Loudspeakers Ohms Question

[garyvp]

After some very clever and tedious wiring of speakers of various impedance s, then going the 70v tranny route, and even with proper good quality individual speaker volume controller at each speaker, we got really lousy results and blew a few cheap sold state amps, so I installed an inexpensive impedance matching 6 speaker distribution system - we have six green room speakers throughout the building. This allows simple connections and wiring, offers great control and protects the amp. I should have don this straight away...wasted a lot of time.

 

[microstar]

After some very clever and tedious wiring of speakers of various impedance s, then going the 70v tranny route, and even with proper good quality individual speaker volume controller at each speaker, we got really lousy results and blew a few cheap sold state amps, so I installed an inexpensive impedance matching 6 speaker distribution system - we have six green room speakers throughout the building. This allows simple connections and wiring, offers great control and protects the amp. I should have don this straight away...wasted a lot of time.

No offense, but if it took "clever and tedious wiring" to install a 70v system and blew up amps in the process, I would think something was not done correctly and the lousy results would be the outcome. The system is meant to simplify the process, not make it more complicated.

 

[garyvp]

No offense taken. It was not done correctly. This is a community theater and while are dimmers and sound systems are properly outfitted and matched, the house mike is cobbled together from the parts department. What led us to this was first someone just added several speakers to the current house mike circuit in parallel and there went the first cheap PA amp. We had four different kinds of speakers with different impedances. I researched the net (pre Control Booth) and attempted to wire it correctly but was warned that old and varying wire size and lengths and unknown impedance would make it difficult - worked great with three matched ones - but soon the second amp died (they were not expensive). There was a requirement that each speaker had it own volume control (different rooms.....this did not work well with the 70 volt system with transformers. Power was was an issue as well. So I went to J&R electronics for advice, we got a better amp, ran new wires where we could and with the impedance matching distribution it has all worked fine with the various legacy speakers. . Not a great expense either. I am good with electrical but this was an education.

 

[Les]

Sounds like quite the rabbit trail. Luckily the system in this thread is for infrequent paging only, so quality isn't terribly scrutinized (though it's actually not bad).

Thanks for the replies regarding powering the amp 24/7. I had a feeling that would be the best case. I don't have a problem with putting it on a timer except that I felt like it could possibly do more harm than good. If this amp dies while I'm still around, I'll probably replace it with something from Bogen or similar.