I'm not too hip on the whole 2 ohm 4 ohm thing when it comes to amps and subs and I am in need of some enlightenment! Say I've got 2 12" 4 ohm subwoofers (RMS 50-250), and one 100Wx2 @ 4 ohm RMS amp. From what I can understand, I can make the amp play at 200Wx2 @ 2 ohm RMS without damaging the subs?? Or why would I even need two seperate channels for subs if bass is mono, couldn't I just bridge the amp and play it at 400Wx1 @ 4 ohms RMS (considering both subs will be in one enclosure wired together with a combined peak RMS of 500W)? Now here's a kicker of a question...what if i wanted to power a pair of tweeters as well? I'd need a 4 chan amp, bridge 2 of the chans to go to the subs and the other two going to the seperate tweeters? Ack help im confused!!

 

Munkey-
Take amp and speaker power ratings with a grain of salt. These numbers are guidelines only, and are mostly dependent on how much power an amp will put out without distorting or how much a speaker can handle without blowing. The major factor is the resistance of the speaker load. A 2 ohm speaker will pull twice as much power as a 4 ohm speaker, and an 8 ohm will pull half. In theory, your amp should be able to put out 800 watts at 1 ohm, but this would most likely clip out and smoke the internals of the amp. It doesn't matter whether you run two channels unbridged or a single channel bridged (with the speakers hooked up in parallel). Power output should be similar, because when you hook up the two speakers in parallel, your speakers will act like a single sub with a 2 ohm resistance.

In theory, you might be able to get more power with the bridged setup, but it looks like your amp runs out of gas at 400 watts. This would be 400W X1 @ 2 ohms because the speakers are hooked together and act as one. In this case, each speaker would pull 200 watts, which is within the safe limits for your subs. With a bridged setup you only have to run one set of speaker wires but they have to be twice as big.

The bottom line is you can hook up the subs whichever way you want.

Jerm

P.S. I don't think its a good idea to run a single 4 channel amp to power the tweeters and the subs, because you would need a crossover to separate the signals. You would also waste money because the subs need a lot more power than the tweeters, but most 4 channel amps have the same power output on each channel. Your tweeters don't need 400 watts. I would get a crossover and run two separate 2 channel amps.

 

Assuming your subs are SVC(single voice coil) andyour amp is not 1 ohm stable, you would most efficiently run it at 2 ohms. How you do that is in the wiring of your subs. You would need to brigde your amp to run most efficiently.
henry
94 f-150 302
2 rockford fosgate hx2's and fosgate power 800.2 amp

 

Thanks for yor your help! So I can pretty much wire them how ever I want to, just what I needed to know. The tweeters arent going to be installed anytime in the near future, but when they are, they will be run off their own little amp. Thanks though!

 

OK, I'm going to have to disagree on this one.
If your amp is bridgeable, it is rated at ---watts X 1 into 4ohms. (unless it is a really high-dollar amp) If you connect your two 4ohm subs in paralel, you will be presenting the amp with a 2 ohm load which is out of it's rating. It will work, but the amp will run hotter, clip easier, and probably won't last long.