Wiring two receivers to one set of speakers?

[Zaurusman]

I have two receivers and one set of speakers. One receiver is an inexpensive late model that is okay for home theater, and another is a late 70's much better receiver that I want to use for audio-only applications. I live in a 1-bedroom apartment and space is such that either they both play in the living room's soundstage through the same speakers or the audio components get stuck in a corner and I invest in a second audio rack for them and good set of headphones. Who knows; maybe I'd get more out of that than playing it through my towers at low volume so as not to disturb my neighbors. Either way, is it possible to wire two receivers into one set of speakers somehow that won't risk damaging the passive receiver when you turn on the other one? If so, how you do that?

[Dusty Chalk]

I wouldn't recommend it.

[Resident Loser]

...wouldn't hardwire them, that's fer sure...there are source switches that can be had, sorta' the reverse of speaker selector switches, but since I have no direct experience with them I hesitate to advise in their use...

jimHJJ(...perhaps someone else has...)

[spasticteapot]

...wouldn't hardwire them, that's fer sure...there are source switches that can be had, sorta' the reverse of speaker selector switches, but since I have no direct experience with them I hesitate to advise in their use...

jimHJJ(...perhaps someone else has...)

Use a speaker selector switch, but backwards - each reciever would use one of the speaker outputs, and the speakers would be connected to the reciever input.

[Blue Meanie]

FWIW, I've done exactly that with a Pioneer SX-780 receiver, a Sansui 9090 receiver, and one pair of Pioneer Hpm-100 speakers. Just wire each receiver to the speakers like you normally would. But make sure the speaker selector switch on whichever receiver isn't currently being used is set to off before powering up the other receiver. As long as you don't forget that very important step, you should have no problems. I had mine hooked up that way for 2 years, with no ill effects.

Jeff

[Dusty Chalk]

Not necessarily -- even when off, the other receiver will still have an apparent input impedance that will screw with the apparent frequency response of the speakers/currently on receiver.

But yeah, if you're going to do it, be very careful to make sure you (a) don't drive the two amplifiers into each other, and (b) don't drive an empty load. Sounds like too many things to worry about to me, hence my original recommendation.

[Blue Meanie]

Not necessarily -- even when off, the other receiver will still have an apparent input impedance that will screw with the apparent frequency response of the speakers/currently on receiver.

But yeah, if you're going to do it, be very careful to make sure you (a) don't drive the two amplifiers into each other, and (b) don't drive an empty load. Sounds like too many things to worry about to me, hence my original recommendation.

But WOULD there be "an apparent input impedance" if the speaker selector on the unpowered receiver were set to OFF? I just assumed that would effectively remove that receiver from the 'circuit'. I am far from an expert on such things,and you may very well be correct.

As for too many things to worry about, turning off one receiver and it's speaker selector before powering up the other receiver isn't exactly rocket science. Admittedly, there are many dullards that would manage to f*ck it up, though.:cornut:

I agree, your solution is probably the best and safest option.:thumbsup:

Jeff

[Zaurusman]

Hmm... Thanks for everyone's input.

If I accidentally power up a receiver such that it tries to drive speakers and its speaker wires are sitting there on the floor, not connected to anything, is that essentially "b?"

[Blue Meanie]

Hmm... Thanks for everyone's input.

If I accidentally power up a receiver such that it tries to drive speakers and its speaker wires are sitting there on the floor, not connected to anything, is that essentially "b?"

Eh???

[Zaurusman]

(b) don't drive an empty load.

[Blue Meanie]

(b) don't drive an empty load.

Thanks. Short attention span. Sorry. Yes, "b". Same as having no speaker wires connected with the speaker selector switch turned on, and the volme knob turned up.
Jeff

[Zaurusman]

With the SX-1280 being reserved for music and used less often therefore, and me having to get up to turn it on anyway (so might as well flip a couple switches), I'm really only risking forgetting to flip 'em back some errant late night when I finally stop the music and putter off to bed, then turning on the Sony from the remote the next morning and pushing air with that one. Eh, I'll chance that happening sometime in the next few years. I'd be pretty angry with myself if it happened and damaged it, but not heartbroken like if it happened to the Pioneer.

Thanks for your help!

[Dusty Chalk]

But WOULD there be "an apparent input impedance" if the speaker selector on the unpowered receiver were set to OFF?Yes, there would still be an apparent impedance presented. It should theoretically be high, but amplifier designers design their amps for being on, they don't usually worry about what it's electrical characteristics are when off. I only mention this because I knew of an otherwise FCC compliant device that changed drastically when turned off, to the point that other people on the video distribution chain were getting sufficiently lousy reception to complain to their cable company. For example.
I just assumed that would effectively remove that receiver from the 'circuit'. I am far from an expert on such things,and you may very well be correct.It's not so much that it may or may not, it's just that I don't know, and I don't like to count on unknowns.
As for too many things to worry about, turning off one receiver and it's speaker selector before powering up the other receiver isn't exactly rocket science. Admittedly, there are many dullards that would manage to f*ck it up, though.:cornut: Hey hey! Who you calling a dullard? Accidents happen...besides some of us have children (not me, but I prefer foolproofish systems).

[basite]

if you just do this: receiver --> speaker--> receiver or variants (whenever both receivers are connected to the speakers at the same time) one of them is going to say boom, and the other one will probably do to later...

if you want to do that, use a speaker selector, or just reconnect the cables every time you switch between home theater and music...

Greetings,
Bert.

