Amp thermal overload prevention

[90MTXSHO]

Hola -

This doesn't relate to anything SHO-specific ... but more a general question. I've got a pair of 10" Eclipse subwoofers being driven by an Alpine MRV-T320. The amp is supposedly a good match for the subwoofers, but I find on occation that after having played some bassy (and maybe not even that bassy) music, the amp shuts down. Turn down the volume for a few seconds, amp comes back up. I'm under the assumption that the amp's shutting itself down due to running too hot, so I'm wondering, what can I do to prevent this? Is it a matter of the amp just being overworked? Would mounting some sort of cooling fan pointing on it help any?

In other words - what can I do to prevent the amp from shutting down, or would just a new more powerful amplifier be the best solution?

Thanks!

 

[Slo-Sho]

Is it bridged down to less than 2 ohms?

 

[90MTXSHO]

Nope - it's bridged to 4-ohms (two dvc subs at 4+4 ohms each = 4 ohms), and Alpine's showing it as being bridgable to 4-ohms.

 

[Slo-Sho]

So the subs are 4 ohm/per vc...wired in parallel then series?

 

[90MTXSHO]

each sub is 4 ohms, plus an additional 4 ohms for the DVC, so wiring the sub/dvc in series makes it 8 ohms. Then I have both subs wired in parallel to the bridged amp, making the amp see a 4 ohm load for both of them.

 

[30footSHO]

Clint, where do you have the gain set at? Also, does this happen at night or any time during the day?

 

[90MTXSHO]

Actually happens more during the day than at night. I'm not sure about the gain - I had it installed professionally (I wasn't about to tear into the 6's dash afetr some of the horror stories I've heard ). My guess is, it's probably not overly high, but I can try to take a look tomorrow. I'm not sure if I have the hex key to get to the panel though. We'll see, either way.

Thanks for the replies you guys - I appreciate it!

 

[SHOZ123]

Check you voltage at the amp when under load to see if there is a voltage drop. A fan would help too.

 

[MelectroK]

If you have a 4 ohm load, then bridge it across a stereo amp. The amp then "sees" a 2 ohm load. If you wanna run the amp at 4 ohms you need to brige an 8 ohm load to it.

 

[Slo-Sho]

Yes, your setup as you described would be at 2 ohms. The Alpine MRV-T320 is rated at 220 watts RMS x 1 in bridged mode. I don't know what kind of subs you have other than being Eclipse. If you had it installed professionaly then I'd take it back and b*tch. They may have skimped on the cable size as well. Also, does the amp clip or just shut down w/o occurence?

 

[90MTXSHO]

Sorry all - been busy lately.

The subs in question are the following: Eclipse SW6103DVC (10" Dual Voice Coil 4ohm + 4ohm). I'm a little confused as to why they'd be running in 2ohm and not 4, though. I have the posts wired like this (Image courtesy of Rockford Fosgate):

As for cabling - the cable running to the amp is 8 gauge power (I wish it was higher, but I didn't note that I was planning on adding on in the future, so thats what they gave me), and it looks like the speaker wire might be 14 or 16 gauge.

I just took a look at the wiring config they did. I know the speakers are wired as above, but reversed somewhere along the line so if I plug both speakers in + to + and - to -, they'd be out of phase. Now, the amp's bridged between the two and putting out a lot of base. The gain's at about 1/3 - 3/8ths (a little shy of half). At the line-out converter, one of the RCAs going back are unplugged. I plugged it back in and the bass dropped significantly. I swapped the + and - of one of the subs to see if that fixed the problem, but no dice. The bass got lower and essentially went away. Pulled the RCA, and all was fine again. Just as a test, w/only one RCA plugged in, I swapped the speaker wires and the bass nearly dropped to nothing, so they've got the phase right, it appears.

Now, I'm somewhat confused as to why my volume'd drop so much just by unplugging a cable from the LOC. I suppose I could run into the installers this week and just see whats going on, why it'd be cutting out like it is. And by the way, the amp's completely turning off, not just clipping - the sound entirely goes away.

Ah - such a pain. Maybe I should just get a more powerful amp or something ... or just scrap the whole damn thing

 

[xpnsiv93]

bigger amp...

your running two 10's @4ohms into a 1 channel...thats a heavy load...and knowin the darn installers..(nuttin against any of U) they probably have it turned up...IMHO....bigger amp...i had same issue when runnin my 3 JL audio W-6's...i just got a bigger amp and it went away..and gettin a lil fan to hook up to it doesnt hurt either...like a lil one from an old computer...but thats me..im no professional..but i had experienced that b4...

 

[30footSHO]

I was running two 10s at 2ohms into one channel... but then, my amp could handle 750w@1ohm I hardly would agree that a 4ohm load would be too much for that amp.

Clint, I understood completely what load your speakers were wired for. The gain is most likely in the right spot. For the wattage you are using, 8ga power cable should be just fine. I guess the bigger amp is just the way to go. PM me... I may be able to help you in your quest for more power.

 

[90MTXSHO]

It's just weird, ya know? I mean - in the SHO, sure ... it'd overheat once in a while ... but then again, the floorboard was somewhat rusted, so I may have had a natural fan going back there and not even realized it

Anyway ... I'll have to think about upping the amp power some. Just the idea that I have an RCA unhooked is kinda weird, but that could be courtesy of the LOC they put on.

Oye - thanks again for your help, guys. Confused as I am, it is appreciated