WATT Calculation

[jferello]

So I have a Phonic PowerPod 780 Plus which states the following stats. FYI this amp has (4) outputs oin the back, two per channel.

2x200 @ 8 ohms
2x300 @ 4 ohms

Currently I have (4) Phonic SEM 715 speakers which state the following:

RMS = 230w
Program = 400w
Ohm = 8

I am looking to move into some more power, but I need to verify some things first. Would the following statements be true.

1) If I hook up all (4) speakers to the amp above, would I be pulling 150w per speaker @ 4 ohm each?

Any way to get more power out of this system? By either replacing the amp or the speakers? I would love to be able to re-use something from this setup if possible.

On the other hand what would be a good set for 300w per speaker, utilizing (4) speakers? Again, if possible a powered mixer.

[bgavin]

Originally Posted by jferello

So I have a Phonic PowerPod 780 Plus which states the following stats. FYI this amp has (4) outputs oin the back, two per channel.

2x200 @ 8 ohms
2x300 @ 4 ohms

Currently I have (4) Phonic SEM 715 speakers which state the following:

RMS = 230w
Program = 400w
Ohm = 8

I am looking to move into some more power, but I need to verify some things first. Would the following statements be true.

1) If I hook up all (4) speakers to the amp above, would I be pulling 150w per speaker @ 4 ohm each?

Yes.

Any way to get more power out of this system?

No.

The ability to drive four 8 ohm cabs to 150w per cabinet is decent.
Most of the noise is made by the first 100w, and many cabs won't go more than 150w before they fart out.
Jumping from 150w per cab, to 300w per cab is only a +3dB gain, barely noticeable.
Your cabs won't go 300 watts each, neither will your electronics.

Your speakers are rated at 98 SPL.
Replacing each with a D410-XLT would make the total sound almost twice as loud.
It would be fun to see your amp driving four D410-XLT at 8 ohms each.

Is this bass or PA use?
If PA, go horn loaded if you need more noise.
You will need a trailer and truck to haul the horns, so you might as well spring for big power amps, crossovers and a console.
It gets away from you pretty quick...

[jferello]

bgavin,

Thank you so much for the information. I think I understand most of what you said.

Question though, as you say my current speakers are rated at 98db, but the 410 is only rated at 106db, does that 8db make that much difference?

I use this for side DJ'ing, so its mostly all music, not Guitar stuff.

The reason I was looking for more power is that recently I did a fairly large ballroom and people were asking for me to turn it up and I was hitting the red indicators on my meter every now an then, so I figured I should prolly get more power.

Is there anything between what I have now and the 410? That is a huge jump, like $150 cabs to $1200 cabs....

If you had some time and didn't mind, could you recommend a new amp and speakers that would be a good portion better? Or do I need to start going to one amp to one cab at this point?

Thanks!
Justin

[bgavin]

The 98 SPL spec of your cabs tells me they don't have much bottom end.
The first thing you can do for free, move your cabs into the corner.
This produces a huge boost in the bass response over free standing or mid-way on a wall.
I would stack all four vertically in a corner, so the mix is uniform across the dance floor.
Experiment with stacking each on its side, so the woofer and horns line up vertically.
This may/may not mess with your horizontal distribution with the horn vertically oriented, but it will make them into more of an array.

DJ cabs are full range with a lot of muscle around 50 Hz.
I've run several popular DJ tunes through a signal analyzer, and find strong dub and kick in this range.
4x10 are not at all appropriate for your use. They are just more sensitive and make more noise per watt.

Yes, +8dB makes a huge difference. +10 is heard as twice as loud.
It takes 10x the amplifier power to jump +10dB.
dB = 10 LOG10 (Power1 / Power2)

For your rig, run at 1 watt, then jump to 10 watts.
Input a sine wave at 100 Hz, set voltage at the cab to 2.83 volts.
Mark the dial with removable console tape.
Turn up the volume until you get to 28.3 volts, make a 2nd mark.
Move back and forth between the two marks, hear what +10dB sound like.