Well just finshed buliding a new sub box for the old lady's new car. Yesterday we went and picked out some subs and I already had a new amp so I said I'll just let her use it to power the subs. But looks like the amp I have is not enought to power the subs properly before I go and exchange amps and shell out the extra cash I like to make sure. Here what I'm looking at..

400 Watt 2-Channel Power Amplifier with Built-In Crossover



Features

PWM Regulated MOSFET Power Supply

Bridgeable 1/2/3 Channel Capability

Balanced Isolator Input Circuit

Oversized Screw-Type Power/Ground Terminals

Screw-Type Speaker Terminals

RCA Inputs

Hi-Volt Input Level Control (200mV-6.5V)

Speaker Level Inputs

Selectable Crossover: 80Hz, -12dB/oct. (LPF)

Specifications

Continuous Power: 75Wx2 (4 Ohms), 100Wx2
(2 Ohms), 200Wx1 (4 Ohms)

Peak Music Power: 400 Watts

Frequency Response: 10Hz - 50kHz (0,-1dB)

Total Harmonic Distortion: 0.008% (1kHz, 4 Ohms)

Signal-to-Noise Ratio: 100dB (IHF-A
Weighted, at 1Khz)

Dimensions: 10-7/16" x 1-15/16" x 9-5/16"

Infinity Reference 1020w 10" Woofer
Sensitivity: 90db
Power handling: 250w RMS
Requency Response: 22~800Hz
Nominal Impedance: 4ohms

Looks like I don't have enough amp to hold those subs, but what if I bridge the amp and run in the subs Parallel.

you didnt mention the brand name of the amp, but i am assuming its a low-level brand (jensen, optimus, pyramid, legacy, etc..). if that is the case, you run into problems not by underpowering the subs (assuming its clean power), but my causing the amp to distort, or "clip". this will not really hurt anything (others will disagree with me on this point, if youd like i can explain in more detail), but it will sound terrible. if its an amp of better quiality, you might as well hook everything up to see how it sounds. seeing as how you have two 4ohm subs, you would not want to run the amp bridged, as whis would stress the amp and produce more heat than it could handle. youre only option is to run one sub off of the left channel and one off of the right.

if you decide that you need a bit more "umph" out of the subs, make sure you get either a 2channel (or mono) amp that is capable of holding a 2ohm bridged load or a 4 channel amp that is stable for bridgin 2 channels to each sub (any 4-channel amp can do this).

edit: forgot to give you a tip....if at all possible run the same signal on the left and right channels. on some headunits/eqs it will give you the option to do this via a switch (or electronic setting) giving you the option of either "stereo" or "mono". run it in mono. this will reduce cancellation between the subs, and since its almost impossible to distinguish left/right stereo bass, you might as well do it. if you can do this, youll be pleasently surprised by the difference it makes.

opps sorry Its a Pioneer GM-X572 2 channel bridgeable amp

ahhh....so its not a crappy amp. i would try hooking it up to the subs first just to see how it sounds before getting another amp.

SPL is right. Hook it up, see how it sounds. She might be content with just a little bump, if she needs more then go bigger. The best way to avoid spending anymore money is to hook it up when she is somewhere, then once you're done say "Hey honey, I got it done and it sounds real good, come listen." That way she goes in thinking positive...:thumbsup. Good luck man.

Thanks everyone ..... I have one more question ... She wants to keep the factory headunit and cd player. While I was getting grocerys this morning I looked at wal-marts car audio stuff and they have a rca line converter has anyone had any experince with these all the system I've installed have been with new after market head units. What all do I need to do to use the factory headunit.

the amp already has an adapter built in, or at least that one of the things you mentioned when describing it. thres no need to buy another one, just tap the signal off of the rear speakers and run it to the speaker wire inputs on the amp. if you decide to get a different amp that does not include this feature youll need to buy a line level coverter.

What do I use for the remote wire to turn the amp on? sorry I've never hooked one up to a factory head unit.

the easiests way would be to tap the acc power off of the stock headunit. this would not be the same thing as a remote turn on (the amp would be on as long as the car was on, even if the headunit was turned off), but theres no problem in that.

go to www.installdr.com to get the factory wire colors. put a t-tap on the wire that only recieves power when the car is in the "acc" position.

well got everything hooked up but, I set off the anti-theft device in the head unit. I tried some codes but they didn't work. I'm thinking that I'm really screwed. Am I???? What should I do now? The owners manual says I must take it to the dealer which is 50 miles away. How much is this going to cost me? or is there anyway around it? Thanks

what kind of car is it?

you could probably call the dealership and explain the situation. if theyre nice they might tell you how to re-set it over the phone. otherwise im sure you could find out how on the net somwhere.

Well thanks for all the help. Yep I searched a few sites and found out that I would need to get the code from the dealer but, I went and got a new head unit. My old lady found a nice head unit that plays mp3's so we just went with that beside I figured that the stock head unit wouldn't do the whole system any justice and the amp seems to power the subs great but I haven't pushed them hard yet just breaking in the new subs right now.

thanks, im glad to help. :thumbsup

let us know if you have anymore problems or questions. :D

LOL Well got one more question/problem I can't get the new head unit installed in the car right. its either tilted back or forward... everywhich way you can imagine. I bought a install kit but this one isn't like the one for the 1st gen car.

you havnt mentioned what car this is for, so ill refrain from giving any instructions until in know that. :P

you mentioned somthing about it not being the same as a 1st gen., so i assume its an eclipse, but i could be wrong.

Oh I'm sorry its a 98 eclipse

ok, im a bit rusty at this considering my headunit and all the surrounding components havnt been stock for over two years, but here goes...


1) disconnect the negative battery terminal (this isnt really necissary, but is a good precausion)

2) remove the side panels that run from the center console to the firewall by popping out the caps in the center of them and removing the screw. it helps to bring the seats all the way back to do this.

3) pop off the radio/HVAC controls cover (the black piece).

3) you will see four screws holding the factory headunit and bracket in plase. remoe these, disconnect the harnesses, and remove the wntire assembly. seperate the brackets from the headunit, making sure to notice how it alligns with the bracket.

4) using some short screws (should be supplied with the new headunit), attach the stock brackets to the aftermarket headunit.

at this piont youll need to reverse the steps and put everything back together. im not sure how the install kit fits into all of this, but i hope that gives you some ideas. im pretty sure that if you have the "pocket" underneath the radio there is no need for an install kit, it fits right into place. if you have the double-din headunit stock, you may need one. agian i muct mention that its been a long time since i had anything near stock in that area, so i could be totally off. you might want to start a new thread on this topic to get more replies.

nest of luck ;)