H Gavin
I dunno if you use LAME but it can convert WAV to MP3
MP3 to MP3
and there are options for stereo or mono or Joint outputs too.
I think thats what you want.

LAME version 3.96.1 (http://lame.sourceforge.net/)

usage: lame [options] <infile> [outfile]

<infile> and/or <outfile> can be "-", which means stdin/stdout.

RECOMMENDED:
lame -h input.wav output.mp3

OPTIONS:
-b bitrate set the bitrate, default 128 kbps
-f fast mode (lower quality)
-h higher quality, but a little slower. Recommended.
-m mode (s)tereo, (j)oint, (m)ono
default is (j) or (s) depending on bitrate
-V n quality setting for VBR. default n=4

--preset type type must be "medium", "standard", "extreme", "insane",
or a value for an average desired bitrate and depending
on the value specified, appropriate quality settings
will
be used.
"--preset help" gives more info on these

--longhelp full list of options


Gavin Stephens wrote:
>
> Hi guys,
>
> Does anyone know of a programme that will allow me to convert a mono
> wave to stereo wave file from the command line?
>
> This may interest the od LPFM station that uses the Newstalk ZB
> affliliate units FTP service.
>
> I've been tidying up some scripts/batch files I've been slowly
> perfecting over the past 4 years after creating some for use with the
> Newstalk ZB affiliates FTP service. Orginally I created them to
> download the news, decode it, normalise it in to a system using
> everything at 98% peak audio levels, then tag the files and import
> them in to Simian automation software unattendent.
>
> Anyway, the one thing I'd like to see done is for the service to
> deliver news in an mp3 VBR format but in MONO for distribution and
> bandwidth savings. This reduces the file size from the current ACM mp2
> @256kbps stereo files of around 4.6MB for the news alone, to around
> 1.4MB. I was told the other day TRN's latest IT cheif is interested
> again in providing and MP3 option (had one of those emails about 4
> years ago saying they were looking in to it but then Ed Taylor left
> and I left the station I was with at the time), but I'm coming up with
> a means to do it easier for them again.






















Cheers
Geoff Barkman
ZL4TUX