Mixing 2 channel into 1

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How should I mix the 2 channel output of an amp into 1 speaker?

[Todd H.]

writes:

> How should I mix the 2 channel output of an amp into 1 speaker?

You don't.

Doing so would short two amplifier output together and cause them to
"fight" each other and would at best trigger their protection
circuitry, at worst blow em up and start a fire.

A speaker selection switch is the only thing that should ever have two
amplifiers coming in and one speaker going out.

What problem are you attempting to solve with this arrangement? There
must be a better way...


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[[email protected]]

(Todd H.) wrote in message >...
> writes:
> > How should I mix the 2 channel output of an amp into 1 speaker?
>
> You don't.
>
> Doing so would short two amplifier output together and cause them to
> "fight" each other and would at best trigger their protection
> circuitry, at worst blow em up and start a fire.

If the 2 channels don't share a common ground, can I put the 2 channel
output in series, i.e., left + to speaker +, left - to right +, right
- to speaker -?

> What problem are you attempting to solve with this arrangement? There
> must be a better way...

Right now I have 2 surround speakers. But people sitting closer to one
side will only hear that speaker. So I am thinking about replacing the
2 surround with only 1 in the middle.

[Arny Krueger]

> wrote in message
om

> How should I mix the 2 channel output of an amp into 1 speaker?

Run a 8 ohm 20 watt resistor from each amplifier plus terminal to the plus
terminal of the speaker. Run a wire from the minus terminal of one of the
channels of the amplifier to the minus terminal of the speaker. The damping
factor will suck, but it will give you an idea of what it would sound like
if you did things right.

[Robert McLean]

wrote in message >...
> (Todd H.) wrote in message >...
> > writes:
> > > How should I mix the 2 channel output of an amp into 1 speaker?
> >
> > You don't.
> >
> > Doing so would short two amplifier output together and cause them to
> > "fight" each other and would at best trigger their protection
> > circuitry, at worst blow em up and start a fire.
>
> If the 2 channels don't share a common ground, can I put the 2 channel
> output in series, i.e., left + to speaker +, left - to right +, right
> - to speaker -?
>
> > What problem are you attempting to solve with this arrangement? There
> > must be a better way...
>
> Right now I have 2 surround speakers. But people sitting closer to one
> side will only hear that speaker. So I am thinking about replacing the
> 2 surround with only 1 in the middle.

Why not just move both the speakers you have now into the middle, side
by side, with no change to the wiring ?

[Todd H.]

writes:
> (Todd H.) wrote in message >...
> > writes:
> > > How should I mix the 2 channel output of an amp into 1 speaker?
> >
> > You don't.
> >
> > Doing so would short two amplifier output together and cause them to
> > "fight" each other and would at best trigger their protection
> > circuitry, at worst blow em up and start a fire.
>
> If the 2 channels don't share a common ground, can I put the 2 channel
> output in series, i.e., left + to speaker +, left - to right +, right
> - to speaker -?

I have serious reservations about anything that will tie two amp
outputs to a single device other than a switch.

> > What problem are you attempting to solve with this arrangement?
> > There must be a better way...
>
> Right now I have 2 surround speakers. But people sitting closer to one
> side will only hear that speaker. So I am thinking about replacing the
> 2 surround with only 1 in the middle.

I'd fix the spatial problem -- increase the distance from listener to
the surround speaker such that the proximity isn't so radically skewed
by small movements of the listener, and you create a larger area in
which the surround effect with be perceivable rather than only in the
dead center of two surround speakers.

What you're proposing is effectively eliminating the stereo surround
and creating a mono surround channel...the effect of which will be
rather non-ideal. And, as another poster said, if you want to do
that, just put the two surround speakers next to each other. Or,
figure a way to sum the two channels at preamp levels with a mixer or
something and drive the single speaker with a single amplifier
channel. You don't want to attempt to sum signals at speaker levels.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
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[[email protected]]

