (especially where there are backing vocals and where reverb (echo) has been applied) as this spreads sound sources, and makes them very hard to extract from each other.

Vocal Remover (for center-panned vocals)
In the current version of Audacity a Nyquist plug-in effect is included to automate the steps involved in Case 1; for fuller details see Vocal Remover. It is accessed from Effect > Vocal Remover (for center-panned vocals).... It includes a Help screen and an option to retain a specified range of frequencies (so removing everything outside that range); there are three choices of removal methods that can be used, for details see here. Although two channels of output are produced the result will be mono because both channels will be identical and panned to center.