Speaker Selector and Ohmage

[jagdriver]

I'm looking at a Niles Audio SS-4 speaker selector that can select up to four pairs of speakers. The specs state that it requires an amp that offers a 4-ohm setting, which my Yamaha RXV-2700 does. The speakers sets that will be used are as follows:

(2 individual sets) Bose outdoor speakers - 4 ohm rating
(Single set) McIntosh bookshelf speakers - 8 ohm rating

My question is in relation to the McIntosh speakers, Will I be harming them in any way by hooking them up to a 4-ohm speaker selector, with the amp also set to deliver in 4-ohm mode?

 

[gixxerific]

Correct me if I'm wrong but the Macs will be fine only receiving roughly half the power a 4 ohm version would. Your receiver should be fine. It is stable down to 4 ohms if you were to run less than 4 ohm speakers that could be disastrous but mainly at higher levels of output due to stressed overheating amp.

Dono

 

[Haoleb]

Your speakers will be fine, Also, Dont set your reciever on 4 ohm setting. Leave it on 8 ohms, This is used by manufactuers to sort of cheat their way into making an amp 4 ohm stable by limiting its current. Its meant to keep the amp from overheating driving 4 ohm speakers and so when you turn it on your power is limited and therefore it wont get as hot.

Think of it like taking a huge engine and sticking it in a car that cant handle the power. Instead of letting the engine produce its full power and possibly blow drivetrain up they have limited the power so it wont. Only, You likely wont blow your reciever up. Worst case scenario is that it will overheat and shut itself off until its cooled down.

Look for speaker selectors that are impedance matching which means you can hook lots of speakers up and still be ok with not having too low of an impedance.

 

[skers_54]

I'm not an expert, but I think that it recommends a 4-Ohm stable amp in order to protect the amp when running several sets at once. The switch doesn't have an impedence; it just allows you to run multiple speakers from the same output channel in parallel. From my math, running all 3 pairs of speakers together would show a 1.6 ohm nominal load to the amp, which is well beyond the capabilities of many receivers. Even running a pair of the Bose with the Macs would have an equivalent impedance of 2.6 ohms. Your Yamaha has a robust power supply, but I would be hesitant to run all 3 (or even 2) sets of your speakers simultaneously. Hopefully someone with more experience with distributed audio can chime in and clarify (since I probably have something wrong).

 

[jagdriver]

I should have stated that, due to room configuration and other factors, only one speaker set will ever be used at one time, so the nominal resistance will always remain 4 ohms.

 

[Haoleb]

I should have stated that, due to room configuration and other factors, only one speaker set will ever be used at one time, so the nominal resistance will always remain 4 ohms.

Every speaker selector box i have looked at has at least some sort of amplifier protection incase you turned every single one of them on at the same time, But if your only going to use one pair at a time then the Niles one your looking at will work just fine, and your amp will power them no sweat.