1200w Amp good for 400rms sub?
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=45143
Printed Date: September 11, 2025 at 8:11 PM
Topic: 1200w Amp good for 400rms sub?
Posted By: losangdodgers
Subject: 1200w Amp good for 400rms sub?
Date Posted: December 13, 2004 at 6:42 PM
i have a 12inch kicker comp vr which is 400 rms and a 1200w SONY XPLOD amp to push it. I heard someone on hear saying that you should shoot for 10-15% of the RMS for how many watts the amp should be. Basically what i am asking is....is it safe to continue like this? not at all? or just have to be careful??
Replies:
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:14 PM
anyone????
Posted By: Alpine Guy
Date Posted: December 13, 2004 at 7:17 PM
they should be a pretty equal match up actually.
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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.
Posted By: kfr01
Date Posted: December 13, 2004 at 7:17 PM
It'll be fine if you're careful. Take care to set the gains conservatiely. Run a subsonic filter if the sub is in a ported box.
Is that the RMS rating of the Xplod?
Is the subwoofer dual voice coil?
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New Project: 2003 Pathfinder
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:20 PM
so this is not good? should I think about getting a new amp? or is it okay as long as I dont push it?
Posted By: kfr01
Date Posted: December 13, 2004 at 7:23 PM
Answer my two questions, if you have a chance. :-)
Also state if the voice coils are 2 or 4 ohm.
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New Project: 2003 Pathfinder
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:26 PM
the sub is 4-ohm and dvc and the amps rated power is 200w x 2 and the MAX. power output is 400w x2....about the subsonic filter where would I find one of those besides internet?
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:28 PM
im basically just reading from the box what everything is
Posted By: stevdart
Date Posted: December 13, 2004 at 7:30 PM
The more experienced you are, the more you can deviate from matching power output of the amp to RMS of the speaker. With experience, one might power a sub with twice the output as RMS....on the other hand, someone else might power the sub with one half the output. But as a guiding rule, you should closely match the true power output of an amp to the true RMS of the driver. Take into consideration, of course, that the power output of the amp is dependent on the driver's impedance. Now, some amps are overrated, and some subs are overrated....but the sub is more than likely rated closer to true than the amp might be. A Sony has a tendency to be a braggart, so overrating is very possible. The Kicker is most likely rated true. If you have the Kicker wired to place a 2-ohm load on the amp, you have to look at the amp rating at 2 ohms. That's the matchup you'll be looking for. The best way to make sure you don't send too much power to a driver is to use a multimeter, test tones and knowledge of Ohm's Law to determine the output voltage the amp should be sending. The "10-15%" you heard should be forgotten.
Posted By: kfr01
Date Posted: December 13, 2004 at 7:34 PM
Alpine Guy was right on. You'll be fine. Bridged RMS that amp gives probably 400-500rms. Still set the gain using your brain.
in-line subsonic filter
You only need one if you run a ported box. ------------- New Project: 2003 Pathfinder
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:37 PM
i think i worded it wrong w/ the 10-15%. What i meant was "within" 10-15% of the RMS.
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:46 PM
i think i worded the 10-15% wrong....i meant within10-15% of the RMS. But i guess ill just set the gains down since the guy at the shop told me they were all the way up. When i was choosing my amp, i kept asking them if the amp should be close to the RMS of the sub. He kept saying " no no this is a good amp, you could power two 12in with this" and "oh no it doesnt matter". In the back of my mind I knew they were lying to me just to make the sale but i bought it anyways thinking that I wouldnt push the limits on the sub.
Posted By: losangdodgers
Date Posted: December 13, 2004 at 7:54 PM
alright thanks, im gonna set the gains down a bit and just take it easy.
Posted By: kfr01
Date Posted: December 13, 2004 at 7:54 PM
Wait a second .. you have a 2 channel amplifier and a dvc 4-ohm subwoofer. How do you plan to wire that thing? I gaurantee that amplifier is not stable at 2-ohms bridged. You'll have to wire that baby in series. Then you'll only be seeing ~250w at 8ohms bridged. You'll be more than fine, but under utilizing your amplifier. You probably didn't buy it to send 250w rms to the subwoofer.
