Hi,
I am new to the DIY Amplifier world. I would like to setup a passive stereo PA speaker pair that runs on a Class D amp. But I would like to power it directly from a 48V LiFePO4 battery pack.
The speaker I am looking at is something like JBL PRX 425.
Passive 2-way, dual 15" loudspeaker with 1,200 watt power rating at 4 ohms
This is a Burning Man project and we are experimenting with running off of large battery banks vs. running an inverter/generator. We may end up building the baffle and DIYing the speakers if we have time...
I am new to the DIY Amplifier world. I would like to setup a passive stereo PA speaker pair that runs on a Class D amp. But I would like to power it directly from a 48V LiFePO4 battery pack.
The speaker I am looking at is something like JBL PRX 425.
Passive 2-way, dual 15" loudspeaker with 1,200 watt power rating at 4 ohms
This is a Burning Man project and we are experimenting with running off of large battery banks vs. running an inverter/generator. We may end up building the baffle and DIYing the speakers if we have time...
Good morning.
With a voltage of 48 volts, it will be impossible to obtain the nominal power of your hp.
Perhaps choose an amplifier board with + rail, 0V ground, - rail, but you will need an additional battery to generate the negative rail.
But with 98 volts in total, that's still far from the mark.
Another solution...single ended stereo amp board in bridge mode (btl).
last solution used, a voltage booster, buck boost.
Attachments
No sane person would run at 48V without a bridge. But still, 48V barely enough to get 250W into 4 ohm, especially as the battery voltage will drop while discharged.
Also, no idea why you have chosen that exact speaker type, because for its size, it won't provide any bass. The only thing it will likely excel, is being very loud, as the claimed sensitivity is 100dB/W/m, which for a double 15" may be reasonable to assume. But again, no bass, the box is specified 70Hz -3dB. Trying to push it with more power will only lead to the woofers getting outside of Xmax (linear cone excursion) and pretty nasty distortion at mid range.
But don't be fooled, with 250W and 100dB sensitivity, the speaker will be plenty loud (124dB peak at a distance of 1m to be exact). After all, doubling the input power will get you only 3dB more.
No idea, what are the constraints of a "Burning Man Project", or even what that means, but I'd strongly advice to get either a small inverter based gasoline generator, and a proper active PA speaker. That will be the most simple, reliable and economic setup you can get. Unless, what you want is to build stuff and learn while doing so. Maybe, if you want batteries, get a decent quality inverter (48 to 230V or whatever mains you happen to use) and power the active PA speaker with it.
Also, no idea why you have chosen that exact speaker type, because for its size, it won't provide any bass. The only thing it will likely excel, is being very loud, as the claimed sensitivity is 100dB/W/m, which for a double 15" may be reasonable to assume. But again, no bass, the box is specified 70Hz -3dB. Trying to push it with more power will only lead to the woofers getting outside of Xmax (linear cone excursion) and pretty nasty distortion at mid range.
But don't be fooled, with 250W and 100dB sensitivity, the speaker will be plenty loud (124dB peak at a distance of 1m to be exact). After all, doubling the input power will get you only 3dB more.
No idea, what are the constraints of a "Burning Man Project", or even what that means, but I'd strongly advice to get either a small inverter based gasoline generator, and a proper active PA speaker. That will be the most simple, reliable and economic setup you can get. Unless, what you want is to build stuff and learn while doing so. Maybe, if you want batteries, get a decent quality inverter (48 to 230V or whatever mains you happen to use) and power the active PA speaker with it.