Hi

In our main hall we have about 20 100v speakers all powered by a 100v amp via a mixer.

We are in the process of having an acoustic sliding partition installed which will split the hall in to 2 sections and this will allow us to hold 2 activities at the same times.

What we now want to do is for the pa system to remain as it is in section A of the hall but in section B we want the ability to:-

a) play the sound from section A (which already happens as it is one system)
b) install a mic point in section B and have the ability to play the sound from this mic only on the speakers in section B

Basically we want the ability to have 2 different activities going on using mics in the 2 sections.

I hope that makes sense!

What do we need to buy to allow is to do this?

Thanks

I think the easiest thing for you is to buy a zoned mixer amplifier, not very cheap but simple. the other option is to buy a second amp and assign it to a separate group on the mixer,

You will also have to separate the speaker wiring physically, as it is likely to be one run with many cabs on it. If you have to get someone in, with access equipment, this will cost more than the new amplifier that you will need.

If I were doing it, I think I would have both amps in the same place, and a simple switch to select either MIC A to A & B, or MIC A to A and MIC B to B.

If the mixer is stereo, have left as zone A and right as zone B.

Will still need another amp more than likely, and as stated before that will be cheap compared to the work if you need access equipment.

If zone A and B are already on separate cable runs as you seem to be implying, then life becomes much easier. You are right that if A is already on one channel and B on the other, provided you have no crosstalk, you can put different signals down the L & R channels on the stereo amp with A connected to L and B to R for example. You mention a mixer. If you already have one, then you have two or three choices. Use the existing one with a long balanced mic lead to the new position, and feed that to channel B when you need it, else feed the existing signal to both channels. The difficulty here is that the mic control is then in the other room. Alternatively, buy a cheap mic input pre-amp and run a line level signal back to the main mixer. Or buy a radio mic for use in the B section.

One thing to watch out for on the mixer is the PAN controls. If you are not careful, you could end up feeding both mixer outputs with the same audio stream unless you have the PAN controls hard left or right.

Robin

Blimey there's some wild guesswork going on here.

Can I suggest that before anyone else posts they go back and read the original post. It's highly unlikely that the OP has a stereo amp, I can count the number of 100v stereo amps I've seen in 30 odd years on one hand. Mixer? Where did that come from?


To IA76....what amplifier is currently installed? If you don't recognise it then post a photo. It'll help to give you the right answer.

Also to IA76...will you ever want to run system A at the same time as system B with different signals running in each one?

Whoops. My error. I thought the response from a later poster was the OP coming back!

Well cautioned Brian.

Funny that. I wrote exactly the same thing, then went back and found that the OP says he has a mixer in his first line. I deleted my own post.

I thought I'd read it somewhere.

Incidentally Brian, seven of the eight 100v line amps in my place of work are stereo (or twin channel if you prefer). In my 40+ years the majority of amps driving older systems (Installed prior to about 1990) were single channel, but many later ones are based on standard amps and hence are delivered as dual channel rack mount units.

Hi All

Sorry for the delay in replying.

Just to confirm it is a mono single channel output amplifier and we do have a Peavey XRD 680 mixer as well (it's a powered mixer but we just use it as a mixer).

"Also to IA76...will you ever want to run system A at the same time as system B with different signals running in each one?"

Brian, yes that is exactly what we want to have the ability to do.

So, your 'to-do' list is...

1) Separate the speaker wiring into the two areas
2) Buy another 100v amp

...and then decide how to wire it up.

You could feed each area from it's own amp and then feed the amps thus...

Amp A - fed with Mic A

Amp B - fed with Mic A and Mic B

with each amp feeding its own area

...or...

Amp A - fed with Mic A

Amp B - fed with Mic B

with Amp A feeding area A and with area B being fed from Amp A OR Amp B depending on a changeover switch. I'd go with this one.

I now know exactly what we need to do.

Can you give me a link to the kind of changeover switch we should be using. If possible we want one that will work with 3 mics & 3 amps and allow any mic to be sent to any amp (this would ocver any future plans we have)

What I would normally recommend is something like a Biamp Nexia processor to handle room combining. If you buy the Biamp Logic Box you can use a contact closure on the partition to reconfigure the system automatically when the partition opens or closes.

Using a product like this will also allow you to have simple wall mounted interfaces for source selection, volume control and recalling of presets.

This isn't the cheap way of doing the job but is the most elegant way and leaves plenty of scope for adding to or changing the system in future.

Stu

We use an Allen&Heath idr8 for main FOH to allow us to do this - possibly slight overkill for this application with 10 inputs and 10 outputs though! Having said that, its got all the processing too (delays etc) should you wish it, and can also be hooked into a fire alarm relay to kill the output.

For our stage monitors, we use use Cloud CX163 (purely to cut off the sound in case of fire), this is a two stereo channel mixer to two stereo outputs - as the others say, you can send either of the mixes to either output, and has an extra input for a mic (not quite figured the purpose of that). I would suggest for redunancy maybe the Cloud CX263 for you - this gives you three stereo channels input and 3 outputs - just gives you extra flexibility should you need it. (http://www.cloud.co.uk/zone-mixers-22.asp) I can't fault these units, we've got two spares as back up, and have never had to use them)

I don't remember what we purchased them for, but they're not unreasonable and fairly popular for installs. All of ours were purchased through VME UK and I would imagine they still sell them.

We certainly do! Have a look at Skytronic / Adastra for cheap 100v amps.