Underpowered power amp question

[cnnrward]

So I go to High School and we have a speaker setup like this:

NOTE: the center channel speaker array is powered so for this question it just uses one of the four sends in our snake. The other speakers are passive. their make is Peavey Impulse 1012 at 8 Ohms.
The way they are currently circuited is like so:

All of this comes from one amp, a Peavey 1500. We also have a Peavey CS 800, and a Peavey 300 series monitor amp.

So to my question...
What is the optimal way for me to be able to have maximum power to those four speakers using at max 2 snake sends using the 1500 adn the 300? The other two are for Powered speakers and monitor speakers. I would like to be able to use the CS800 for multiple zones such as lobby announcements and actor calls.

The only way to circuit the upper speakers is with 1/4" cable. the lower speakers can be connected with speakon ports.
If pictures are helpful thay can be posted.

thanks in advance!

 

[museav]

What is the purpose of the four speakers and what are the actual dimensions of the space? And I am not sure I understand the circuiting, how do the speakers actually connect, are there four cables back to the amp or do they all tie together somehow at the one speaker location?

The PR15 is a nominal 8 Ohm speaker rated 200W continuous, 400W program and 800W peak. The PV1500 is rated (all EIA ratings) 500W per channel into 4 Ohms and 300W per channel into 8 Ohms in stereo mode and 1000W into 8 Ohms for bridge mode. If you want two speakers per channel then one choice is the two speakers in parallel on each channel of the PV 1500, thus 500W per channel or 250W per speaker. You could mess around with a second amp any maybe get a couple of the speakers up to 300W but that is a 0.8dB difference and no one would hear the difference.

 

[cnnrward]

What is the purpose of the four speakers and what are the actual dimensions of the space? And I am not sure I understand the circuiting, how do the speakers actually connect, are there four cables back to the amp or do they all tie together somehow at the one speaker location?

The PR15 is a nominal 8 Ohm speaker rated 200W continuous, 400W program and 800W peak.

I was wrong about the speaker make, they are Peavey Impulse 1012's.
allView attachment 8973

The top left is the input and each of the other ports are wired to the other speakers. The purpose is to provide sound to our 1500 seat auditorium.
The current setup works, (bridge mode from the PV1500) but the amp is pushed up too high for my liking. The PV1500 has overheated in the past, and I am trying to prevent that from happening in the future.

 

[bishopthomas]

Well, you can put all four speakers on one amp. Set your amp to stereo to drive each pair of speakers from separate amp channels. This is probably why your amp has gone thermal in the past. Now you have two options: You can do a Left/Right setup where the two speakers on the left side are on one channel and the two right speakers are on the second channel. The other option is to put the front speakers on a channel and the rear on the other. This will give you the option of balancing the speakers as needed. If you do this you'll want to run in mono, otherwise the left side of your console is driving the fronts and the right will be driving the rear. This will work basically, unless you are using a console with stereo channels that are fixed as hard panned.

 

[cnnrward]

Well, you can put all four speakers on one amp. Set your amp to stereo to drive each pair of speakers from separate amp channels. This is probably why your amp has gone thermal in the past. Now you have two options: You can do a Left/Right setup where the two speakers on the left side are on one channel and the two right speakers are on the second channel. The other option is to put the front speakers on a channel and the rear on the other. This will give you the option of balancing the speakers as needed. If you do this you'll want to run in mono, otherwise the left side of your console is driving the fronts and the right will be driving the rear. This will work basically, unless you are using a console with stereo channels that are fixed as hard panned.

I understand what your getting at, but the problem is that our amp is in the control booth, and our snake is only in XLR. We dont have a good way to split a mono signal once it is on the stage. Used to have our amp onstage, but the stage isn't secure and people with no knowlage would mess around with the equipment, breaking both the amp and speakers. Is there a good way to split the Stereo XLR into 4 1/4" lines?

 

[museav]

The top left is the input and each of the other ports are wired to the other speakers.

What ports? What you need to find out is how they are actually wired

The purpose is to provide sound to our 1500 seat auditorium.

You have the center channel array and in your sketch these seem to more be effects or surround speakers. If the side speakers actually are where you show them and they are all getting the same signal and that signal is also going to the center channel then you might just be better off to not use the side speakers.

The current setup works, (bridge mode from the PV1500) but the amp is pushed up too high for my liking. The PV1500 has overheated in the past, and I am trying to prevent that from happening in the future.

