I had a talk with a couple of shop workers today and I just wanted to double check on a few things they said because I didnt really understand after I left. If I bought a 4 channel amp, the guy said I could run 2 channels at 4 ohms and the other 2 at 2 ohms. Is that possible? Also I had a question on bridging. The guy said that when you bridge two channels, it doubles the power. Does that mean it doubles the power of one channel or the two combined?

 

Yes as long as the amp is capable of driving a 2 ohm load.

When you bridge an amp, you technically don't "double" the power. What you do is take the power of 2 channels and make it 1 channel.

 

I was planning on getting an image dynamics sub 12" that runs at 350 RMS and buying a 4 channel amp to run the sub and set of components. The amps I were looking at was the
Fusion FP4500X
65x4 @4 ohms
125x4@2 ohms

Autotek SX475
75X4@4 ohms
100x4@2 ohms

My compents run at 4 ohms and the sub comes in 2 or 4 ohms. If I'm planning to bridge two channels at 2 ohms, does that change the ohms to 4?

Another option I was considering was just buying a one channel amp for the sub which is a
US Acoustics USX600d
375x1@2 ohms
and maybe get an amp for the speakers later.

 

are you saying you want to run the amp in a "Trimode" operation? as in, powering your sub and your speakers from 1 amp?

the hook up is

each channel gets a speaker (4ohm load) and the sub gets 2 ch combined into 1 so that is 4ohm // 4ohm = 2ohm, but this is 2ohm stereo which is the equiv to 4ohm mono
________
Zoloft Lawsuit

 

if you do it this way (trimode), remember you've gotta use an external LP filter on the speaker wires going to the sub.

Actually if you only power the front component sets, you don't need to use trimode with a 4 ch amp. Just use 2 channels to drive your component set, then bridge the remaining 2 ch to drive your sub. If you do it this, just make sure that the "ohms" work out correctly.

 

Anybody heard anything about concept? Thats what I was thinking of running.