amp cutting out

alright heres the deal.......i just got my rockford amp and HE2.....i have the 1500W 501S......now i bridged my amp to the sub and wired my sub up like this

sorry i dun know what its called.......

so does anyone have any ideas why it would start cuttin out......i had been usin it fine but only for short amounts of time (15-20minutes) for tuning......and today i was usin it for about 45 minutes when i was driving.......all i could think of would be that its overheating.....but its mounted on the back of a box in my trunk with plenty of airspace to cool......so i dunno.....

oh also......everytime it begins to cut out i would turn off my HU for a minute or two, then turn it back, and it would be fine for about another 5 minutes b4 it happened again......

alright sorry its so long......thanks in advance

 The 501's ratings are below
•  125 watts RMS x 2 at 4 ohms
•  250 watts RMS x 2 at 2 ohms
•  500 watts RMS x 1 at 4 ohms in bridged mode
You are running your sub bridged in parallel for a 1X2 Ohm load. Your amp is cutting out because it cannot support a 2 ohm load bridged, the lowest it will go is 4 ohms bridged. The only way to hook it up is to wire each voice coil to its own channel for 125 watts X 2 @ 4 ohms. I would also suggest you get a Y and split one of your input channels so you have a mono input signal if you wire it 125X2. That amp is not a very good match for your sub; you may want to consider a different amp

Your amp is going into protection for multiple reasons

(1) the amp is not designed to operate at a 2ohm mono load. You have parallel wired the subs to a 2 ohm mono load.

(2) you may have a really crappy ground.

(3) you have a high resistance on the ground

(4) you have the gain / bass boost on the amp too high.

Now while your amp will probably play all day wired the way it is at lower volume levels, at higher volume levels the amplifier produces excessive heat which sends the amp into thermal protection (don't want to melt the amp right).

Now I don't know who sold you your equipment, but I for one would head right back and get a different amp or a different sub, you were sold good equipment, it just was not matched together correctly. To keep the sub, have a look at the Rockford Power 351M. It is designed and engineered to run continuously at 2ohm mono with a MINIMUM of 350 watts rms, you sub need 250-400 rms, a much better match.

You can wire it to one channel, or you can get a Y and split the input signal which will give you a mono signal to both channels. Either way you hook it up you will get the same power. And as long as you have a mono signal, each voice coil will get the same signal so it will be safe to wire your sub to 2 channels.

so if i leave the sub wiring how it is now, and put it on one channel then i should be alright right?

i mean i could always go get a new amp and reconstruct everything i got but that just means more $$$......and im tryin to get a new car, instead of new car stereo

You’re correct; the easiest thing to do with the current setup is to bridge your sub to 1 of the 2 channels which will give you 250 watts rms total. However if you plan on using that as your permanent setup I would suggest you either return or sell that amp for a better match.

dammit.......the HE2 is rated 400 W RMS......with that I'd be underpowering my sub.......

man i'm leery on returning my amp, cuz i work for best buy (where i got it)......and i had a Kenwood that blew, then i got my 1500 w....but they gave me the 4 channel instead of the 2......now i have the two....and this happens.....they're gonna get pissed at me......

anyone got any way i could use this amp to power my sub w/o havin to return or purchase anything and w/o damaging anything???

115 it is in southern cali.......

yea bberman said to run it off one channel but that leaves me with a 250 w load.......which is underpowering......or was there somethin else i overlooked?

I think you're okay with the components you have.  Even though your subwoofer is rated for 400WRMS, that doesn't mean you have to supply it with 400 Watts.  250 Watts is an appropriate amount of power for that speaker.  It's a bummer that you're not getting the full 500 Watts out of that amp that you would get bridging it into a 4-ohm mono load, but it's the best you're going to be able to do without swapping out some of your gear.

Now for the tricky part.  If you run the amp in stereo mode, and put one channel into each voice coil, you have to make *certain* that both voice coils are receiving exactly the same signal.  If you don't, then one amp channel might be pulling the voice coil one way, and the other channel might try to pull it the other way, causing a loss of power or speaker damage.  Someone else mentioned using a Y-splitter to make sure both inputs on the amp get the same signal, but you also have to match the two gain controls exactly.  Here's how:

Get a test CD that has a bass-frequency test tone, like 40 Hz.  Connect up one channel of the amp to the sub, play the test tone fairly loudly, set your gain for that channel and measure the AC voltage across the speaker terminals.  Write that number down and disconnect the speaker.  Now, connect the other amp channel to the other voice coil, play the same test tone at the same volume, and adjust the gain control on the second channel until the voltage matches what you had before with the other channel.  Now you can reconnect all the wires, and you know that your gains are matched so that when both channels get an identical input, they'll produce an identical output.

Scott Gardner

 but you also have to match the two gain controls exactly.  Here's how:

   Only 1 gain on a 2 channel amp isnt there? Good info though

You're absolutely right - there's only one gain control on a stereo amp.  I was confusing this with another install that had a four-channel amp bridged into two channels, each driving its own voice coil.

Thanks for catching this.

Scott Gardner