Stock Radio Distorts When Bass Hits

[gm2500main]

Hi. I just installed a new amp and sub in my 2002 Toyota Tacoma. All was well, until I realized that whenever the bass hits, it doesn't hit as hard as it could, and the audio on the stock radio speakers distorts. At night I can tell that the dash lights dim also when the bass hits. I have heard capacitors are crap, and adding an additional battery doesn't make sense to me either. I think I need a higher amperage alternator? Any thoughts would be helpful.



Setup:
Pioneer TS-SWX310 12" Enclosed Subwoofer Truck Box with bridged Lanzar HTG237 Heritage 1000 Watt 2-Channel Amplifier

Amp is connected through wire taps that go to rear channel outputs from stock radio which there are no rear speakers besides the sub.

 

[AKHeathen]

the specs of the amp were fuzzy and unclear, giving no bridged rms, but given the single 25a fuse, it shouldn't be more than 250rms. this should not dim your lights, nor stereo distortion. how do you have it wired? should have 8, or maybe 10awg power cable run from the battery with an inline fuse near the battery. should also have a ground cable the same size as the power cable, grounded to the body real good. i'm not sure about your model year, but just about all the toyotas i've seen until recently, have a poor battery-to-body ground. make sure that is good as well. i do not see a high-level input either, nor an automatic turn-on feature. i would check the pin-out of the head-unit for an accessory/remote turn-on output and run from that to the remote of the amp. also, buy a "LOC" (Line Out Converter). they can be had for $10 or less. then you can use those speaker wires properly to feed an rca signal to the amp. something you are doing sounds like it is damaging, or is sure to damage the factory head unit. also, that is one single sub, or at least the final load is 4ohms, right? generally, no alternator or second battery upgrade is needed for 1200w rms or less. at 5-600w rms+ i would suggest a good performance battery (don't get an optima, as they have a horrible long-term life and durability) if you have the money to step into an agm, i recommend an x2power. however, all you should need is a good condition normal lead acid.

 

[Perry Babin]

If you are trying to get more out of the sub, you may have set the bass higher than normal on the head unit which would cause the internal amplifier (in the head unit) to draw more current when the bass hits which could cause the lights to dim.

Try setting the bass lower (flat) on the head unit. Set the subsonic to 0 on the amp. Set the bass boost to 12dB. Set the LPF to ON. Set the crossover to about 100Hz. Set the gains as high as they need to be to get the output that you want.