How connect 1 pair speaker two 2 amplifiers

[Guest]

Hello,i have one Yamaha 470 and Marantz SR7500 and 1 pair of JBL ES90. Is it possibly safe to connect both amps to the speaker? Of course, only 1 amp should be turned on at a time. Your input is highly appreciated. -ATM

 

[soundguruman]

No, you can't do it that way. You would need a disconnect switch to disable the output connections one amp at a time. You risk destroying both amplifiers.
You can't use one amp with the other connected, even if it's off.

 

[astrallite]

The Yamaha 470 is a piece of crap anyway.

 

[Guest]

To slightly clarify soundguruman -- the problem is that unless the (theoretical) switch can isolate the amp which is not being used the amp that is being used will be looking into its output section.

Most existing switches are designed to use two pairs of speakers with one amp.

And I'm with astrallite on that generation of Yamahas -- I have a 350 receiver now retired with failing input switchery, doubtless from cheap components.

 

[buwish]

Best answer selected by buwish.

 

[mehrdadx 46]

Hi
Can i use two speaker in one terminal out of amp?

I connected two 4 ohm speaker in series to A speaker out) , & connect 8 ohm speaker series with 7.5 ohm woofer added

to : (B speaker out).

usually i use A speaker out only & somtimes A+B !

In (A out) i have 2ohm total & in (A+B) i have 5.8 ohm !!

I find that it is dangerous but i used them in this situation about two years !!

is it dangerous for Amp?

if i add some speaker & calculate them ( in Parallel & series form ) & the total impedance reach the 8 ohm or 12 ,
is it safe?

A/
speaker 1 = 4ohm 200watt
speaker 2 = 4ohm 75 watt
B/
speaker 3 = 8ohm 100 watt
woofer = 7.5 ohm 30watt

speaker out of amp : A or B = 4 -16 ohm , A+B = 6 -16 ohm
but can give 290 watt to 2ohm