[kelsci]

I tried to share my surround speakers between two receivers going backwards into a radio shack speaker selector. My receivers would shut down. I discontinued the connection. I think for some reason, the switching system remained hot. If each receiver had a speaker turnoff switch, that might have worked.

[Resident Loser]

...a speaker selector in reverse probably isn't the way to go...as I recall, some of the have impedance-matching circuitry...probably will cause problems...but, and while it's probably well over $100USD and might be difficult to get (an retain the mfrs. 2yr. warranty) this thing looks like just the ticket:

http://www.russound.com/ab3.htm

You can also download the .pdf manual and check it out...looks pretty safe and fool-proof to me...

jimHJJ(...there may be others, but Russound's been in the multi-room/switching biz way before it became a thing...)

[Rock789]

you will need a 4-pole 2-way knife switch to switch between the receivers... (similar to this 2-pole 2-way)
http://www.herbach.com/Merchant2/graphics/00000001/swh2540.jpg

you could also use relay logic with the trigger outputs of each receiver... require 2 - 12volt dc form c relays w/ bases...

bringing up relays... some amp sections may have a relay on the output which would mean you don't need any of my above mentioned stuff, but... most amps have the relay on the input power, not the output...

[musicman1999]

Better to switch wires on the reciever end,much safer.You only need one set of speaker wires,just switch them from one reciever to the other.

bill

[Resident Loser]

you will need a 4-pole 2-way knife switch to switch between the receivers... (similar to this 2-pole 2-way)
http://www.herbach.com/Merchant2/graphics/00000001/swh2540.jpg

you could also use relay logic with the trigger outputs of each receiver... require 2 - 12volt dc form c relays w/ bases...

bringing up relays... some amp sections may have a relay on the output which would mean you don't need any of my above mentioned stuff, but... most amps have the relay on the input power, not the output...

...also be handy when trying to re-animate the cadaverous body parts you've sewn together...some kites and a Van De Graaf generator and you're all set!!!

jimHJJ(...and maybe someone named Fritz...and No, it wasn't Igor...)

[spasticteapot]

...a speaker selector in reverse probably isn't the way to go...as I recall, some of the have impedance-matching circuitry...probably will cause problems...but, and while it's probably well over $100USD and might be difficult to get (an retain the mfrs. 2yr. warranty) this thing looks like just the ticket:

http://www.russound.com/ab3.htm

You can also download the .pdf manual and check it out...looks pretty safe and fool-proof to me...

jimHJJ(...there may be others, but Russound's been in the multi-room/switching biz way before it became a thing...)

Speaker selectors are just fancy switches.

If you're really worried, just get two DPDT relays and connect 'em to a switch and a 3v wall-wart. Turn on the switch, you connect your "good" reciever; turn it off, and it goes to the default of your HT reciever.

[Resident Loser]

Speaker selectors are just fancy switches.

If you're really worried, just get two DPDT relays and connect 'em to a switch and a 3v wall-wart. Turn on the switch, you connect your "good" reciever; turn it off, and it goes to the default of your HT reciever.

...and all, I'll squelch my immediate tendency to simply reply with "No $h!t, Sherlock"...However some may not be as simplistic as you make them out to be...but then, you must know otherwise to be so authoritative in your response...

There are any number of solutions to the OPs situation, unfortunately nearly all of them require some DIY skills and the tools with which to exhibit them...all the way from simple knife switches to logic-based devices...your electro-magnetic switches (i.e. relays) being one of them, albeit a redundant one. Do we really need a switch to activte yet two other switches? Why not use just a properly configured mechanical switch in the first place? Or at the very least use one multi-contact relay...Then of course, you should really package all the components safely and yada, yada, yada...the device I mentioned is a simple and elegant solution to the OPs switching needs, pratically custom-made to fit them precisely...

So-o-o-o, once you gather up the relay(s), switch, breadboard, power and packaging...and take the time to draw up a proper "schematic" (as simple as the circuit might be), cobble together something that may or may not work properly (you may only get one shot), may or may not look like it was put together by a 4yr.-old (skill and experience-dependent) and may or may not be safe (and certainly not UL-approved)...and again, this is all predicated by the avilability of those proper tools and the skills to use them...he may just be better of finding a proper component that fills the bill...simply plug and play.

jimHJJ(...and with no offense intended to the OP, I have a feeling that may just be what he's looking for...)

[Rock789]

ok,
get a 4-pole form-c relay, 12v coil...
wire the common of the form c to the speakers...
wire the normally closed contacts to the ht receiver...
wire the normally open contacts to the 2ch system...
power the coil with the 12v trigger out from the 2ch system...

it's as simple as you can get... if you want it to be automatic...

[Resident Loser]

ok,
get a 4-pole form-c relay, 12v coil...
wire the common of the form c to the speakers...
wire the normally closed contacts to the ht receiver...
wire the normally open contacts to the 2ch system...
power the coil with the 12v trigger out from the 2ch system...

it's as simple as you can get... if you want it to be automatic...

...Hello, I'd like a Russound AB-3.2

...that will be $XXX including tax

...Thank you...

...Good day sir , do come again...

Simpler...

BTW, do we know if any of the OPs gear has a 12v trigger?

BTW, which one is the sock-puppet?

Of course, one could obviate the need for any such machinations with a single system for both music and video...

jimHJJ(...simplest...)

[Rock789]

indeed

[audio_dude]

I Concur...

[pkats]

Exactly my first thought.