Was my amp the main reason why my subs are blowned ?

J450nZ

Hi I bought a pair of discontinued 10 inch polk momo. Thing is, I think they were used cause they were placed in a dented box, plus he had to resealed a sub cause there was a leak. My subs and my system was installed by my friend but he knew what he was doing. Everything worked fine and my polk momo were fine until the day after, one was already blowned. My amp is a Alpine MRP-M1000, and the polk holded 300rms but the guy told me at the store they were 400rms. Anyways, he told me to buy a 500 watt amp but my friend told me that they wont go full capacity so i bought the Alpine amp which is 1000w. My friend told me to buy the 1000w but just turn it down a little. He tuned the amp and everything. After maybe 3 hours of listening to music, not to loud, the next day, one sub blowned... I got that one under warranty and got new polk mm 1024 because the momos were discontinued. Anyways, some other guy at the store told my amp was way to huge. so he turned it down to my one sub left which is my other momo left. He tuned the amp down for the single sub. It worked for one week, I listened maybe 7 hours of music and it finally blowned. The guy at the store told me to cool it and not to put the music loud. Point is, I didnt and it blowned. Now i am mad as hell and I only got one sub on the warranty. And now I am ordering a new polk audio mm 1024 that are 350rms and im scared that my amp is way too big for the subs. Was my amp the main reason that why the subs were blowned ? Appreciate your word everybody. Thanks in advance. Ps: Also tell me what to do. lol

nguyendot

It's almost never the amp's fault that a sub blows, but an uneducated user. When it comes to running subs, you always want more power than the subs can handle. That alpine amp is 1000w into 2 ohms. You had 2 old momo subs that were probably 4 ohms each. If wired in parallel that's 2 ohms, which would have tried to pull 1000wrms from your amplifier. To push your subs I would have put 600-1000 watts TRUE power (without clipping).

Keep in mind everyone assumes if they buy a "1000w" amp that it actually puts out 1000 watts. Your car probably has a 100-120amp alternator. The car uses between 40-60 amps while running, more if it's running air conditioning.

With that in mind, to get 1000 watts your amp will draw 1000w/14.4v=69.4 amps assuming 100% efficiency. The MRP-M1000 i believe is class D, which is 70-80% efficiency, so 69.4/.70=99.21 amps. I would find it hard to believe your charging system can provide 99 amps unless you have another alternator (even extra batteries would run your system at 12v, which would increase amperage draw).

No knowing this, your amp probably tried to pull more power than was available (even if not at full volume) and clipped or distorted, killing your subwoofer.

My advice? Get the most powerful amp you can get and never turn the gain higher than half. Upgrade all your power wiring from your alternator, battery, and ground.

Amp can never be too big for the subs honestly. I've never had a good amp blow a sub.
Even with a crappy amp, if you use it right and don't push it too hard (most people don't know what "too hard" is), it should work fine.

tk421

^^ as he said. check gains. match to input impedence. dont use as a volume knob. set head unit to a level where it doesnt clip, then turn gain to match the hu's preamp output. that should eliminate clipping. clipping cause DC current to flow tru you speakers. speakers are designed for AC, and died when DC passes tru.