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View Full Version : Underrated amps?


armedforglory
02-07-05, 07:57 PM
well, it goes like this...

I have heard more than one person say that MTX underrates their amps...dont know if that is just talk, or the reality of it...I was just wondering, because I have two older round 12" SoloBarics rated for 300w RMS each, and I looked up specs on my MTX Thunder 2300 amp, and a couple of different guys said that it puts out ~840-850 watts...I am happy if it does indeed put out that much power, but I want some reassurance that it wont overpower my subs, cause they aren't cheap, and I cant afford to replace them...

also, while I'm at it, I have a question about the wiring of my amp :help: . Currently, I am running both of the speaker wires from the subs twisted together, the +'s together in the right + side of the amp, or left side, w/e.. and the -'s together into the left - side of the amp...now I think that that is called bridged, but I am not sure...whatever it is called, would it be better for me to run the left sub by itself in the left channel, and the right sub in the right channel, by themselves, or would that mess the ohm-load to the amp..I didnt know what to do, so I simply hooked it up like the guy who had them before me did, I figured if they didnt get destroyes so far, that chances are that they are pretty safe...thanks for all of yall's help...yes yall, I am a southerner, I can say that...sorry if it bothers anyone...thanks again!

ridr4lif
02-07-05, 08:39 PM
as for the mtx amp, i believe mtx rates their amps at 12.5 volts and most cars charge at 13.5 - 14.4 so they may produce more power than stated.
as for the sub/amp, what are the voice coil configurations on the subs? dual 4 ohm, dual 2 ohm, single 4 ohm? this will help us help you out.
TEDD

audiobass10
02-08-05, 03:34 PM
I have the MTX 311D and it's rated at 200rms@<hidden> and birth sheet says 267, so they may be slightly overrated..but they definitely put out what they're suppose to.

armedforglory
02-08-05, 03:36 PM
I'd love to help, but I don't know the voice coil configuration...sorry, I bought the subs used in the box that I have them in, so I haven't even seen them out of the box...Is there a way that I can tell without removing one of them??

armedforglory
02-08-05, 03:38 PM
will the fact that they are overrated damage my subs? they are only rated for 300w RMS...I dont want them to be damaged!

audiobass10
02-08-05, 04:05 PM
Not at all..Overpowering subs will not damage them. Distortion is what damages subs. Set your gain properly and never turn the volume above what you set the gain at so that you will not send the amp a clipped signal..which in return sends distortion to the sub.

Ryan from Ohio
02-08-05, 04:21 PM
Ok this misconception on overpowering has to stop.

An RMS rating is asigned for a reason, end of story.

It usually entails as a Thermal power handling. For a short answer if your sub is 200 WRMS and your running an amp rated at 225 WRMS you should be fine.

YOU CAN NOT however go overboard. So running 850 WRMS to a set of 600 WRMS subs is a STUPID IDEA! WARNING WARNING WARNING you are flirting with danger.

This whole misconception is born out of the competition scene where overpowering is acceptable. Its acceptable because the subs are not subject to the excessive power for long periods of time. Thus the coils have time to cool. In an every day driver car (99.5% of us) it is not a good situation.

Be safe, obey the RMS guidelines.

If you want to run your system as such I advise you to turn it off often. Otherwise your running a risk...

Distortion is also a large factor in damage to a subwoofer. Especially when an amplifier clips (sends a square wave to the sub (flat)).

Anyhow :p

audiobass10
02-08-05, 04:52 PM
Ryan, you make a good point. I agree it is BEST to obey rms guidlines on a sub for normal everyday use. I'm glad you backed up w/ some info regarding coils having time to cool down. I must confess...i have fallen slightly victim to the misconception w/ rms power handlings!...( partly because I want to do some SPL competing) I guess it's true you learn something new everyday. To better my understanding i'm going to ask this question: Assuming you are exceeding a sub(s) reccomended power handling by 100-200wrms and even when sending a clean signal to the amp..it boils down to more than just a "clean" signal. The continuous amount of excess heat received by the voice coils on a regular basis could fry the coils?..or the tinsel leads? Ryan, thanks for the good post..lemme know if i'm understanding this fully. Thanks

Ryan from Ohio
02-08-05, 07:45 PM
Continuous overpowering will build up heat in the motor structure.

You will literally burn the coil. The wire used in the coil is fairly small. It is a bare copper covered with a real THIN layer of clear coat. If that layer degrades or burns off you can blow a sub like that and possibly your amp if the sub blows closed (Short circuit).

Very slight overpowering is usually acceptable. Some manufacturers purposely rate the RMS values low to avoid so many burned ('Blown") coils/subs. Some companies find the absolute highest RMS and list it (eD).

Thats been my experience at least :)

armedforglory
02-08-05, 09:00 PM
well, what I said earlier was obviously unclear...the rating for my MTX amp is 600w RMS, but I have heard people say it was more, like as much as 850w, I was merely wondering if they overstated this, or if MTX underrating their amps was gonna kill my subs
my subs are 300 RMS each, and my amp puts out a rated 600w RMS, but I dont know if the extra that MTX conservatively leaves out of the rating would damage either my subs or my amp...thanks for all the help

Ryan from Ohio
02-09-05, 04:06 AM
As noted MTX usually rates their amps at 12.5V. The extra volt usually give it more power.

If you tell me the fuse rating on the amp then we could get a better idea of real world power output.

ANyhow it may be possible that you are supplying to much power....

ridr4lif
02-09-05, 09:26 AM
I can vouch for burning up a voice coil. I live 7 hours away from skool and i was giving a 600rms sub only 420rms...but played it pretty loud for most of the 7 hours. well, it only lasted 6. So if you are going on a long trip, turn the sub off (if you have that option) or just turn the volume down everyonce in a while to let the voice coils cool down.

Ryan from Ohio
02-09-05, 09:44 AM
Box design has an impact also.

Sealed boxes naturally get hotter.

But your sub could have failed due to other reasons also :)

ridr4lif
02-09-05, 10:15 AM
It was in a sealed box...maybe that was "part" of the problem.
TEDD