New issue :/

[CSCStang]

I'm running an mrp f300 (4ch, 50w rms) to sps 517's ( 75w rms) in my rear deck and the sps 610c in the door. When I have it cranked, the rear speakers are cutting out and I noticed the amp is a little warm. When the amp cools, the rear come back on. The front never cut out. I'm at 1/2 gain and I don't push my speakers to distortion. Would love some feedback. Thanks. Anyone?

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[CSCStang]

Any thoughts?

 

[bbeljefe]

How do you know you don't push your speakers to distortion?

Half gain means nothing and if you're running a 4 volt preamp signal you are absolutely running your speakers to distortion. How did you go about setting the gain?

 

[CSCStang]

It's a 2 volt pre out. I set it by gain down, volume up to dist, then down one and the gain up to clear level. It's there a better way? Do the rear speakers just draw too much at 75w?

 

[VWBobby 10+ year member]

How are you testing for distortion? By ear, DD1, or O-scope? If you are setting by ear, you are sending distortion to your amp or speakers long before you can hear it.

 

[CSCStang]

Yeah by ear. What would be a better, but not so expensive way? Is it a matter of just turning the gain down more?

 

[shizzzon 10+ year member]

What is the ohm value of the rear speakers?

Also, what size and how long speaker wire are you using?

 

[CSCStang]

4 ohm. Speaker wire is 1ft. On the right and 4ft. On the left. The front are about 11ft, but I don't have any problems with the front cutting out. I'm using 16 ga. Wire.

 

[CrossoverOre 10+ year member]

make sure the speakers are not shorting out and the wires are not pinching somewhere.

 

[VWBobby 10+ year member]

Yeah by ear. What would be a better, but not so expensive way? Is it a matter of just turning the gain down more?

Least expensive but accurate way is with a Nano Oscilloscope Arm DSO Nano Pocket Sized Digital Oscilloscope | eBay ...about $70. An SMD DD1 runs around $100.

You could just turn down the gain and it might help. If you are running 4 ohm speakers, 1 per channel, you shouldn't have any problems with it cutting out around 1/4 gain, especially with 2V preamp outs on your HU. Again, it is best to adjust your gain with an oscilloscope or DD1 rather than tuning by ear.

Good tip on checking for shorts in your speakers or wiring. Check everything with an ohm meter and visually inspect your wires for tears.

 

[CSCStang]

Will do. Thanks for all the input. Much appreciated.