SUB output levels randomly decreased

[andrewibk 10+ year member]

Here's my set up:

Pioneer AVH 4500

JL Slash 500/1

10'' W6.V3 sealed

Was on a road trip listening to music, I normally have my SUB level at around -14 to -12. Didn't notice right away since the music wasn't turned up too much but my SUB output level significantly decreased a few hours into the drive. At first I thought the amp was in protection mode or something. I increased the SUB level on my HU to -2 maybe 0 and had the same amount of bass output I normally get at -14 to -12. I don't want to risk sending a clipped signal or something so I haven't turned it up too much since. Any ideas?

Thanks

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[Jepalan]

That amp has a "soft" protection mode. Might be losing a voice coil and overloading it, or it is false triggering when hot. Here is wording from the manual...

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If you connect a load lower than 1.5Ω nominal to the 500/1, the amplifier protection circuitr y activates a “safe” mode which reduces amplifier power to protect the circuitry from failure (the yellow LED on the top of the amplifier will light to indicate that this has happened).

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Is the yellow light coming on?

 

[andrewibk 10+ year member]

Thanks for the reply.

No, the yellow light is not on, it's still green.

The SQ sounds normal or atleast very close to normal... not distorting or anything... (this is at SUB level -2) (normal listening levels -14 to about -12)

 

[Jepalan]

Not sure. 10 clicks is a lot of volume difference. Maybe try these:

1) Measure ohms of each voice coil to make sure one isn't burning out. Each VC should measure around 1.7 ohms

2) Check and/or or replace RCA cables between HU and amp

3) Check voltage at sub amp with voltmeter to see if DC volts is dropping.

4) Check wiring from amp to sub

 

[Side Show 10+ year member]

check settings on amp also, I have found on some long trips, my setting on my amps all vibrate down to 0. (due to shithouse roads)