Driving two sets of stereo speakers with one stereo amp?

[003]

I have an Odyssey Stratos speaker amp and I need to have the ability to drive two sets of stereo speakers with it. There are only hookups for one set of speakers. I know it's possible because I've read about it before, but I am confused, will I need a separate device? If so, what? If I need a separate device, I would like it to be able to:

-Drive both sets of speakers at once (A+B)

-Drive one or the other set of speakers (A or B)*

Can anybody please help me with this?

*When driving one or the other, I would want it to then provide the amp's full power to the speakers, rather than still having it split.

[lini]

For driving one of both speaker sets alone, you'd need an external loudspeaker switching device, e.g. QED SS-21. For driving both sets together, you can just hook 'em up in parallel configuration, provided the amp can handle the combined load - a lot of hifi amps cannot safely drive two 4 Ohm speaker sets together, 'cause they aren't capable of handling the combined load of 2 Ohm (i.e. can't deliver enoguh current). In such a case, if one tries nevertheless and one's lucky, hopefully only the protection circuitry will be triggered - but one can end up with fried power amp sections just as well... In other words: If you want to run two sets of stereo speakers from one stereo amp, you'd better know what you're doing - if in doubt, better play safe, get a switcher unit and only run one speaker set at a time.

Greetings from Munich!

Manfred / lini

[infinitesymphony]

As lini said, it sounds like you want a speaker selector. Just know that with both speakers enabled, the sound quality will probably suffer. I have an integrated amplifier that has much worse sound quality when both a set of speakers and the headphone jack are enabled... I couldn't imagine what it would sound like driving two sets of speakers at once.

[003]

Hmmm... I don't like that monster cable one, it needs you to use their stupid speaker wire connectors, instead of just bare wire, and you have to buy them separately, and they are pricey.

The concept I like though. Do I have any other options that will give the best possible quality when driving both pairs at once? And 100% quality when driving just one of the pairs? I could spend up to $150 including shipping and any other extra expenses.

[infinitesymphony]

Oh, sorry, I didn't realize that the inputs required those tiny connectors... I'm not recommending the Monster, just using it as an example.

100% quality is of course debatable, since the additional connections and the components of the box itself have the potential to degrade the signal quality (though whether or not a particular person would hear the difference is debatable). But, the increased functionality of using the box may outweigh the reduction in sound quality, if there is one. Since these are speaker-level signals, there won't be as much chance for degradation as in an interconnect-splitting device.

I'm sure there are higher-quality boxes with spec'd parts, but the market for these boxes is small... It will take some digging to find a truly audiophile-grade solution, IMO. Otherwise, any box will do.

[lini]

Originally Posted by infinitesymphony

(...) Since these are speaker-level signals, there won't be as much chance for degradation as in an interconnect-splitting device. (...)

Actually, it's rather the other way round - especially over time, as the switch contacts in a speaker switch have to handle a lot more power...

Greetings from Munich!

Manfred / lini

P.S.: 003: In the end, it could be wiser to just get yourself a cheap second power amp on the used market... Or even an integrated amp, so you could independently control the volume for the second speaker set...

[003]

I want to avoid that if at all possible. Are there any high quality of these speaker switchboxes out there? I really would like to get one What about one that has a good electrical design, but uses crappy parts? I could then replace them with high quality ones.

[infinitesymphony]

Originally Posted by lini

Actually, it's rather the other way round - especially over time, as the switch contacts in a speaker switch have to handle a lot more power...

Oh, interesting, thanks for the info. I've heard that signal loss is not such a big deal with speaker cables because the signal is already amplified, so I figured that information also applied to switchboxes.

Originally Posted by 003

I want to avoid that if at all possible. Are there any high quality of these speaker switchboxes out there? I really would like to get one What about one that has a good electrical design, but uses crappy parts? I could then replace them with high quality ones.

Check on Audigon for "switcher" or "selector" every once in a while. There was an Adcom GFS-6 that sold for $85 plus shipping; I've seen that model recommended before. It's also commonly sold on eBay. There's also a three-output version, the GFS-3.

If you can find access to some switchbox schematics and manage to find one with a high-quality implementation but poor quality parts (and a low price), let us all know.

[003]

The GFS-3 looks interesting. Now that I think of the separate amp idea though, it sounds pretty good as well. What about a Sonic Impact Super T-Amp to drive the Canton Patio 160 speakers and the Odyssey Stratos to drive the Polk SDA 1C speakers?

[infinitesymphony]

Originally Posted by 003

What about a Sonic Impact Super T-Amp...

That, or the well-reviewed Trends TA-10.1 would be potentially interesting introductions to class T amplifiers. They're both tiny enough to hide away, and the prospect of getting huge performance for a low price is nice. Plus, with separate amplifiers, you'll be free to move the systems around without worrying about cable runs.

[tourmaline]

Some amps have an A-b switch for 2 pairs of speakers.
it does the same thing as a speaker selector does, 1 pair only, second pair only or both pairs at the same time. As i said, this is amplifier dependant.

[lini]

Originally Posted by tourmaline

Some amps have an A-b switch for 2 pairs of speakers.
it does the same thing as a speaker selector does, 1 pair only, second pair only or both pairs at the same time. As i said, this is amplifier dependant.

Yes, a lot of hifi amps provide switchable outputs for two sets of speakers - usually in parallel configuration. And as you've described, speaker switch boxes provide the same funtionality. However, not every speaker switch box uses parallel hookup - some are also using serial hookup in order to avoid the load problems described above. Some manufacturers offer both, e.g. QED: SS-22 is two-way serial, SS-20 & SS21 are both 2-way parallel (with the SS-21 mainly offering better connectors).

Greetings from Munich!

Manfred / lini