Hey guys, for the past 5 years, I've owned a JL Audio 12W6 sub in a sealed enclosure in my trunk, driven by a JL Audio 250.1 Mono sub. I've never had any problems with it, not have I needed to push the amp to clip, go thermal, etc - I've just enjoyed the clean bass from the setup.

Just last week (in literally 60 degree weather), I notice my bass gone and check my trunk. When my car is on, the amp has the thermal light blinking every few seconds. No sound output, no power light, etc.

It has withstood 100 degree summers and 0 degree winters with no problem. Does anyone have an idea of what it may be? Do you think it's about the end of it's lifetime? Should I invest in a new (probably a 500.1) amp for my sub?

Thanks!

 

Open it up. Depending on the amp's construction, it might have some sort of thermal compound between the heatsinks and the output transistors. Maybe it's dried up and all you need to do is clean it and reapply some more.

While you're in there, you can check for any damaged components to see if the problem is being caused by something else.

 

Which JL 250 is it? 250/1, 250/1v2, J2 250.1, or JX 250/1?

 

It's the 250/1. Is the thermal compound simply like... putty? Something that I can pry off and apply more type of thing? I've never run it into thermal shutdown before nor really pushed it.

Another audio shop told me that I was pushing it because it's a 500+ watt sub and a 250 watt amp, although i've never really ran it that hard. I literally turned it on one day and had no bass.

 

Yeah, it's like a putty, goo, sticky stuff a bit. Yup you can just clean and reapply. Just make sure that the transistors are making good contact against the heatsinks.

Lol, that logic is nonsense. The sub rating is basically how much power can it dissipate before the coils get fried. The load it applies on the amp would be the same as a 1000W sub with the same impedance configuration. You're setup isn't the problem here, though a bigger amp isn't a bad idea.

Edit: The more I think about it, the less likely it is that it's actually a heat problem. You powered it up and it didn't work right away huh? Sounds like overheating isn't the problem actually. Instead of opening it, call up JL support and ask them what that flashing light means: I bet that's its way to tell you what the fault is.

 

Well what he's saying is that under powering the sub can be a problem too - when I push the amp, I would be sending a distorted signal to the amp which can be harmful. But again, I don't crank the amp lol.

And I HIGHLY doubt its a heat problem. I've been using it for years in the summers and winters and the day I started it up, it was like 50 degrees when it stopped working haha. Ill give them a call though.

 

That dude is wrong. This is hugely false. Different loudspeakers/subwoofers may have different motor/coil constructions resulting in different frequency responses that you can hear. What he's implying is that if you connected a 250W sub with the same impedance to your amp, that the signal coming out of the amp would somehow be different. The only shred of truth to this is the motor construction of the sub itself (different construction can handle different power levels), but it does not follow, whatsoever, that the amp's signal output is somehow effected by the maximum power handling of the load you're connecting to it.

Anywho, that's really besides the point. All I'm saying is don't worry about that. Report back to us after you find out what the flashing light is.

 

To me it sounds like he is implying that distortion will blow a sub. Which is false. I'm pretty sure they still repair the slash v1 amps. It would be worth it IMO, those amps are really pretty nice.

 

Im sure they would repair it, but i don't know if the price would be worth it when I could get a used 250/1 for less than 100 bucks or a 500/1 used for less than 200. Ill try to see what they say, ill give them a call today. Thanks guys!

 

Well... it started working again.

I email JL Audio (which emails back within minutes) saying that it was extremely unusual for my amp to go into thermal. They recommended me taking it out of the car and unpower it for at least 30 minutes - they said it should reset the thermal protection circuit.

After I reinstalled it, it thermal-ed again and I thought I was SOL. An hour later, when I actually took it for a drive, noticed that I had my bass again. And it's worked for the rest of the day. No idea what happened, but it seemed that the protection circuit resetting worked. Sorry and thanks for your help guys!