Wiring up 2 low power PA's

Sebzy

Hi

On my quest to build a small pa system for a charity event I 'm envolved in I've acquired pair of old amps.

Their low wattage but better than nothing 90W

TOA PA Amp 1061 MONO
http://www.toa.eu/user/data/A-1061.pdf
http://aicsecurity.co.uk/techsheets/TOA%20Amplifier.pdf

I can dig up 4 8Ω speakers (HiFi) no idea what wattage yet as I dont think their marked and was wondering the best way to connect them to the amp's

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]

Or

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]+Series+[SPEAKER3]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]+Series+[SPEAKER4]

Or

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]+Parallel+[SPEAKER3]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]+Parallel+[SPEAKER4]

I'm guessing the speakers I can get will be around 50w each @ 8Ω.
The amps has the following outputs

4Ω@15.5v
83Ω@70v
170Ω@100v

PaulBrewer

Sebzy wrote: »

Hi

On my quest to build a small pa system for a charity event I 'm envolved in I've acquired pair of old amps.

Their low wattage but better than nothing 90W

TOA PA Amp 1061 MONO
http://www.toa.eu/user/data/A-1061.pdf
http://aicsecurity.co.uk/techsheets/TOA%20Amplifier.pdf

I can dig up 4 8Ω speakers (HiFi) no idea what wattage yet as I dont think their marked and was wondering the best way to connect them to the amp's

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]

Or

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]+Series+[SPEAKER3]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]+Series+[SPEAKER4]

Or

Left in from DJ Mixer - [AMP1] Mono Out [SPEAKER1]+Parallel+[SPEAKER3]
Right in from DJ Mixer - [AMP2] Mono Out [SPEAKER2]+Parallel+[SPEAKER4]

I'm guessing the speakers I can get will be around 50w each @ 8Ω.
The amps has the following outputs

4Ω@15.5v
83Ω@70v
170Ω@100v

That's not going to work I think.

The amp is a '100 volt Line' one often used in announcement PAs like you might find in a Railway Station or similar.

The speakers to run with this would have a transformer build into them which converts the signal before it actually hits the speaker. General Hi-Fi speakers wouldn't be appropriate.

PMI

For the money of typing your posts and turning on your PC etc.. you would of hired one

Sebzy

PaulBrewer wrote: »

That's not going to work I think.

The amp is a '100 volt Line' one often used in announcement PAs like you might find in a Railway Station or similar.

The speakers to run with this would have a transformer build into them which converts the signal before it actually hits the speaker. General Hi-Fi speakers wouldn't be appropriate.

Yea I know what you mean but that 4Ω@15.5v out I thought might so the trick.

2 HiFi speakers each 8Ω in parallel which should provide an impedience of 4Ω.
Now the question is @15.5 v will that damage the drivers.

PaulBrewer

As I said in my previous post , a 100v line system is designed to run into speakers that have a transformer attached to them.

Sebzy

PaulBrewer wrote: »

As I said in my previous post , a 100v line system is designed to run into speakers that have a transformer attached to them.

Sorry Paul but maybe I'm missing something here. Sure there is one output rated at 100v but I'm talking about the 15.5v line.

Even if I could find out what voltage HiFi speakers ran at I could throw a step down transformer in the circuit.

Thanks

PaulBrewer

Sebzy wrote: »

I could throw a step down transformer in the circuit.

You could ....

Seems like a whole heap of pain for very little gain to me.

The two units aren't designed to be used together.

Savman

Rent!

Sebzy

Savman wrote: »

Rent!

Yea but where's the fun in that.

If I cant bodge together something half decent yea I will just rent something but until then.......

Thanks for the help.

Quiggers

these are 2 different technologies, the speaker is designed to receive a varying voltage
from a transistor based amp, keeping the current fairly static.. this conveys the info, its not simply powering a light bulb, the cable carries high amplitude information, the speakers are a transducers that take the ac signal into acoustic energy.

100v line systems use the opposite principle, keeping the voltage fixed and varying the current, hooking up an 8ohm driver to a 100v amp will simply burn out the voice coil, thats why they need the matching transformer, also no 100v amp is designed to give large volume of a full range signal, they're used for announcements and muzak, tailoring the signal, making it sound as though its coming down a phone line.

why not ask a local pa hire firm to sponsor the gig with a PA, at the very least they'd shave the price for you.

Sebzy

Hey Quiggers your a star
It's a lot more clear now and I'm not going to try hook them up for now.
Thank you very much

Quiggers wrote: »

these are 2 different technologies, the speaker is designed to receive a varying voltage
from a transistor based amp, keeping the current fairly static.. this conveys the info, its not simply powering a light bulb, the cable carries high amplitude information, the speakers are a transducers that take the ac signal into acoustic energy.

100v line systems use the opposite principle, keeping the voltage fixed and varying the current, hooking up an 8ohm driver to a 100v amp will simply burn out the voice coil, thats why they need the matching transformer, also no 100v amp is designed to give large volume of a full range signal, they're used for announcements and muzak, tailoring the signal, making it sound as though its coming down a phone line.

why not ask a local pa hire firm to sponsor the gig with a PA, at the very least they'd shave the price for you.