Topic: 4 channel wav file -> Need to remove one channel

[F0CKER]

I recorded Jason Isbell two weeks ago.  I ran B Format to a single 4 channel wav file.  The Z channel (channel 4) had some issues related to the deck where the level spikes to the point of distortion.  I can't decode to stereo without retaining that distortion.  Because the Z channel is height information, I believe I can still decode to stereo and retain a good recording if I can remove the Z channel. 

I've tried loading it into Nuendo as separate mono channels but I can't process using the surround plugin in separate mono files, it only recognizes one channel (W, channel 1).  Is there any way to remove the 4th channel and keep the same file, only as a three track wav, or is there a way to map the 3 mono channels I want to keep so the surround plugin I use to decode will recognize all three channels in the proper sequence, W, X, and Y?

Anyone?  I know the second option, mapping the mono files is possible, I just can't figure it out.

Help!

[live2496]

I think that Richard Dobson's mctools will do this. There is a tool there to separate the interleaved file into separate files.

http://people.bath.ac.uk/masrwd/mctools.html

[F0CKER]

Thanks Gordon, though I'm not sure I'm capable enough with a pc to use cmd lines to get this done.  Let me look mess around with it and see if I can figure it out..

:cheers

[live2496]

Ok. P.M. me if you need some help.

EDIT: I tried this out on an .amb file I had downloaded.

First I put all of the programs into a folder called c:\mctools. Then copied a file test.amb which is the b-format file.
Next, run the command prompt and navigate to the folder.

cd \
cd mctools

Then to extract the first channel...

channelx -oOUTPUT.WAV TEST.AMB 1

This extracts the first channel to a file called OUTPUT_c1.WAV

Then the others...

channelx -oOUTPUT.WAV TEST.AMB 2
channelx -oOUTPUT.WAV TEST.AMB 3
channelx -oOUTPUT.WAV TEST.AMB 4

Files are named OUTPUT_c#.WAV where # is the relative channel # within the file.

To interleave the files again you use the tool interlx.exe
 


 

[Dr.FOB]

Sound Devices has "Wave Agent Beta" that will split poly wav files into mono...
http://www.sounddevices.com/products/waveagent.htm
Haven't used it yet as I record mono and use Soundfields mono>quad to combine.

Also found a Fostex program a while back which I used to split bwf files from the 744T.
http://www.fostexinternational.com/docs/pro_support/pro_bwf_manager.shtml
YMMV

[F0CKER]

Thanks Gordon and Dr. FOB.

I'll do some work tonight and see what I can come up with.

Dr. I tried the quad -> poly program, but since I'm removing the Z signal I think it may not work correctly.  You need four files to do the merge, I only want three.  I tried substitutin the W file, sincve I thought that would be the best as a replacement< but the output is corrupted.  Tried it with others, no success.

I know there's a way to map the W,X, and Y files in Nuendo so the plugin will work, Soundfield send me a note on it before, just can't find it...

Thanks for the feedback.


Imaginary +T's to both of you!

[F0CKER]

Sound Devices has "Wave Agent Beta" that will split poly wav files into mono...
http://www.sounddevices.com/products/waveagent.htm
Haven't used it yet as I record mono and use Soundfields mono>quad to combine.

Also found a Fostex program a while back which I used to split bwf files from the 744T.
http://www.fostexinternational.com/docs/pro_support/pro_bwf_manager.shtml
YMMV

I guess one easy approach might to be to use the Sound Devices tool to split out the mono files, go into the mono Z channel file in Wavelab and remove the section that's distorted, then use the SF mono>quad tool to recombine the original B Format file to it's genuine integrity, minus the distorted section.

That sounds like a good plan of attack for the first try..

If it doesn't work I'll give Gordon's method a try as well, though I suck using command prompts to get anything done..

[live2496]

You might try PM'ing a one of these guys...

Daniel Courville (username=kewl) . He has written some plugins and may have some ideas about what you could do.
Or Hugh Pyle (username=hugh). Has a tetramic and knows a good bit about working with the files. He has written a program but I don't quite recall the details right now.

[F0CKER]

Thanks again Gordon!  I didn't have the time to fuss with it last night, but will try tonight.  I'd imagine there has to be a way to get this done for a person with limited advanced PC skills.  I need a GUI or I'm useless.

[bugg100]

Couldn't you do this in Soundforge 9?  It will open and save multichannel WAV files...

If you don't have SF maybe someone close to you does...

Good luck,
Joe

[F0CKER]

Couldn't you do this in Soundforge 9?  It will open and save multichannel WAV files...

If you don't have SF maybe someone close to you does...

Good luck,
Joe

So I could open the multichannel wav, delete the 4 channel and retain the multichannel wav format?  This sounds ideal.


FWIW, Soundfield also told how to do it in Nuendo.  Here's their response.

Create a Nuendo project.
 
Go to Devices/VST connections and select the Group/FX tab. From here 
create an FX bus in 5.1 format. A new bus called FX 1 will be shown 
in this window. Right-click on where FX 1 is shown and a menu should 
appear that says (amongst other things) 'Add Child bus to FX 1'. 
Click on this option and select 'Add all mono child bus to FX 1'. You 
should now see the individual surround channels listed below FX1. 
I've attached a screen shot to show this.
 
Close the VST connections window and you can now insert the 
Surround Zone into the FX 1 bus. The FX 1 bus output can then be 
routed to a 5.1 output.
 
Create three mono audio tracks from the W, X, and Y wavs.
 
On each of these 3 tracks, go to the output routing and you can now 
choose to route the W track to FX 1 Left channel, the X track to FX 1 
Right and the Y channel to FX 1 Center. This then connects W, X and Y 
to the correct inputs on the SurroundZone, leaving Z unconnected.

[bugg100]

Sounds like pretty good customer support from Soundfield!