Amplifier - wiring help required

[resistorman]

One other possibility is that the speakers are 100v line fed speakers and between the mixer amp and the speakers is a matching transformer to drive the speakers. The Behringer's output doesn't feed into any intermediate device, does it?

You can successfully drive 70V speakers with an amp in bridge mode, I've seen it done. This may be a possibility? Look at the speakers and see if they have any rating on the input plate.

[Mike Stranks]

Bottom line: until we have accurate info about the speakers, we'll surmise and guess...

... and Dave... many UK churches these days are a million miles away from robed vicars and choirs and Miss Simkins playing Hymns Ancient and Modern on the pipe organ... Ask, for instance, Mark One about the audio-visual configuration in his church!

[AlecSp]

Currently the amp/mixer is dropping out occasionally and before we purchase a new one wanted to try this (as we wouldn't want to use bridge mode with any new amp purchased).

Are you sure that it's the mixer amp dropping out? It could be other kit. How frequent are the dropouts? Are they triggered by high signal levels? Can you, for example, pass low level audio consistently without problem, but turn the level up and it will drop out?

I'm not sure on the speaker specs (no labels on the casing).

That's a shame, as basic information like this is obviously helpful for diagnosis. How old are the speakers and the mixer amp?

In the absense of any other info, all this helps give a sense of where root causes could be.

[ef37a]

One other possibility is that the speakers are 100v line fed speakers and between the mixer amp and the speakers is a matching transformer to drive the speakers. The Behringer's output doesn't feed into any intermediate device, does it?

You can successfully drive 70V speakers with an amp in bridge mode, I've seen it done. This may be a possibility? Look at the speakers and see if they have any rating on the input plate.

Yes! Internal 100V transformers in the speakers makes a lot of sense. It's possible the speakers have been there quite some time and there was originally a 100V amplifier in place? Maybe an old 50W valve job!

With the aforementioned test meter, a 100V line traff will read over 16 Ohms I would guess. I have a couple of really old ones kicking about, will refresh the old brain. A clue might be the type of speaker cable. If it looks like 5A lighting flex quite likely to be a legacy 100V feed.

Mike, yes I know churches go in for guitars and drums etc these days but 1000 watts of PA seems slightly OTT and a bit bloody ungodly!

Dave.

[James Perrett]

Mike, yes I know churches go in for guitars and drums etc these days but 1000 watts of PA seems slightly OTT and a bit bloody ungodly!

There's one local modern style church in a local small town where you are looking at far more power than that. I didn't go and check out the amp rack when I was doing sound for a band there but I would expect to find 4-5k or more. Big amps are cheap these days.

[Rob Kirkwood]

"ungodly" made me smile

Quite common for large systems in churches these days. The church we go to now has DB Audiotechnic main PA with couple of Yamaha TF mixers. The church we moved from a year ago has 4 flown clusters of DB Audiotechnic (short line arrays) with an Allen & Heath Dlive s7000 mixing desk, plus 4 projectors - 2 of which are the laser jobbies.

Rob

[panovice]

Nope, the wire from the Speakon connector goes direct to each speaker.

One other possibility is that the speakers are 100v line fed speakers and between the mixer amp and the speakers is a matching transformer to drive the speakers. The Behringer's output doesn't feed into any intermediate device, does it?

[panovice]

When it drops out, it's not that you lose sound completely. It will be working well (i.e. sounding nice and loud and then the sound feels like it's dimmed. This can work in cycles, and sometimes it could be loud or quite for a while.

We've had the amp/mixer for about 5 years. I was looking at a 2 step process.

1 - split the cables and stop using bridged mode. If that fixes the issues, great.
2 - if that does not work, get a new mixer/amp (Yamaha EMX5 seems like a reasonable replacement?)

Thanks again all!

Currently the amp/mixer is dropping out occasionally and before we purchase a new one wanted to try this (as we wouldn't want to use bridge mode with any new amp purchased).

Are you sure that it's the mixer amp dropping out? It could be other kit. How frequent are the dropouts? Are they triggered by high signal levels? Can you, for example, pass low level audio consistently without problem, but turn the level up and it will drop out?

I'm not sure on the speaker specs (no labels on the casing).

That's a shame, as basic information like this is obviously helpful for diagnosis. How old are the speakers and the mixer amp?

In the absense of any other info, all this helps give a sense of where root causes could be.

[ef37a]

"ungodly" made me smile

Quite common for large systems in churches these days. The church we go to now has DB Audiotechnic main PA with couple of Yamaha TF mixers. The church we moved from a year ago has 4 flown clusters of DB Audiotechnic (short line arrays) with an Allen & Heath Dlive s7000 mixing desk, plus 4 projectors - 2 of which are the laser jobbies.

Rob

Nice, and all the while people are relying on food banks and freezing.

I have been a staunch Cathode Follower all my adult life but I do drop supplies into a local church when I can, never been to a service of course but I hope they are not that well equipped!

Sorry for the OTT swerve but there does seem to be something not quite right there?

Dave.

[Rob Kirkwood]

Nice, and all the while people are relying on food banks and freezing.

I have been a staunch Cathode Follower all my adult life but I do drop supplies into a local church when I can, never been to a service of course but I hope they are not that well equipped!

Sorry for the OTT swerve but there does seem to be something not quite right there?

Dave.

Dave I think you're making some very big assumptions here, which I'd be happy to respond to - but like you I don't want to derail this thread any further. Perhaps the Lounge would be a more appropriate place?

Rob

[Hugh Robjohns]

Yes please!

There are already more (technical) assumptions being made in this thread than in the Daily Mail's newsroom. Let's keep Big G out of this.

[ef37a]

Yes please!

There are already more (technical) assumptions being made in this thread than in the Daily Mail's newsroom. Let's keep Big G out of this.

OK HR. Just a bit shocked is all.

Dave.