(Todd H.) wrote in message >...
> writes:
> > (Todd H.) wrote in message >...
> > > writes:
> > > > How should I mix the 2 channel output of an amp into 1 speaker?
> > >
> > > You don't.
> > >
> > > Doing so would short two amplifier output together and cause them to
> > > "fight" each other and would at best trigger their protection
> > > circuitry, at worst blow em up and start a fire.
> >
> > If the 2 channels don't share a common ground, can I put the 2 channel
> > output in series, i.e., left + to speaker +, left - to right +, right
> > - to speaker -?
>
> I have serious reservations about anything that will tie two amp
> outputs to a single device other than a switch.
>
> > > What problem are you attempting to solve with this arrangement?
> > > There must be a better way...
> >
> > Right now I have 2 surround speakers. But people sitting closer to one
> > side will only hear that speaker. So I am thinking about replacing the
> > 2 surround with only 1 in the middle.
>
> I'd fix the spatial problem -- increase the distance from listener to
> the surround speaker such that the proximity isn't so radically skewed
> by small movements of the listener, and you create a larger area in
> which the surround effect with be perceivable rather than only in the
> dead center of two surround speakers.
>
> What you're proposing is effectively eliminating the stereo surround
> and creating a mono surround channel...the effect of which will be
> rather non-ideal. And, as another poster said, if you want to do
> that, just put the two surround speakers next to each other.

When the surround signal is mono (ProLogic), 2 speakers playing the
same sound next to each other will have interference, sounding worse
than 1 speaker.

> figure a way to sum the two channels at preamp levels with a mixer or
> something and drive the single speaker with a single amplifier
> channel.

It's a receiver. It's not easy to mix the surround channels at preamp
level.

[Todd H.]

writes:
>
> When the surround signal is mono (ProLogic), 2 speakers playing the
> same sound next to each other will have interference, sounding worse
> than 1 speaker.

If the surround signal is mono, why are we having this discussion?

The solution is exceedingly easy. Just hook up one surround speaker
plop it in the middle and be done. Leaving the second surround
channel unloaded/unused doesn't hurt anything.

And, there's really no sense trying to sum mono signals from two
different amp channels that are fed the same signal into one speaker.

> > figure a way to sum the two channels at preamp levels with a mixer or
> > something and drive the single speaker with a single amplifier
> > channel.
>
> It's a receiver. It's not easy to mix the surround channels at preamp
> level.

You'll note I didn't say it was an elegant solution. But then again,
your overall solution to a speaker location issue is bound to be
inelegant.

Fix the speaker placement problem if you can (get the surround
speakers farther from your listeners). Failing that, if your surround
signal is mono, just hook one of them up in the middle and be done.


--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

[[email protected]]

(Todd H.) wrote in message >...
> writes:
> > When the surround signal is mono (ProLogic), 2 speakers playing the
> > same sound next to each other will have interference, sounding worse
> > than 1 speaker.
>
> If the surround signal is mono, why are we having this discussion?
>
> The solution is exceedingly easy. Just hook up one surround speaker
> plop it in the middle and be done. Leaving the second surround
> channel unloaded/unused doesn't hurt anything.

But sometimes the source has stereo surrounds. I don't want to change
the wiring everytime.

> > > figure a way to sum the two channels at preamp levels with a mixer or
> > > something and drive the single speaker with a single amplifier
> > > channel.
> >
> > It's a receiver. It's not easy to mix the surround channels at preamp
> > level.
>
> You'll note I didn't say it was an elegant solution. But then again,
> your overall solution to a speaker location issue is bound to be
> inelegant.

My receiver's 2 surround channel amps share a common ground. So right
now I don't have an easy wiring solution.

> Fix the speaker placement problem if you can (get the surround
> speakers farther from your listeners).

I probably have to do this. I'll think about mounting the surrounds
onto the ceiling.

[Todd H.]

writes:

> (Todd H.) wrote in message >...
> > writes:
> > > When the surround signal is mono (ProLogic), 2 speakers playing the
> > > same sound next to each other will have interference, sounding worse
> > > than 1 speaker.
> >
> > If the surround signal is mono, why are we having this discussion?
> >
> > The solution is exceedingly easy. Just hook up one surround speaker
> > plop it in the middle and be done. Leaving the second surround
> > channel unloaded/unused doesn't hurt anything.
>
> But sometimes the source has stereo surrounds. I don't want to change
> the wiring everytime.

Well make up your mind--is it stereo or it mono? You're a very
difficult person to try to help. :-)

> My receiver's 2 surround channel amps share a common ground. So
> right now I don't have an easy wiring solution.

This fact is further exacerbated by your attempting to find a wiring
solution to a non-wiring problem.

> > Fix the speaker placement problem if you can (get the surround
> > speakers farther from your listeners).
>
> I probably have to do this. I'll think about mounting the surrounds
> onto the ceiling.

Please do. Anything else is just a heinous inelegant compromise and
you're running yourself around in circles.

--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."