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.5 ohm stable amp

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=122860
Printed Date: May 31, 2024 at 7:14 PM


Topic: .5 ohm stable amp

Posted By: imtheman0313
Subject: .5 ohm stable amp
Date Posted: July 27, 2010 at 1:24 PM

I kno this subject has been addressed many times, and many ppl have have questions about it..... my problem is finding an amp that can not only run stable pushing .5 ohm....but push 12k w max @ .5 ohm..... everywhere i see ppl asking about 750w and 2kw.....but nothing this powerful.... @4 ohm the amp would have to b at least 2kw.... ive got 2 12" l7s.... dual 2ohm voice coils. and i want to run them both (4 coils) parallel straight to a single channel, preferably a monoblock amp. 750w sub @ 4ohm. x2 1500.. @2ohm=3000, @1 ohm=6000 @.5 ohm= 12k.....give or take..... thats not perfect math considering the coils rnt exactly 2 ohm each, but the theory stands. and i still need an amp that can handle this power.



Replies:

Posted By: DYohn
Date Posted: July 27, 2010 at 1:49 PM
You want to run 12KW to a pair of Kicker L7s?  Hmm, those will last for, oh, about 0.35 seconds.  It's not the amps that need to "handle" the power, it's the woofers.  L7s can handle approx. 1000 watts each, period, no matter how you wire them.  If what you're looking for is to max them out for daily use, I recommend you wire them as 1 ohm loads and then in series for net 2-ohms, and look for a decent amp capable of 2KW at 2 ohms.

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Posted By: haemphyst
Date Posted: July 29, 2010 at 11:01 PM
No. the theory has fallen completely on it's face, before you hit the "Post" button. I think you COMPLETELY misunderstand "power".

No matter HOW you wire them, the woofers will never handle more than they are rated for - 1000WRMS

To run two of them in parallel, you need an amplifier that is stable into .5-ohms, and will make 2000 watts at .5-ohms.

The woofers, wired in series for 8-ohms will handle how much power? That's right! 2000WRMS. In series/parallel for 2-ohms? Guess what? Yep! 2000WRMS again! See if you can tell me how much power they'll handle wired in parallel for .5-ohms? If you guessed 12kW, you are wrong. Nope... 2000WRMS there, too...

Now, if you need an amplifier that makes 2000WRMS into a .5-ohm load, then you need an amplifier that is rated 250WRMS into a 4-ohm load, and is SPECIFIED to be stable into a .5-ohm load.

250 @ 4
500 @ 2
1000 @ 1
2000 @ .5

THAT'S the way the power scale works, in a perfect world. That is AMPLIFIER POWER, not "how much more power a woofer can take just because I wired the voicecoils in parallel" world. Why you are looking for 2000WRMS @ .5-ohms is beyond me. You will get the VERY same output with a respectable 2000WRMS amplifier with the woofers wired in series-parallel and providing a 2-ohm load.

In the old days of "cheater amps", like the venerable Orion 225HCCA, you would be COMPETING in the 4-ohm class @ 50 watt levels, even though you might be bridged into a half ohm, (which they would do, easily, with forced cooling, and upgraded power cables...) and making more than 1200WRMS. Today, however, it's unnecessary to make amps like that.

Get a 2000W monoblock, wire the woofers for 2-ohms, and be done with it.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: imtheman0313
Date Posted: June 05, 2011 at 11:26 PM
NYUK NYUK... sorry for diggin up this thing again, but I jus wanted to apologize to anyone who was offended by my naivete. lol I asked this wen i was jus a wee bit dumber than I am now. lol thx to those who attempted to set me straight





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