Question about Voltage Formula for determining Amp Gain

[fazio93]

If Voltage of the output = sqrt(RMS Power X impedance of the speaker)

I have a Kicker 12" 800 Watt 4 Ohm Dual Voice Coil Comp VR. I have it bridged down to 2 ohms.

But if I want to determine the needed output voltage from the amp, would I use the 4ohms that the sub is rated for (which would make the needed voltage 40 V) or do I use the 2ohms that I have it set it up at (which would make the needed voltage ~28 V)

Thanks

[IH8PunkRok]

if its wired to 2 ohms then thats the number you need to use

[hdorre]

if its wired to 2 ohms then thats the number you need to use

x2

[TeejayBee]

You dont have it bridged down you have it wired in parallel from dual 4 to 2 ohm final load and use this chart

http://i53.photobucket.com/albums/g42/Krannyman92/rmschartpm5.jpg

[fazio93]

ok, thanks.