70v system

[Josh Scott]

I am working on a 70 audio system for our adult classrooms, just want to make sure I am on the right path and I am not missing something. We have 3 class rooms, that can all be combined into one large room. For each room I would like to have two line level inputs (one rca for DVD players and one for iPods or computers) and one mic input. In the middle room I will also add line level input for a mixer if they ever wanted to do a larger event. It will mainly be video playback and voice, maybe for funerals music with a a few vocals and piano.

For processing I was looking at these two http://www.symetrix.co/products/inte...ix-matrix-780/

-or-

http://www.symetrix.co/products/inte...m-combine-788/

For an amp I am hoping to find a used Crown CTS8200 (8 channel amp with 70volt output)

Now where I start to get out of my knowledge, is the speakers. I am planning on using the JBL Control 24c with four in each room.

Any thoughts or ideas?

[Frank DeWitt]

If you are looking to save money by using a used amplifier, look at TOA. They go for very low prices on Ebay have 70 volt output and are very good. They are designed for PA use running 24/7 and have a good record.

Frank

[Brad Weber]

Originally Posted by Josh Scott

I am working on a 70 audio system for our adult classrooms, just want to make sure I am on the right path and I am not missing something. We have 3 class rooms, that can all be combined into one large room.

How large are the rooms? What are the ceiling heights? Can you also combine two rooms, e.g. A/B/C, A+B/C, A/B+C and A+B+C?

Originally Posted by Josh Scott

For each room I would like to have two line level inputs (one rca for DVD players and one for iPods or computers) and one mic input. In the middle room I will also add line level input for a mixer if they ever wanted to do a larger event. It will mainly be video playback and voice, maybe for funerals music with a a few vocals and piano.

Are you thinking of the DVD and iPod/computer inputs being stereo inputs? Would the mixer input be mono or stereo? That makes a difference between it being three microphone and four line level or three microphone and eight line level (four stereo) inputs.

Would the situations involving vocals and a dedicated mixer involve multiple open mics at a 'stage'? Depending on the room size, ceiling heights, room acoustics, etc. you might want to consider one or more 'stage' or 'headtable' zones where you mute or attenuate the speakers in that specific area to increase gain before feedback.

Originally Posted by Josh Scott

For processing I was looking at these two http://www.symetrix.co/products/inte...ix-matrix-780/

-or-

http://www.symetrix.co/products/inte...m-combine-788/

Both very nice products, especially when you also use the associated remotes. However, they, and most matrix DSP products, are not contractor products that require some associated training or experience to wire and program. If you've never used those or similar products you may want to have someone familiar with them available to help you.

Originally Posted by Josh Scott

Now where I start to get out of my knowledge, is the speakers. I am planning on using the JBL Control 24c with four in each room.

This is where knowing the room dimensions and ceiling height are critical as that will affect both what speakers and how many of them may be appropriate. A lower ceiling may equate to not needing as much from each speaker but needing more of them, conversely a higher ceiling typically means fewer, higher quality speakers.

For a 70V system you would want the Control 24CT, the version with the transformer. Depending on the ceiling height those might be fine for background music, but for AV program audio and live events where yo'd have a dedicated mixer then you might want something more. How far you go with that may be budget driven.

[Esoteric]

Hey, if you would like to save a ton, and depending on the speakers needed, I have a ton of used, but still in good shape 70v speakers with transformers that I am unloading very cheap.

[Josh Scott]

Yes the rooms can be combined Ab/C, A/BC, A/B/C, or ABC.

Rooms are 12' tall and 28'x34'

Mike thanks I will keep that in mind but we won't be doing anything until summer.

Typical use would be seminar type uses at most a funeral with piano and two or three vocals. If for some reason I need a full band I would use a bigger sound system.

[Josh Scott]

Here is a very rough drawing