Does RMS wattage change with impedance?

[jls7884]

I am looking at getting two Polk Audio MM1240 DVC subwoofers and in order to match an amplifier I need to know the total RMS wattage which by adding the RMS wattage of both I get 850W. My question is does wattage change with impedance for example if I wanted to wire it for a 4 ohm load vs a 1 ohm load?

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[ThatChevyGuy 5,000+ posts]

I am looking at getting two Polk Audio MM1240 DVC subwoofers and in order to match an amplifier I need to know the total RMS wattage which by adding the RMS wattage of both I get 850W. My question is does wattage change with impedance for example if I wanted to wire it for a 4 ohm load vs a 1 ohm load?

on the amplifier it will, not the subs.

 

[iSteven 10+ year member]

I am looking at getting two Polk Audio MM1240 DVC subwoofers and in order to match an amplifier I need to know the total RMS wattage which by adding the RMS wattage of both I get 850W. My question is does wattage change with impedance for example if I wanted to wire it for a 4 ohm load vs a 1 ohm load?

Exactly what the other guy said, impedance through the amplifier will change its RMS output. Finding your final impedance on subs together, then matching ur impedance and wattage with the proper Impedance and wattage on a amplifier.

 

[jls7884]

on the amplifier it will, not the subs.

That makes sense. Polk Audio has 2 mono blocks the PA880 and the PA D1000.1. I have heard as you lower the impedance the sound quality decreases. Is that true?

So, my final question is should I:

1. Get the dvc subs and wire to 1 ohm with the PA D1000.1

2. Get the svc subs and wire to 2 ohms with either amp

3. Go with another amp that can supply the sufficient RMS wattage at 4 ohms

 

[T3mpest 10+ year member]

Theoretically there is a difference for most amps, but it's something a machine can pick up, not human ears.. Also, the subs themselves present WAY more distortion than the amps lowered impedance will. Get what fits the budget best, likely a single amp wired at 1 ohm.

 

[lordamun2012]

I have a pa880 I am repairing, it fried the two main caps, the six irf540n's, the op amps, one photocoupler, one 5 watt resistor, the pwm and a the transductance amp a few other caps! I have found a bunch of these have suffered the same fate! You can always look into soundstream, they have some nice ones on ebay for under $250 that will handle the 1 ohm and are class d, cutting down on size! Also remember rated resistance is different than actual resistance, you can use an ohm meter to check your setup, 4 ohms can actually be as low as 3.66 on a coil! I did notice that sonicelectronix does not list the actual impedance on the MM1240DVC but they have them $169 each, they also have picasso p1.1500d for $171, unlike the polk for $229!