multiple speakers on single output possible ?

[hypernova]

im kinda beginner in this so i need some advice.
i have a onkyo tx-ds 939 amp with 5 speakers and 2 subwoofers connected.
my front speakers are 8 ohm and i wanted to connect some other 4-8 ohm speakers at the same audio output. my amp tells me not to connect speakers with lower than 6 ohm.
i know i wont get more power or better sound with that.the reason why i wanna do that is cause i just want more sound sources. thats why i already connected 2 subwoofers (yamaha yst-sw150 + yst-sw300).
if thats not possible or a good choice i have another onkyo amp (tx-ds 656) . is it possible to connect both amps ?
but only one amp needs to be connected to digital sources ?

 

[MDS]

If you connect two additional speakers to the L/R channels and wire them as you propose (wires twisted together and attached to the same binding post on the receiver) then the speakers will be in parallel and the impedance will drop - way below the stated 6 Ohm recommendation.

If the current fronts are 8 Ohm and you connect two more, the impedance will be 1 / (1/8 + 1/8) = 4 Ohms for each channel. Add 4 Ohm speakers and the impedance will be ~2.7 and the amp may shut down.

You could wire the additional speakers in series with each other if you really want more speakers. You could also get an impedance matching speaker selector that allows simultaneous play of multiple sets of speakers. Problem is it will be very tough to find one that maintains 6-8 Ohms (most are 4Ohm).

 

[hypernova]

thx for ur reply first
so u mean i connect the 2nd speaker (4-8 ohm) to the amp same way as the first (8 ohm) is ?
or do i connect the 2nd speaker at the back connections of my 1st speaker which is connected to the amp ?
u said something about twisted wires - why should i twist the wires and connect them at the same output ?
and will there be any quality losses when i connect them in series ?

 

[annunaki]

What he is saying, is that it really should not be attempted. You risk causing damage to the receiver. Why do you need so many speakers hooked up? 5 or 7 is not enough? How large is your room? If one would do this, (hook up additional speakers) it is recommended that an impedance matching speaker selector be used.

By the way, running speakers in series doubles resistance making the load safe on the typical receiver, but also halves the power. Say you had two 8 ohm speakers and your amplifier does 100 watts into 8 ohms. If you run them in series, the resistance would now be 16 ohms, but the amplifier will only output 50 watts for both speakers to use. There would really be no advantage to doing this, as the overall volume would stay the same. (doubling surface area = +3db; halving of power = -3db)

 

[hypernova]

ok i think i wont connect anymore speakers now that u all say its not really needed. but now i have some other problem
But gonna start new thread about that !