Newbie here, amplifier output?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=72530
Printed Date: September 05, 2025 at 4:12 PM

Topic: Newbie here, amplifier output?

Posted By: never0101
Subject: Newbie here, amplifier output?
Date Posted: February 09, 2006 at 8:06 PM

howdy. i had a question about how different ohm loads affect the output of an amp. i have a Memphis 16-st500d amp, rated for 500w @ 2 ohms. i plan on using this to power a jl10w7 sub, rated for 3 ohms. i was wondering what power the sub would be seeing, since its 3ohms instead of 2 where the amp is rated? thanks for any help!

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2002 Grand Prix GTP
13.65@99.91

Replies:

Posted By: stevdart
Date Posted: February 09, 2006 at 9:25 PM

Find the middle ground between the 2 ohm and the 4 ohm specified ratings (the amplifier will also be rated at 4 ohms). BTW, the sub is not rated for 3 ohms...it provides an impedance of 3 ohms. If you're pondering an Ebay sale and can't find this info, you can probably assume that the 4 ohm output would be at 250 watts. Which puts output at 3 ohms at about 375 watts.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: r_wern
Date Posted: February 10, 2006 at 12:07 AM

Hey! I used to work for a dealer who sold Memphis, and I know quite a bit about their stuff. That amp is way underpowered to run a w7. You should use a MC1000D or, if you are on a budget, at least the PR1000, the entry level 1000 watt Memphis amp. They also make a 2400 watt class D monoblock, but that might be a little much. I'm just assuming you like Memphis....