Amp going into protect mode at high volume...why?

[jeryan]

Ok, so I was driving down the road and all of a sudden the amp went into protect mode. Mind you I have had this system for about 10 years now. It goes into protect mode at high volumes but once I lower the volume the amp is able to come out of protect mode and work. If I have only 1 sub running then I can go louder, but not by much. When the subs are not plugged in there is no issue. The ground is secure, the fuses are good and everything is well connected. I am not sure what the issue could be nor how to fix it. I am running an Infinity Reference 1600a mono amp powering 2 Infinity Reference 1260w subs.

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[Smurfy76]

Sounds like possibly the amp is going out.

 

[1aespinoza 10+ year member]

The ground is secure, the fuses are good and everything is well connected.

What awg and fusing are you using. Sounds like it might be time to refresh your connections. High demand with limited voltage input may be causing amp to protect itself.

 

[audiobaun 5,000+ posts]

Time to check each sub woofer individually to see if within Ohm limitations with a DMM, and check all connections for corrosion. May not be a bad Idea to replace existing fuses as they get weak over time and freshen up all connections with fresh clean exposed wire connections. Thats where Id start. Subs and refresh all fuses and wiring connections.

 

[audiobaun 5,000+ posts]

You may have a bad coil on one of the subs throwing the amp into protect with a non stable ohm load

 

[Lasherž]

Ok, so I was driving down the road and all of a sudden the amp went into protect mode. Mind you I have had this system for about 10 years now. It goes into protect mode at high volumes but once I lower the volume the amp is able to come out of protect mode and work. If I have only 1 sub running then I can go louder, but not by much. When the subs are not plugged in there is no issue. The ground is secure, the fuses are good and everything is well connected. I am not sure what the issue could be nor how to fix it. I am running an Infinity Reference 1600a mono amp powering 2 Infinity Reference 1260w subs.

Grounds are notorious for failing even when they're tight and look secure, especially after 10 years. I'd take that bolt off and resand the surface and the connector, then tighten it back up snug. Maybe also check the car's ground connection off the battery for good measure. If that doesn't fix your issue then get out the multimeter and per 1aespinoza/audiobaun's suggestions, check the resistance at the enclosure terminals. It should be anywhere from 2/3 to 3/4 of the expected impedance (I don't know how your subs are wired). If it's lower you likely have a bad coil or a strand from one terminal has snuck over to the other terminal (either at the amp or at/inside the enclosure). If it's higher you either have a bad coil or a connection is loose inside the box. He also made a good suggestion to refresh the fuse connections, I might redo the battery connection as well and if the copper strands are largely oxidized at the amp connection (+ or ground) cut them off and strip the wire for fresh strands.