What kind of amp would I need with these subs?

What kind of an amp do I need for these subs?

• I just bought two ten inch MTX subs in a ported box off a buddy, rated at 300 Watts RMS and 4 ohms. I know that I should have an amp that's about 600 Watts since 300x2 = 600 but I'm trying to buy used and can't find anything in my price range that's 600 Watts. Would an amp that is 1000 Watts (like once that I found for a hundred bucks) be way over the top and just blow my subs or would I not have any problems as long as i didn't, say, crank it all the time? Do the ohms of the subs matter as well? Thanks in advance!

• Answer:

  To answer your last question first, yes, the impedance of the subs do matter. For the best power transfer, you want the final impedance presented to the amp to be as low as the amp is able to handle. Power (watts) dissipated is cut in half each time the load impedance is doubled. So an amp that outputs 1,000 watts into 2 ohms would only output 500 watts into 4 ohms. Assuming the subs have single 4 ohm voice coils, you have 2 wiring options: 1) Subs in parallel (both positives and negatives together and then to the amp), with a final impedance of 2 ohms; 2) Subs in series (not recommended) (positive of one sub to negative on the other sub and the remaining positive and negative to the amp), with a final impedance of 8 ohms. The first option is best because it's not recommended to run individual subs in series. It also results in the lowest final impedance to the amp, and the best power transfer, assuming that the amp is stable at 2 ohms. Powering a sub rated to handle 300 watts RMS with an amp that outputs 500 watts can definitely damage the sub. In fact, with some manufacturers, JL Audio for example, the warranty is voided if a sub has been connected to an amp that outputs more power than the sub is rated to handle. As long as the input gain (and especially the bass boost) is adjusted lower and the volume is kept to a reasonable listening level, you should be able to run the subs with no problems. Some people like to have a little "headroom". In many cases, it's probably better to have a little more power than actually needed. That way, it's possible to get the best performance from the subs without cranking everything up to maximum. But, as soon as you start to "find out how loud they'll go", or enter an SPL contest with real competition level products, you're going to blow the subs.