Walked into this, this afternoon

BillESC

Well-Known Member
A local country club asked me to look at their sound system today.

I found four wireless mics in the 600 MHz range, a mixer, a CD player, tape deck and one EV PA4150L amplifier. Behind the rack I took a picture of the speaker home runs. I haven't pulled the amp out of the rack to see the back but I'm sure I'm going to like what I see.

The picture will show 12 speaker line combined to six.

proxy.php
 
A local country club asked me to look at their sound system today.

I found four wireless mics in the 600 MHz range, a mixer, a CD player, tape deck and one EV PA4150L amplifier. Behind the rack I took a picture of the speaker home runs. I haven't pulled the amp out of the rack to see the back but I'm sure I'm going to like what I see.

The picture will show 12 speaker line combined to six.

proxy.php
@BillESC What did you do to annoy God and do you feel you're about to be smitten by her or turned into a pillar of salt??
Toodleoo!
Ron Hebbard
 
Last edited:
Looks like a fun project. You will rack in that golfer politician money. Milk the crap out of this and eat well.

Take lots of pictures of this progress.
 
Nice to see there's something. I've been in country clubs with in ceiling speakers in 40 foot ceilings. Maintainance finally got up there to look at them when the audio was so incredibly bad to find out half the speaker covers didn't even have any speakers. They stupidly installed 2 Eons to replace.
 
OK, I'm going to try to learn something here, so bear with me.

Ignoring the CAT5, I see 6 feeds coming in from the bottom of the barrier strip, assumed to come from the amp, each leading to a pair of feeds to presumed 8-ohm speakers out the top. So each input feeds two outputs, for an effective load of 4 ohms per input. BUT the PA4150L is a 4-channel amp, so where do the extra 2 feeds come from? Let's see a picture of those 6 feeds at the amp, if in fact they all originate there. That's where the smoking gun will be.

Suppose the following connection of the 6 4-ohm feeds, I'll call them A-F, to the 4 output channels of the amp, 1-4.
  • Channel 1 to A - 4 ohms, OK
  • Channel 2 to B in series with C (8 ohms), in parallel with D in series with E (also 8 ohms), net 4 ohms, OK
  • Channel 3 to F - 4 ohms, OK
  • Channel 4 available for expansion.
Other creative schemes are possible and the PA4150L can operate in bridged mode, allowing for even more permutations. Which is why I generally stick to lighting...

I'm curious as to WHY you were asked to look at the sound system. If it's because 4 of the speakers are silent, perhaps they aren't actually connected at the amp. If it's because of volume variations or distortion at the speakers, perhaps something like the Channel 2 scheme above.
 
Well I once worked in Rye, NY at the high school. TTI did the audio console, yes you read that correctly.

There were 10 faders on the custom made console, 4 fed a quad pan unit, the console then fed a single Crown stereo amp, which fed one single Voice of the Theater center hung speaker, whose low end speaker had been spray painted white. 10-4-2-1 system ?.

I was only visiting thank God.
 
@Chris Beall,

It's possible that they're running some channels at 2Ω with 4 speakers on a channel. That amp is not designed for that and they specifically discourage it on their cut sheet. Regardless, it probably still makes sound come out of the speakers without faulting the amp or blowing anything up.

The dirty secret is that while these days there are a lot of amps that are advertised as being able to drive 2Ω loads, you should avoid this unless absolutely necessary. It will impact how it sounds, adds distortion, and puts undue stress on the electronics of the amplifier. The reason this shows up as a feature on many cut sheets is to help sell product for people who want to known they can string (4) 8Ω speakers onto a channel if they ever need to, and a lot of people just don't pay attention to how different it actually sounds.
 

Users who are viewing this thread

Back