JL 300/2 "Low ohm" light: What does this mean?

[FSUNole17 10+ year member]

I bought my JL 300/2 about 4 years ago and it has been working flawlessly for a long time. Not too long ago, my speakers started sounding awful and I couldn't figure out why. I started with the amp and noticed that the "low ohm" light was coming on. What could this be? Do these amps have this common problem? I hooked up an old school RF Power 350 amp to the speakers and they sounded great, hooked the JL amp back up and they sounded awful. I don't know if the amp is broken or not, but that low ohm light comes on and I am wondering if there is something that I could do to fix it without buying another amp. Any input would be appreciated. Thansk!

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[FSUNole17 10+ year member]

Also, the system I am running is a Pioneer Premier 860 into the JL 300/2 that is running some Boston Acoustic Pro series 6.5" components.

 

[NightDrifter05 10+ year member]

If you connect a load higher than 4Ω nominal per channel in stereo mode (or 8Ω in bridged mode), power will drop by half with every doubling of impedance above 4Ω stereo / 8Ω mono. If you connect a load lower than 1.5Ω nominal per channel in stereo mode (or 3Ω in bridged mode, the amplifier protection circuitry activates a “safe” mode which reduces amplifier power to protect the circuitry from failure (the yellow “Low Ω” LED lights to indicate that this has happened). See page 10 for details.

http://mobile.jlaudio.com/products_amps.php?amp_id=437

Click on the manual.

 

[FSUNole17 10+ year member]

Drifter, for over 3 years this was not a problem and then all of a sudden it started happening, so I know that isn't it. I have been running the same 3 ohm Boston Pros the whole time as well. Anyone else have any suggestions? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[undeadxsunshine 10+ year member]

Sounds like your amp is broken somehow.

 

[NightDrifter05 10+ year member]

I don't know what caused it but all you asked is what the low ohm light mean's and that's exactly what it mean's. Check the ohm load your amp is getting. Something with the speakers might have went bad and it might be altering the ohm load. The reason it sound's awful on the JL is because of the Low Ohm Load Protection which it says put's it in a safe mode to limit the power they receive. That Rockford you tried doesn't do that so that is why they sounded fine. All I really know to tell you is to pull out the DMM and check the ohm load on the amp. On another forum someone had a similar problem and someone from JL told him to power the amp up without ANY speakers attached. If the low ohm light still come's on without speakers attached then it's a problem with the amp.

 

[FSUNole17 10+ year member]

10-4, gotcha. Thanks!

 

[AlterEgo99 5,000+ posts]

I don't know what caused it but all you asked is what the low ohm light mean's and that's exactly what it mean's. Check the ohm load your amp is getting. Something with the speakers might have went bad and it might be altering the ohm load. The reason it sound's awful on the JL is because of the Low Ohm Load Protection which it says put's it in a safe mode to limit the power they receive. That Rockford you tried doesn't do that so that is why they sounded fine. All I really know to tell you is to pull out the DMM and check the ohm load on the amp. On another forum someone had a similar problem and someone from JL told him to power the amp up without ANY speakers attached. If the low ohm light still come's on without speakers attached then it's a problem with the amp.

What he said! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[JDBoogie 10+ year member]

check your x-overs also. x-overs can cause the same problem.

 

[bernser1er 10+ year member]

i had this same problem thats why i dont like jl amps

 

[Mass Car Audio 10+ year member]

What impedance is the amp seeing per channel........ Sure you can run a amplifier below the minium impedance but over time it will kill it.