Help me figure out why amp is going to protect mode....

[GhettoBlaster]

I have a RF R500-1 amp powering two RF P2D210 subs (500W RMS amp powering 2-300W subs). Subs are DVC and are wired in parallel at 4 ohm's each for 2 ohm's total. Amp is supposed to be 2 ohm stable. After a while of listening rap music or any music with lots of bass, amp goes into protect mode and is hot enough I can only put my hand on it for a couple seconds. I got my multimeter out this morning. With the car running and playing a song with lots of bass at semi loud level, the volts at the amp never drop below 14.25V so I don't think I'm in a low volt/hi current condition. I tried to test the ohms at the amp and the meter fluctuates between 0 and 6 ohms. Don't know if I'm testing the ohms wrong or the meter isn't working properly, although it does seem to be testing the volts just fine.

Any suggestions....please help!!!!!

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[LosIsATool 5,000+ posts]

what are your HU settings and amp settings? Bass, Gain, Bass boost?

 

[>>SQL<< 10+ year member]

I think you have it wired to 1 ohm

If those subs are Dual 4 ohm coils then your final load will be either 1 ohm or 4 ohms

It works like this each coil is 4 ohms, both coils tied together on each speaker makes it 2 ohms, then both speakers tied together gives you 1 ohm

To use your DMM to check you ohm load you should disconnect the speaker wires from the amp then touch the dmm to the wires.

 

[GhettoBlaster]

what are your HU settings and amp settings? Bass, Gain, Bass boost?

HU bass is flat. I have a HU amp/sub out volume that is set on 5 out of 8. My amp gain is about half of max and bass boost is 1/4 to 1/2 of max.

 

[GhettoBlaster]

Thanks on the "how to" and I will retest, but I'm quite certain I've got them wired up correctly. I don't do much car audio stuff, but I've taken a years worth of circuits classes in college. Car audio = DC= easy......AC circuits......not so easy.

I came up with the wiring myself and then consulted the sub owners guide and it agreed with what I came up with. Each speaker has two voice coils that are two ohms a piece. The voice coils are wired in series so each speaker is a 4 ohm load. Then the speakers are wired in parallel for a 2 ohm load on the amp.

 

[>>SQL<< 10+ year member]

Thanks on the "how to" and I will retest, but I'm quite certain I've got them wired up correctly.
I came up with the wiring myself and then consulted the sub owners guide and it agreed with what I came up with. Each speaker has two voice coils that are two ohms a piece. The voice coils are wired in series so each speaker is a 4 ohm load. Then the speakers are wired in parallel for a 2 ohm load on the amp.

yes if those speakers are Dual 2 ohm then the way you described is correct.

however a quick check with the DMM would be best.

 

[GhettoBlaster]

yes if those speakers are Dual 2 ohm then the way you described is correct.however a quick check with the DMM would be best.

I've tested and I am getting .9 ohm at the amp. I've checked the wiring and it is correct. This is news isn't entirely bad though. If I wire my speakers in series I'm guessing I should get ~4 ohm which will still give me enough power, my amp will run a lil cooler and my sound quality will be a lil better. I kinda wished I bought the dual 4 ohm coils so I could run with a 4 ohm resistance at my amp anyway.

Now, since I'm running my speakers in series....will I need a larger gauge speaker wire???

 

[Jd377 10+ year member]

Is your voltage good enough at the amp?

 

[GhettoBlaster]

JD377...With car running and music playing at semi loud levels, voltage never went below 14.25

I think you have it wired to 1 ohmIf those subs are Dual 4 ohm coils then your final load will be either 1 ohm or 4 ohms

It works like this each coil is 4 ohms, both coils tied together on each speaker makes it 2 ohms, then both speakers tied together gives you 1 ohm

To use your DMM to check you ohm load you should disconnect the speaker wires from the amp then touch the dmm to the wires.

Thanks for the help with the meter. Got 'em wired in series and have 3.5 ohms at the amp now. Pushed 'em about as hard as I did before when amp went into protect and didn't have any problems and the amp was a lot cooler. Then a couple hours later I pushed 'em real hard (harder than I would for normal listening purposes) for twice as long as they were running. Amp got hot but nothing shut off. Seems to be working like it should now.

 

[akheathen Premium Member]

something is not right....... you should be reading 8ohms, by your description (2+2+2+2=8) also, it should be just fine series-paralleled to 2ohms. check the battery in the meter, and re-test the speakers. also helps to check the ohms of a known good speaker, like a house speaker... individual coils would be best at this point. it is also possible that you are simply clipping it hard, and the protection mode, is just doing it's job and protecting from burning stuff up. btw- amps are ac, lol....just saying