Im banging my head against the wall trying to design my first 70 volt system. I understand the basics and have even installed them once or twice but havent had to design one until now. I am installing this in a sports bar with a total of 14 speakers( 6 in the dining area, 4 in the bar area, 2 out at the patio, and 2 out front). With that said Im looking for a 150 watt 70 volt amp with 8 watt powertaps. I guess I could use a bigger amp to cushion for any speakers not being loud enough.

Is there certain guidelines of what powertap to use in different locations. I know the volume output increases with the higher wattage powertaps but is there a rule of thumb for how much wattage should be allowed for for adaquate volume. The ceilings are 12 feet high and as of right now Im planning on using 8 watt powertaps on standard in ceiling speakers (Id prefer to use 70 volt in-ceiling speakers but cant find any that look decent). This is fine for the in-ceilings but I need outside speakers that have the transformers built in and maybe even selectable wattage taps. All of the 70 volt speakers Ive seen so far are ugly as hell and I want something that is middle of the road for quality and sound that are still attractive.

My second question is I cant seem to find info on whether or not I can use any 2 channel poweramp and add transformers to it or if its all 70 volt specific. All of the 70 volt amplifiers Ive come across look like they have more than what I need. All that I want is something with a on/off switch and gain control located out of reach (if possible). Can I just use any PA amp with a A/V receiver and place transformers at the speakers? The last 70 volt system I installed was all 70 volt specific and it was a long time ago so I cant remember a damn thing as far as the make and model. Ive already searched the forums for answers but was hoping for some clarity.

Thanks,

Yes, depending on efficiency of speaker and noise floor. How rowdy is this bar?

I know the volume

You should look at the JBL Professional or Atlas FAP product.

This is fine for the in-ceilings but

Comment from above still stands.


Buy the correct amp for the job, or you will have the opportunity to visit your customers repeatedly.


All of the 70 volt amplifiers Ive come

Depends on what connections your a/v receiver has. You certainly can put 70 volt transformers at the speaker to convert an 8 ohm speaker to 70 volts.

The last

I suspect you might want to talk to a competent supplier of this type of product. I know at least one that can help. I do not wish to advertise for that company, however.

Thanks for the reply.

Planning a 70 volt system is actually quite easy. Use the JBL 24CT or 26CT speakers they sound decent and look just like "normal" in ceiling speakers. They also make them in box style speakers if the ceilings are open. The "T" means they have transformers built in. There is a rotary switch underthe grill that allows you to change the tap settings. Daisy chain all the speakers, tap them at lower settings for the front and possibly the patio, medium settings for the dining area and the higher settings for the bar. To figure out how big of an amplifier that you need, add up the wattage of each speakers tapped value then add twenty five to thirty five percent more for headroom . 4 speakers at 7.5 w plus 6 at 15w and 4 at 30w plus headroom means you need at least a 300 watt 70v amp. Run all your sources mono to keep from having to stereo pair the speakers and to give you even coverage.

Dirte,

Fred works at the company he is speaking of. Call him, or email the address in his profile and hook up with him. He'll take care of you!

Fred is just nice enough to not advertise his company in every forum on the web every chance he gets.

Fred, I would shoot you an email but you dont have an email adress in your profile. Send me one if you dont mind. Thanks

bump

You can add a 70 volt transformer to any amp. Then hook it up and see if it flames.

I wouldn't do it, except when I was a kid, had no money and couldn't buy anything from a supplier.

You need a BEEEG 70 volt transformer to convert, say, 300 watts of power to 70 volts. If you don't get a huge one, the transformer may overheat but will definitely have poor bass performance. I never thought of this until this moment, but when a 70 volt amp is designed, they can include the output transformer, or whatever they use to make it 70 volt, in the overall feedback loop and thus get pretty good bass performance.


Then why the previous question?

Sent an email earlier this morning to address in profile....