maximum # of speakers

[marty9]

Hi Everyone,

I'm a volunteer at a campground and we would like to add speakers to our current system. At the moment we have 2 pairs of speakers in a dining hall up at the camp. We have a left and right at the front of the hall and a left and right at the back of the hall. This is just for music and not used for any surround sound. Both pairs are wired into the A channell on the receiver.

We have recently had 2 pairs of outdoor speakers donated to the camp and we would like to have them mounted on 2 sides of the dining hall.

I was planning on using an external speaker selector to control the 4 different pairs of speakers.

My question is, will having 4 pairs of speakers connected to the A channell of a receiver cause problems for the receiver? These are all small bookshelf speakers. The indoor speakers are 8 ohms, and the new outdoor speakers are 6 ohms. There will be many times that all 4 pairs will be used at the same time. The receiver has A and B Speaker selection, should I wire 2 pairs on each instead?

Do I need to buy a speaker selector that has overload protection?

Thanks for all your help!

 

[skumar]

More details on the Amp will help the experts here (self not included) to help you.

If there is a provision on your Amp to play both A and B speakers simultaneously, you should connect a pair to B definitely.

 

[marty9]

Thanks for your replies so far.

The receiver is a surround receiver (Sony STR-DE945). I believe it's either rated at 100 watt or 120 watt output. The speakers aren't being set up to rock the joint or hold dance parties ... mainly for background listening.

I'm not trying for any sort of surround effect or music hall sound field and the receiver does not have a 5 channel stereo option like many others do.

The extra speakers are wanted so that music doesn't need to be played too loudly to be heard in different areas.

Inside the dining hall we currrently have 2 pairs of bookshelf speakers. One pair in the front (L and R) and another pair in the back (L and R). We would like to add an outdoor pair (L and R) on the outside of the dining hall where we have a large deck, and another outdoor pair on another side of the dining hall where we have a few picnic tables and horseshoe pits etc.

I'm fairly new to this and I'm not quite sure I understand parrallel and series wiring.

I was wondering if one pair of Left and Right speaker wires went from the receiver "A speakers pins" to an external speaker selector and from there the 4 sets of L and R wires ran to the 4 pairs of speakes both inside and outside the dining hall. This would give the choice of which speakers we wanted to have on at any given time.

Would the above set up cause problems for the receiver? Even if I buy the more expensive speaker selector that has an overload pretection built in? Is overload protection the same as low impediance protection?

Thanks again for your help!

 

[venkatcr]

I was wondering if one pair of Left and Right speaker wires went from the receiver "A speakers pins" to an external speaker selector and from there the 4 sets of L and R wires ran to the 4 pairs of speakes both inside and outside the dining hall. This would give the choice of which speakers we wanted to have on at any given time.

Would the above set up cause problems for the receiver? Even if I buy the more expensive speaker selector that has an overload pretection built in? Is overload protection the same as low impediance protection?

The speaker selector is simply a switch which will make the amp think it is connected to one pair of speakers at any time. This is a very safe way and will not harm either the speakers nor the amp/receiver. If you have noticed such a selector is used in many demo rooms to demonstrate a large set of speaker pairs with the same amplifier.

Overload protection is used to cut off power in excess of what the speaker is rated to carry. The protection could also work in reverse where it will stop the amp from clipping. This is different from impedance which Cranky has already explained.

Cheers

 

[marty9]

I've heard that attaching too many pairs of speakers to the same channell of a receiver can burn out the receiver ... do better quality speaker selectors protect from receiver from this even if all 4 pairs os speakers are being used?

The receiver does have a circuit protection built in.

I'm a fairly novice audio person here, I can't do or understand much more than hooking your basic components and a surround sound system. Multiple speakers, impediance, clipping, parrallel and series don't really mean anything to me.

Thanks again for any info or advice!

 

[venkatcr]

I've heard that attaching too many pairs of speakers to the same channell of a receiver can burn out the receiver ... do better quality speaker selectors protect from receiver from this even if all 4 pairs os speakers are being used?

As I have already explained, when you connect a speaker selector switch, the amp/receiver will see only one pair of speakers at any time. All the other speakers will be disconnected from the amp/receiver. You can connect as many speakers to the other end of the switch as there are connection points available. Even if you connect 4 pairs of speakers, at any time, the amp/receiver will drive just ONE pair of speakers depending upon the switch that you press on the selector box. There is no question of the amp burning as long as you put the speaker selector between the amp/receiver and the speakers. The speaker selector, as I said, is just a simple switch. There is not much technology in it. Buy a speaker selector from a reputable company and you are safe.

Cheers

 

[marty9]

But some speaker selectors let you have all 4 pairs on at the same time, would that not cause problems for the receiver?

 

[Kamal]

If you connect the selector to one speaker out ( A or B ) & play all the four pairs, it could cause probs to the receiver.
Here's the link to the manual for you receiver-
http://www.docs.sony.com/release/STRDE945.pdf
As you will observe from the front panel diagram of the Sony receiver on page 27, on the right hand side there is a rotary switch allowing you to select speaker out as A, or B or A+B.
So, all you need to do is to connect the two pairs inside the hall in series & then connect the wire to the front A outputs(one pair can be connected to the left ouput of A & the other to the right out of A).
Similarly, connect the two pairs ouside the hall in series to the left & right channelof speaker out B .
Make sure the speaker impedance switch ,located just below the subwoofer out-see page 16 of the manual, is set to 8 ohms, & set output to mono.
With this set of connections you would'nt need a selector switch, just select A or B or A+B as required with the switch on the front panel.
With the speakers set up in series the impedance would get added up but that should present no problems to the receiver since the setup would be used to primarily to provide low /med level background music, not to blow the party.