What is this amp for is it for highs ad bass

you need to get a universial bass control knod with rca in and and rca out to amp input

The amp is clipping the signal. This could be from the input being too high. The impedance being too low or the finals are damaged.

Bass boost simply adds DB or gain to the bass signal. Some like it, some dont.
The frequency knob is the Low Pass Filter (LPF) that cuts off the amp output above
the set frequency. A bass system usually cuts off below 400 HZ and more often 200HZ.
A good, rattle your car bass note is in the 25-80HZ range or lower but most amps and audio
input devices cant attain a good low note with clarity.
"Low-pass filter allows only frequencies below the crossover point to be amplified. A high-pass filter allows only frequencies above the crossover point to be amplified - useful for keeping low bass away from small speakers, so they can play more efficiently."
Checkout Crutchfields Glossary of Car Amps.
http://www.crutchfield.com/S-LPyoWWgD5qN/learn/learningcenter/car/amplifiers_glossary.html

If none of the inputs work, then you may have lost part of the power supply. DO NOT go into this amp under any circumstances !!!!...there is enough voltage in here to kill you crispy !! I would strongly recommend that you take it to a respected repair shop that specializes in guitar amps. Possibly visit the ampeg website for an authorized repair center. It might cost a few bucks, but the Ampeg is highly sought after by musicians everywhere !!!....thanks... Rob

• Class-D Monoblock Amplifier
• Bass Boost Level and Frequency Remote Included
• Variable Low-Pass Filter: 50 - 200 Hz (24 dB/Oct.)
• Variable Input Sensitivity: 200mV - 5V
• Phase Shift: 0° / 180°
• Variable Infrasonic (Subsonic) Filter: 0/15Hz/25Hz (18 dB/Oct.)
• High- and Low-Level Inputs
• 1 Ohm Stable
• RMS Power Output:
• 500 watts x 1 chan. @ 4 ohms
• 900 watts x 1 chan. @ 2 ohm
• Preamp Outputs: 1 Pair
• Bass Boost: 0 - 18 dB @ 40 - 100 Hz (Variable)
• Dimensions: 15" L x 11-5/16" W x 2-3/8" H

i can tell you right now base on the vehicle you have a bad system hook wosrt if you are using factory head unit

took at ur rca on the amp they may going

2 subs and 1 amp

Hook the speakers in series to decrease your chances of blowing the amp and/or speakers themselves. And at high volumes make sure that the bass control is set for flat response.

Sometimes an amplifier's preamp can't handle certain signals/frequencies at a high gain, so they cut out. Bass guitars are especially prone to giving such a strong signal.
I bought an older, nonworking bass amp recently and fixed it just to find it had the same problem. Best solution is to put a low ohm resistor at the amps input, but if you turn your guitar down to half volume it'll have the same effect: should prevent it from cutting out.