what ohm should I use for amp/sub?


CarAudio.com Newbie
Apr 2, 2020
I have 12" Infinity Kappa 1200w 500w rms with selectable impedance switch 2 or 4 ohm, and I use Pioneer D-9605 amplifier (sub rms: 350w for 4 ohm - 600w for 2ohm)

which is better using 350w or 600w for the 500w sub?
Is it safe to go over the sub rms (500w).. As some people said that by using more powerful amp you will damage sub overtime? Or 350w is more than enough?
Does the box type will have any rule? ..as I know sealed box need more power than ported one
Last edited:


Nov 4, 2016
Good question - depends on what you're looking for.

Doubling the power, from 350 to 700watts (you're close at 650w) should yield a 3 dB gain in output so there would be a noticeable difference in volume - keep in mind that to double the output volume you would need 10 times the power (3,500 watts). The additional output from going to 650 watts comes as the expense of additional current draw on your system, heat generated by the amp, and typically amplifiers have more control at greater impedance so if SQ is a concern you may prefer the way the amp sounds at 4 ohms.

Based on the rated power handling of your sub and the ability of your amp to drive a 1 ohm load, you'll be fine as long as the amp is in a proper environment (cooling, electrical system capacity) so you could listen both ways. While possible it is far less frequent to damage a speaker with too much power (especially when you're so close to rated) so unless you're heavily overdriving your amp, or feeding your sub 5k, you'll be fine.

Speaker enclosure does play a part, with a sealed box being more forgiving, but a ported box is fine as long as you don't allow the sub to play below the tuning frequency at high power as the box loses the ability to dampen the speaker below the tuning frequency.

Does this help or create more questions?
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CarAudio.com Well Known
Aug 4, 2019
Houston, TX
I’d start at 4. Let the sub loosen up and break in. And if you like it there, leave it. If you want more then drop it to 2. It’ll be fine at 2.
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Think For Yourself, Question Authority - MJK
10+ year member
Aug 12, 2008
sitting on toilet
run it at 2
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CarAudio.com Veteran
10+ year member
Mar 22, 2005
id run it at 2 ohms. it wont hurt anything if you set the amp gain right. heres how. the test tones are at the very bottom...

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