100.4 at 2 ohms bridged?

Posted April 15, 201015 yr

I understand that the 100.4 is 4 ohm stable when bridging. My question is, say I were to bridge the amplifier at 2 ohm putting out the same power as if it were at 4 ohm. So 320 x 2 at 2 ohm instead of 320 x 2 at 4 ohm. Would this still be unstable? The speakers are rated at 320 watts rms as well.

The reason I am asking is I can get the same speaker in a 2 ohm version at half the price of the 4 ohm version.

Thanks guys!

April 15, 201015 yr

The problem isn't so much "power" as it is current.

Even though the power may be the same, the amplifier has to output more current when driving a lower impedance load (basic fact of Ohms Law). The required increase in current may exceed the capabilities of the amplifier.

I personally wouldn't chance it. Jacob may disagree however as he would have a better idea of the current capabilities of the amplifier.

April 15, 201015 yr

Author

The problem isn't so much "power" as it is current.
Even though the power may be the same, the amplifier has to output more current when driving a lower impedance load (basic fact of Ohms Law). The required increase in current may exceed the capabilities of the amplifier.
I personally wouldn't chance it. Jacob may disagree however as he would have a better idea of the current capabilities of the amplifier.

This is true. I never really factored current draw into the situation. Hopefully Jacob will chime in and give me some good news. I don't want to have to buy 2 100.4s lol.

April 15, 201015 yr

The problem isn't so much "power" as it is current.
Even though the power may be the same, the amplifier has to output more current when driving a lower impedance load (basic fact of Ohms Law). The required increase in current may exceed the capabilities of the amplifier.
I personally wouldn't chance it. Jacob may disagree however as he would have a better idea of the current capabilities of the amplifier.
This is true. I never really factored current draw into the situation. Hopefully Jacob will chime in and give me some good news. I don't want to have to buy 2 100.4s lol.

He is referring to the current that needs to be produced by the output FETs. FETs have a rating on how much current they can produce. If the amp was designed to do so, it would have the FETs to do it. But not being designed to do it why spend the extra money to put them in. This isn't saying the amp isn't strong but just not WAY over built.