I recently bought an mtx 942 amp and RF st3 12' sub.(one)
when i install it i was upset because it did not sound like a stage 3 should be . I spend good money on this speaker. I knew the amp was good because my friend has it on his car with weaker kicker speakers and their so loud that he can not put the volumme at full blast(only half).

I thought maybe it is not loud because my box that i had the speaker in, because it was really small in two side of glass. I then decided to make my own box with the mdf and i disconnected my amp.

when I finish with the box i put everything back and i noticed that it did not sound much differently but in a few minutes the amp turn off. what happen was the 4 gauge wire under the hood burn! and fuse was melted.

Then i tought maybe it is the wire so i bought another amp kit and this one has a fuse in the front next to the battery and one next to the amp. after finish replacing the wires it sound too Loud!! it was so loud that i had to open the door. This is what i was expecting from RF. Yet it did not last long because it burn a fuse several times. The fuse that had been burn werefrom one next to the amp.(not the amp but the kit that protect the amp)

everytime i put a new fuse i alter the amp setting to low volume and the amp work good but it is when i put it higher and the amp get really hot from the sides burn a fuse.


Does anyone know what is the problem ? Thank you for your help

 

Hmmmm.. Are u sure your using the right size fuse for that amp? how many watts is that amp rated rms and what size fuse are u using??

Are your speakers wired correctly?

 

you maybe have your +, and -'s wrong, or the speaker isnt efficient enought o run on less wattage, and you do need a bigger fuse and possibly a smaller wire, possibly an 8 guage.

 

Today i change the wire in the amp from Bridge to just regular. This seem to stop the amp to heat up quickly and it does not burn any fuses.

Although this way sound good, I believe that the other way louder but was killing my fuse. Anyone know why??

 

what are the amps specs and the subs specs...might be pushing the amp at too low of an impedence

 

yeah what slick said, but NEVER put a bigger rated fuse in the amp. the fuse rating is there for a reason, and if you allow more current to go through, you can fry the internals.

we need specs on the sub and amp.

the speaker can run fine on less power. efficiency just rates how loud the speaker can play given 1 watt measured at 1 meter. he also doesn't need a bigger fuse than what the amp came with, otherwise he'll risk damaging the amp.

 

The specs for amp are: 175wrms x 2 @ 4ohm, 350wrms x 2 @ 2ohm and 700rms x 1 @ 4ohm bridged all at 12.5v, more power at 14.4v = 940wrms x 1.

And the speaker is an p3 12' with 500rms 1000 peak.(one)

 

is the sub dvc? if so, what ohm per coil?

 

it is 4ohm

 

dvc 4 ohms? so you probably have them wired to 2 ohms final load. and when you bridged it, it went below the amp's stable operating level, and caused the amp to run hotter than normal.

 

Good call ascendent!