NEED ADVICE ON SETUP

[Haraldkongen]

I am making a battery powered portable full range PA loudspeaker for a festival. I found this amp and speaker, would they match and have good sound and would the speaker hit max spl at 128db? I have two car batteries so around 150AH available
Sure Electronics AA-AB31431 1x750W IRS2092 4 Ohm Class D Audio Amplifier Board

PD-312 PA Speaker 12" 400W

 

[WaynePflughaupt]

Impossible to say with the smidgen of information you gave us. For instance, are you talking 128 dB at the throat of the horn, or 100 ft. away?

A couple of things are for sure: 1) The amplifier power is most likely grossly over-rated. 2) Using batteries, I hope it’s a brief festival.

You’d be better off to rent a generator and get a real A/C powered amplifier.

Regards,
Wayne A. Pflughaupt

 

[markw]

Is this your speaker? http://www.tronios.com/en/pd-312-power-dynamics-pa-speaker-12-400w.html

I found this handy little utility that will give you ax approximate estimate of what you can expect using the sensitivity, power and distance from the speaker: https://www.stageaccompany.com/support/calculator.html

Using a sensitivity of 99db and amp power of 400 watts*, it says you should get 105 db at 10 feet from the speaker,

Please note I'm using the stated 400 watts MUSIC power spec although I'd expect that 200 RMS watts is all that can safely handle. That would return a SPL of 102 db @ 10 feet from the speaker.

lso, keep in mind that each time you double the distance from the speaker, the SPL drops 6 db, so that 102 would be 96 @ 20 feet, 90 @ 40 feet, etc, etc...

I have on idea about how your power would affect anything and I'll make no guess as to what it would sound like though.

 

[lovinthehd]

I played with an spl calculator in terms of the speakers' claimed max spl of 128dB. Using a distance of just 1m from the speaker and 128dB as the result, with 3dB headroom, that would require 1585w (I used a Crown calculator), or 794w without the headroom which just fits in under the 800w peak rating.