This is why it is important to know exactly how the speakers are wired. If all four speakers are wired in parallel and you only have one line to them then you have a challenge as you would have a nominal 2 Ohm, and probably less than that at some frequencies, total load to the amp which is not a load the PV 1500 is rated to drive in any operating mode.

I understand what your getting at, but the problem is that our amp is in the control booth, and our snake is only in XLR. We dont have a good way to split a mono signal once it is on the stage. Used to have our amp onstage, but the stage isn't secure and people with no knowlage would mess around with the equipment, breaking both the amp and speakers. Is there a good way to split the Stereo XLR into 4 1/4" lines?

A XLR is usually used for one balanced channel rather than stereo but more critically, are you saying the amp output is run on the XLR snake? If so that's just asking for problems especially with the very low impedance it sounds like the amp is driving and potentially including a fire. It actually sounds like what you have now may be worse than what anyone could have done playing with the amp on stage.

 

[cnnrward]

To all,
Sorry for the misunderstanding, the view isn't top-down [plan view], but from the position of the audience [elevation, front].
For the top down [ground plan] view look here:

museav,

To answer you first question:

The second:
The upper speakers are for the balcony, and the lowers are for the main floor. We recently added the center channel for reinforcement because the acoustics are horrible. Our auditorium was built in the 50's and in the 80's they added sound baffles. But the management painted over them rendering them useless. The proscenium is 40' wide and with two speakers on each side the center of the auditorium was unable to hear most of what was going on. It was decided that a center array was needed. It is mainly used for the occasional school assembly, choir events, band events, and our once-a-year proscenium show.

fourth:
via the 2nd pic of this post, the amp is only providing mono amplification and it is being split in parallel among the four passive loudspeakers. The fire theory is very concerning.

My thoughts:
if we moved the amp back to the stage, can we use both the banana plug connectors and the speakon connectors at the same time in stereo mode? That way we could run the banana plugs to the lower speakers, and the speakon plugs to the upper speakers? Or would it be better to run it in Bridge mode and do the same thing? The problem with bridge mode, as i understand it, is that it is best that the speakers would be wired in parallel. Running in bridge mode would require that we use a splitter so that the one speakon port could service the two outside upper speakers. Also, can i still run the two lower speakers in parallel whatever the configuration?

Or should i do this this:

Would this move the impedance back to 8 Ohms?

 

[museav]

Connor,

Thanks for the additional information. You may always struggle with that setup as long as you have just one feed to the four speakers. Along with all four of those speakers wired in parallel resulting in a 2 Ohm nominal and 1.6 Ohm minimum impedance, which as far as I can tell your amps are not rated to drive, you have no way of independently adjusting the balcony and main floor speaker levels.

I also have to wonder if having now five sources of the same content in a live room is actually hurting intelligibility more than helping it. You might want to consider something like not using the two Peavey Impulse covering the balcony if the new center speaker covers the balcony sufficiently by itself.

 

[Spresley]

My thoughts:
if we moved the amp back to the stage, can we use both the banana plug connectors and the speakon connectors at the same time in stereo mode? That way we could run the banana plugs to the lower speakers, and the speakon plugs to the upper speakers? Or would it be better to run it in Bridge mode and do the same thing? The problem with bridge mode, as i understand it, is that it is best that the speakers would be wired in parallel. Running in bridge mode would require that we use a splitter so that the one speakon port could service the two outside upper speakers. Also, can i still run the two lower speakers in parallel whatever the configuration?Would this move the impedance back to 8 Ohms?

Connor - my initial thoughts is good on you to get some information here, but I'm afraid that is all over your head at the moment, and as others have stated you have a real potential to a) hurt someone, or cause damage to the building and or equipment. First thing - you should not run amplified power up at snake, unless the snake has 12 gauge speaker line incorporated in it, and I doubt you have that. Get the amp back closer to the speakers (backstage) lock it up in a cage if you have to to avoid tampering . Get bridge mode out of your head, 4 speakers run bridge mode would drop the impedance way too low. I am assuming your monitor speakers are powered - if not just insert the amplifier you are using for monitors in the signal chain (in red) on my diagram.
If you have a matrix available on your console , I'd run the center fill using that, and possibly the balcony. If you only have left and right ouputs, I would hook it up as per my diagram - this would allow you to blend the lower speakers vs the upper speakers via the left and right master faders. You should have at least an aux out to spare to send to the center channel - this might help you define the material you are trying to broadcast.... My diagram also allows you to use the cs800 for your lobby (you could feed signal to it from the 1/4" SIGNAL outputs from the CS1500, and attenuate the signal using the volumes on the front of the CS800. Be safe , get this switched.