[Bitrex]

So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

Why is this?

[John Williamson]

On 23/08/2015 15:22, bitrex wrote:
So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

Why is this?

The instrumental recording mentioned in the video has to be from the
same master session as the version with the mixed in vocal, as
otherwise, the two instrumental recordings will not exactly cancel,
especially if they involve anything recorded with a microphone. Of
course, if you have this, then the method is redundant...

A better method would be to use a vocal removal plugin, as is used to
make karaoke backing tracks, then mix the two together with either track
inverted, so cancelling out what was left in the original karaoke version.


--
Tciao for Now!

John.

[Frank Stearns]

bitrex writes:

So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

It's because you need sample accuracy -- time position and amplitude, a perfect
match -- each and every sample, before you can successfully invert and cancel
something. This is highly unlikely, and even somewhat difficult if YOU have the
original tracks in your studio, and not something belonging to someone else you
grabbed off the 'net.

Many little things can kick you way out of the "cancellation envelope" in no time --
different reverb signatures because the vocal was in or out; the varying nature of
MP3 encodes based on input material -- meaning, in this case, the vox in or out will
likely change the way the instrumentals are encoded and thus that portion is not
going to be anywhere near sample accurate and thus, no cancellation.

Frank
Mobile Audio

--

[Bitrex]

On 8/23/2015 12:16 PM, Frank Stearns wrote:
bitrex writes:

So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

It's because you need sample accuracy -- time position and amplitude, a perfect
match -- each and every sample, before you can successfully invert and cancel
something. This is highly unlikely, and even somewhat difficult if YOU have the
original tracks in your studio, and not something belonging to someone else you
grabbed off the 'net.

Many little things can kick you way out of the "cancellation envelope" in no time --
different reverb signatures because the vocal was in or out; the varying nature of
MP3 encodes based on input material -- meaning, in this case, the vox in or out will
likely change the way the instrumentals are encoded and thus that portion is not
going to be anywhere near sample accurate and thus, no cancellation.

Frank
Mobile Audio


Thanks for the reply. I would've thought that even if the two tracks
were not sample accurate there would be enough similarity for some
cancellation to occur - but apparently not in practice.

[geoff]

On 24/08/2015 4:37 a.m., bitrex wrote:



Thanks for the reply. I would've thought that even if the two tracks
were not sample accurate there would be enough similarity for some
cancellation to occur - but apparently not in practice.


Should be some - maybe even enough to recognise lyrics if you
're lucky.

geoff

[Frank Stearns]

bitrex writes:

On 8/23/2015 12:16 PM, Frank Stearns wrote:
bitrex writes:

So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

It's because you need sample accuracy -- time position and amplitude, a perfect
match -- each and every sample, before you can successfully invert and cancel
something. This is highly unlikely, and even somewhat difficult if YOU have the
original tracks in your studio, and not something belonging to someone else you
grabbed off the 'net.

Many little things can kick you way out of the "cancellation envelope" in no time --
different reverb signatures because the vocal was in or out; the varying nature of
MP3 encodes based on input material -- meaning, in this case, the vox in or out will
likely change the way the instrumentals are encoded and thus that portion is not
going to be anywhere near sample accurate and thus, no cancellation.

Frank
Mobile Audio


Thanks for the reply. I would've thought that even if the two tracks
were not sample accurate there would be enough similarity for some
cancellation to occur - but apparently not in practice.

You can check for yourself just how tricky this can be.

Take a track, duplicate it, flip the polarity on the dupe, and mix with the original
at the same level. Should be a perfect cancellation if in a DAW. If on an analog
mixer, you'll quickly discover any differences between your input channels (gain,
distortion, EQ detents, etc).

Now start messing with it... Change the level of one of the tracks; nudge one of
them earlier or later a sample at a time and see how few samples it takes to kill
that perfect cancellation. Adjust the EQ just a bit on one of the tracks; add a
touch of reverb or compression to one but not the other, and so on. It's an eye
(ear) opener.

Cancellation is a handy tool (especially if you want to look for minute differences
between some sort of A and B processes applied to the same track), but am not sure
how effective it can be doing what you want to do. YMMV.

Frank
Mobile Audio
--

[JackA]

On Sunday, August 23, 2015 at 10:22:25 AM UTC-4, bitrex wrote:
So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

Why is this?

I'm not sure what the video is trying to teach!! I mixed an a capella of Magnet And Steel with the hit version, by Walter Egan, Walter seemed to like it!! :-)

Jack

[Trevor]

On 24/08/2015 2:37 AM, bitrex wrote:
On 8/23/2015 12:16 PM, Frank Stearns wrote:
bitrex writes:

So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

It's because you need sample accuracy -- time position and amplitude,
a perfect
match -- each and every sample, before you can successfully invert and
cancel
something. This is highly unlikely, and even somewhat difficult if YOU
have the
original tracks in your studio, and not something belonging to someone
else you
grabbed off the 'net.

Many little things can kick you way out of the "cancellation envelope"
in no time --
different reverb signatures because the vocal was in or out; the
varying nature of
MP3 encodes based on input material -- meaning, in this case, the vox
in or out will
likely change the way the instrumentals are encoded and thus that
portion is not
going to be anywhere near sample accurate and thus, no cancellation.


Thanks for the reply. I would've thought that even if the two tracks
were not sample accurate there would be enough similarity for some
cancellation to occur

So how do you achieve "instrumental and the original precisely aligned"
if the two tracks are not "sample accurate"?
Obviously "precise alignment" is impossible if the tracks are not sample
accurate. But you are right in that *some* cancellation *may* occur, but
it may not actually be what you want to cancel anyway.

Trevor.

[Scott Dorsey]

bitrex wrote:
So, in theory it seems like the method for vocal isolation in the
following YouTube tutorial should work:

https://www.youtube.com/watch?v=_p5QC-4jGWA

Get a high quality instrumental version of the track, align it with the
"vocal" version of the track perfectly, and invert the phase on the
instrumental track and mix to cancel the phases.

In practice, on the tracks that I've tried this with, this method
doesn't work at all. Even with the instrumental and the original
precisely aligned, the rendered track doesn't seem to have the level of
the instruments reduced at all.

Why is this?

This would work only if both the tracks were otherwise completely identical.
Do a little compression or equalization on one or the other before releasing
it (or even worse, lossy digital compression) and it won't null anymore.

There is identical and there is almost-identical and if you're swapping
polarity and summing, almost-identical isn't identical enough.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."