ohms vs watts

i have two 15" dual 4 ohm subs. is it better (for loudness) to run 450 watts bridged 4 ohms or 250 watts 1 ohm single channel? and if you know, please explain why more watts or less ohms is prefered.

The impedance (ohms, load) on an amplifier is what causes it to make power.  A lower impedance will make the amp work harder and produce more watts....a higher impedance will cause the amp to work less and produce less watts.  Read up on Ohm's Law.

Loudness is watts...(along with the enclosure, the car, the damping, the speakers...).  450 watts is louder than 250 watts and it doesn't matter what impedance the amp is getting...watts are watts.  You choose the loudness (watts) according to your overall system setup and your individual preferences.  How you get those watts is determined by the coils configuration of the subs and the amplifier that is going to power them.  Generally, subs are driven at a 2 ohm load into a mono amp...most output with least power input.  But they can also be driven by a stereo (2-channel) amp at a higher 4 ohm impedance.  The stereo amp will use more of your car's power to operate.

And BTW, you're not going to achieve a 4 ohm load with two DVC 4's.

I agree with what stevdart said.  Stevdart is the man. 

I do, however, take exception to the above quote.

Loudness is the intensity of a sound as perceived by a human.

Power driven through a speaker produces sound pressure.  Power is represented by a unit called a watt.  An increase in wattage directly correlates to an increase in SPL until any number of physical limits are approached.

So, loudness is not watts. 

Watts help product SPL.  SPL affects (perceived) "loudness."

So, the more accurate statement would probably be:

"Watts directly affect potential loudness, limited by everything else physical. "

Hi. :-)

Damn kfr01, that is exactly what I was trying to say but I couldn't put it into words!   :)

Where you been, boy?

And I had too much higher math clouding my brain...

Not what I said, anyway.  Watts, not ohms, is the deciding factor for "perceived" loudness (okay, kfr01? ;).  The ohms is just what the subs will wire to and what the amp does with that load.  In fact, the lower the ohm load the worse the amplifier will perform.  Look at this Ohm's Law formula:  I X E = P

Power in watts is the result of amps times voltage.  Amps is the word we use for current.  Voltage is not current.  Voltage, when high, means that the amperage can be low to achieve the same watts output.  When the voltage is low, the amperage has to be high to achieve that output.  Amperage makes an amplifier work hard and run hot, and the result is that the specs deteriorate.

So to answer your question more directly, NO...running at 1 ohm is not the best way to do it. 

But here's the problem...you have to become familiar first with the different types of amplifier classes and what impedances they can work with.  This will not be achieved in this thread, I can assure you of that.

kfr01, I meant Roy!