I'd probably sell or take back that amp. and buy a mono 2-ohm stable class d subwoofer amp. Whoever sold you that amp gave you bad advice, imo.
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New Project: 2003 Pathfinder
Posted By: stevdart
Date Posted: December 13, 2004 at 7:58 PM
^^^ditto. That salesman was a true idiot.
Posted By: losangdodgers
Date Posted: December 13, 2004 at 8:08 PM
dvc means that the sub is 2ohm automatically? Because the sub i have is just 4ohm. Im not sure if you added anything else. If so i messed up in typing there when i wrote "dvc 4ohm" and not just "4ohm". But they installed everything for me since I wasnt sure how to. If i knew i would have. But I have had the sub since Saturday and I havent been turning it up full power at all. Seems to work fine.
Posted By: stevdart
Date Posted: December 13, 2004 at 8:11 PM
?????????? You had the system installed and everything seems to be fine? What is the purpose of the post?
Posted By: losangdodgers
Date Posted: December 13, 2004 at 8:18 PM
i wanted to know if the amp was safe to be pushing the particular sub because I didnt want to find out in the long run that i blew the sub because of that. Thats why i havent been turning it up full power because i wasnt sure if it would be good for it. Thats why I posted to ask if it was safe or not.
Posted By: kfr01
Date Posted: December 13, 2004 at 8:18 PM
Last I heard all kicker comp vrs are dvc.
DVC can't be "just 4-ohm." It depends on how you have it wired.
If you have the dual 4-ohm version your amp's days are numbered unless you have it wired in series at 8-ohms or each channel to a voice coil.
So, how do you have it wired?
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New Project: 2003 Pathfinder
Posted By: losangdodgers
Date Posted: December 13, 2004 at 8:22 PM
im not sure how he wired it at all I guess ill go back and find out but if so then ill probally get a new amp suitable for the sub.
Posted By: dedlyjedly
Date Posted: December 13, 2004 at 8:31 PM
what model # sony amp is it? the guys were right before, most sony stereo amps are not stable to a 2 0hm mono load. dont worry though, you have options. for what i would assume to be around the same price you can find a sony xmd500x. this is a mono amp running 500 rms @ 2 ohm mono or you could spend a little bit more and find a better performer such as jl, phoenix gold, etc... i know it sounds funny but the load (subs) you show (hook up) the amp will greatly affect how it performs. ------------- MECP certified, 5yrs experience, you probably otta listen bitch!!
Posted By: stevdart
Date Posted: December 13, 2004 at 8:33 PM
The installer told you the gains were set all the way up. Not a good install. Go ahead and be proactive in this and take it back. Talk to the supervisor and get a second look at it.
Posted By: losangdodgers
Date Posted: December 14, 2004 at 12:06 AM
the amp is: SONY XM-2200GTX
Posted By: kfr01
Date Posted: December 14, 2004 at 12:14 AM
Yep.. 2-channel. You should check how he wired it.
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New Project: 2003 Pathfinder
Posted By: losangdodgers
Date Posted: December 14, 2004 at 12:37 AM
ill probaly go tomorrow then, what should i tell the guy? He doesnt speak fluent english it was hard to understand what he was saying but there were around 7 workers there who could speak fluent english. I dont know the difference between bad wiring and good. So I would rather go back to the shop I just dont know how to explain it to them to make them understand that it is not the proper amp for the sub.
Posted By: kfr01
Date Posted: December 14, 2004 at 1:00 AM
Not sure what to tell you there. You could look at how it is wired and tell us.
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New Project: 2003 Pathfinder
Posted By: pimpincavy
Date Posted: December 14, 2004 at 11:24 AM
Maybe its just me, but I think I would want my system to be installed on someone who has a grasp on the english language...
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