snosleder080

OK, this is probably a dumb question but I am going to throw it out there. I have a old set of mtx 10" subs with a 1200w 4 channel legacy amp out of previous vehicle that I would like to salvage in my 09 f150 screw to offset the lack of bass from factory.

The plan is I would like to use just one of the subs (assuming like 400w max MTX 10") in a custom box I will build to fit under the small rear fold up seat. Nothing fancy, I am not trying to blow the windows out by any means. I will be keeping the stock radio, and I will just get the rca taps to hook into the factory radio. I guess my question is will the amp work even though it is way overkill? If it will in fact work, how do i hook it up as not to blow the sub sky high? Will just keeping the gain turned way down work? Hook it up unbridged I assume? How many ohms? That kind of stuff. Here are the specs on the amp:
Legacy - 4 Channel 1200 Watt Bridgable MOSFET Amplifier

• Tri-Way Output Configuration: 4 x 300 Watts Output 2 x 600 Watts Bridged Output 2 x 300 Watts Front + 1 x 600 Watts Rear
• Polished Chrome Finish w/Plexiglass Panel
• Integrated Heatsink for Efficient Heat Dissipation
• Remote Control Bass Booster (0~12dB @ 60Hz)
• Fully Adjustable Electronic Crossover Network
• Soft turn On/Off Circuit
• 2 Ohm Stereo Stable
• Bridgeable into 4 Ohms
• Dual MOSFET PWM Power Supplies
• Variable Gain Control
• Remote Turn On/Off
• Hi/Lo Level Inputs
• Power On LED Indicator
• LED Protection Indicator
• S/N Ratio: >90dB
• THD: <0.04%
• Frequency Response: 10Hz-30k Hz
• Thermal, Overload & Short Circuit Protection
• Dimensions: 2''H x 11''W x 14.2''L

http://www.qualitycaraudio.com/store...dproduct=17415

Any advice would be awsome! Thanks

Windup

Assuming the MTX subwoofer is a 4 ohm single voice coil (svc) that is rated to handle 400 watts rms.

Giving it the 600watts bridged that the amp puts out is over powering it. That MTX should be able to handle more that its rated for and it's unlikely that you'll get the listed watts out of that legacy. ( it was tested at higher volts, distortion that you'll get / want)

I think you were already been giving each subwoofer 600 watts if you had one bridged on the front and one bridged on the rear.

Wyo11Scab

iTrader: (1)

First use an FRD24 so you won't have to tap any speakers. It also provides the amp turn on wire. Then get a sub that can handle the power. Then tune it using your gain. Run the amp in bridged mode. It is 2 ohm stable so 2-4 would be ok.

snosleder080

I plan to use the frd24. If I use only one channel unbridged will that knock down the power of the amp to 300 (as its shown 4 x 300)? I know I'm not using the full potential of things but the point is to use what I have already.

PondJumper

Yes it will be fine. People(myself included) are often confused by the 'gain' **** on an amp. There is a sweet spot for every amp/head unit combo. Anything above that=distortion (heat), anything below that is ok as long as you don't try to demand more from your speakers than they have the power to do.

Adjusting the gain only adjusts the amount of voltage amplification that is being done to the voltage that your head unit is already supplying. If your talking about a factory head unit, it's best to keep the gain turned down quite a bit as there will be less (already existing) voltage for the amp to work with.

By keeping the gain **** at a low setting, you won't be trying to 'over amplify' what you have to work with. I hope this makes a lick of sense. It seemed to in my head. Long story short, you'll be fine.

snosleder080

Thank you! Exactly the answer I was looking for.