Why does my amp cut off my sub at high volume?

[alexdbest2000 10+ year member]

this is my setup:

Kenwood bt852hd (2.5V pre-outs)

Alpine MRV-M500 amp (500 rms at 2 ohm)

Sundown SA-12 D4 sub

1 gauge wiring

To adjust gains I:

1) unplugged all speakers and sub

2) set all eq, bass boost, gain etc to 0

3) set LP filter to 80

4) played an 50 HZ track on repeat

5) connected DMM to sub +/- terminal on amp

5) turned gain up to meet voltage requirement (31.6)

6) had to turn gain almost to max...

Every time the sub hits hard at around 3/4 the volume the amp turns the sub off, while the amp stays on. The sub will only work after i shut the car off and then turn it back on, the amp is brand new. I dont think its a grounding problem, i drilled a hole in the chassis and grinded away any paint. Is it normal for the gain to be set that high? Is the amp going into protect mode? Why is it doing this? Am i missing something with tuning the amp?

this is where my gain is

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[CSCStang]

When you set the gain, what volume did you have it at? Should be at 3/4 when setting. How is your sub wired? Should be parallel for a 2 ohm load.

 

[alexdbest2000 10+ year member]

When you set the gain, what volume did you have it at? Should be at 3/4 when setting. How is your sub wired? Should be parallel for a 2 ohm load.

yep i had it at 3/4, the sub is wired it like this for 2 ohms:

 

[MrFoca]

Sounds like the amp is clipping out. But why it does not come back on till you turn the car off is odd.

 

[Sizzlechest]

My factory radio in my car would cut off audio when it clipped, and not come back on until I power off and then power on again.

 

[xxrcm619xx]

May not help, since it seems to be setup correctly, but i would double check wiring from the inside of your sub enclosure to the amp it self, maybe even the wire to the HU and Batt. If all checks out good, maybe your amp, may to be looked at..?