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jbrant
2009-11-07, 21:22
I have a Squeezebox Classic connected to a stereo amplifier that has no "mono vs. stereo" switch. I am using the system to supply music to two separate areas. I would like each speaker to output MONO sound instead of stereo. Anyone know of a pluggin or other feature that would allow the Classic to output in MONO instead of stereo (same sounds on R and L channels)? Or some other work around (other than using a Y-connector to join the two channels (this is not an ideal solution)? Thanks!

Phil Leigh
2009-11-08, 01:34
What's wrong with a Y-connector ? (The best software solution for this... to use SOX to convert to mono on the fly, assuming you are streaming from a server capable of running SOX)

usch
2009-11-08, 06:18
Anyone know of a pluggin or other feature that would allow the Classic to output in MONO instead of stereo (same sounds on R and L channels)?

Transcoding. With the appropriate parameters LAME can convert a stereo stream to mono, for example. Ask the server experts what to put into the convert.conf file.


What's wrong with a Y-connector ?
You cannot just short-circuit two outputs together. That is likely to damage the output stage.

Phil Leigh
2009-11-08, 06:48
You cannot just short-circuit two outputs together. That is likely to damage the output stage.

Nonsense. We are talking line level here. I've been running stereo inputs into mono amps for 30 years and never had any problem.

usch
2009-11-08, 07:58
It may or may not work, depending on the particular output circuitry. Or it might just degrade the sound quality without killing the outputs.

I like to be on the safe side and have never hardwired line outputs together for 30 years now ;) without at least a pair of decoupling resistors. YMMV, of course.

Phil Leigh
2009-11-08, 08:17
It may or may not work, depending on the particular output circuitry. Or it might just degrade the sound quality without killing the outputs.

I like to be on the safe side and have never hardwired line outputs together for 30 years now ;) without at least a pair of decoupling resistors. YMMV, of course.

You might want to take a look at how mono switches on passive preamps are usually implemented

:-)
... or even on some active ones for that matter...

I've yet to come across any unbalanced (rca/phono) gear that couldn't handle having its inputs summed to mono by a direct l/r connection (which is exactly what the y-connector does).

mlsstl
2009-11-08, 09:00
I'd agree that Y cables to make a mono output are not an issue at the line level stage. I've been an active audio hobbyist for over 40 years (and many years ago also did professional sound work) and never encountered a situation where audio line level voltages could not be combined without issue.

Perhaps the poster who advised against this was thinking of speaker level outputs.

peterw
2009-11-08, 09:09
A Y adapter works fine with the RCA analog outs. See
https://forums.slimdevices.com/showthread.php?t=34613
https://forums.slimdevices.com/showthread.php?t=33899
For a couple years I've used simply Y adapters to feed mono into stereo amps from SB2/SB3 units (though in my case I'm only driving a single speaker with each amp; I only had room for one speaker but already had stereo amps).

Do not use a simple Y adapter with the headphone outs. One of the Logitech engineers said (in reference to the SB Radio) that doing so would cause excess current draw on the headphone amp, sound bad, and might cause damage (the engineer said it probably wouldn't cause damage and was talking about SB Radio, but why risk it?).

jbrant
2009-11-08, 21:30
A Y adapter works fine with the RCA analog outs. See
https://forums.slimdevices.com/showthread.php?t=34613
https://forums.slimdevices.com/showthread.php?t=33899
For a couple years I've used simply Y adapters to feed mono into stereo amps from SB2/SB3 units (though in my case I'm only driving a single speaker with each amp; I only had room for one speaker but already had stereo amps).

Do not use a simple Y adapter with the headphone outs. One of the Logitech engineers said (in reference to the SB Radio) that doing so would cause excess current draw on the headphone amp, sound bad, and might cause damage (the engineer said it probably wouldn't cause damage and was talking about SB Radio, but why risk it?).

Since this is at the line level, I guess I'll try a Y-connector and see how that works. If I don't get any noticeable distortion and it won't cause damage, this would be my easiest option. Thanks!

jbrant
2009-11-13, 21:12
The best software solution for this... to use SOX to convert to mono on the fly, assuming you are streaming from a server capable of running SOX
I like the idea of using SOX, but I'm not sure exactly how to set it up to work with Squeezebox Server and/or MySqueezebox. (Windows Vista platform)