hooking up an amp

[szabo016]

So i have a 96 eclipse and the person i bought it from already had a stereo put in. The stereo is a Alpine CDM-7874. When I bought the car I replaced the factory speakers with Alpine 6x9 SPS-69C2 in the back and the front has the matching 6 1/2's (SPS-17C2). I just got an amp from a friend and I went and had it tested to make sure it worked. I am trying to pull out the factory amp and replace it with this kenwood KAC644. First of all I can not tell any difference when the factory amp is disconected and when it is connected. So to hook this amp up I used the power and ground that my stereo was using and just made a Y connection. I also tested so I know for sure it was getting power. Then I cut the wire going from the back of the stereo that was for the back right speaker (I was only trying to hook up one speaker to test it). Then I bacically had the two wires still connected but taking a detour through the amp. It will play when the two wires stay connected but when I put them throuugh the amp it is shorting out and nothing happens. There is also two pairs of RCA connectors for the front and the back speakers on both the stereo and the amp if. Those were also plugged in. And there is a DIN connector on the back of the stereo going to the stock amp. Do I need to do anything with that because the kenwood amp does not have a DIN connector.... But the way when I play it with the stock amp the amp fuse under the dash always blows. Can someone give me any advice on what to do to make it work?
PS. The amp is 4x40 watt
and the stereo has a buit in amplifier of 4x50W/20W RMS

[SilvrEclipse]

Wow you have a lot of work to do.

1) you cant use the power and ground from your stereo to power the amp. The amp will get staved for power and may blown your radio fuses. Run a new power wire from the battery.

2) the only way to hook up door speakers to an amp is to run your RCAs from your stereo to the amp. Then run wires from the outputs on the amp directly to the speakers. Your not using the speaker wires from the stereo.

[szabo016]

Do you think that size of amp will even make a difference??? i hate to go through all this trouble and have it not any better

[SilvrEclipse]

It may not be much louder but the sound quality will be better. Built in amps tend to not be as nice and start to distort at high volumes.

[szabo016]

well it isn't even running of of the factory amp. There is something messed up with it and it always blows out the fuse. So really I have been using no amp at all other than the amplifier that is in the stereo. So do you think this kenwood amp that I want to put in will still make a difference?

[SilvrEclipse]

When you change to an aftermarket cd player you dont use the factory amp anyways. You dont use both the stereo amp and the external amp at the same time. Its one of the other but not both at the same time.

[szabo016]

So is it possible that the sound could be worse. because the amp is only 4x40W but the stereo is 4x50W

[SilvrEclipse]

Is that rms power or peak? No I highly doubt it would sound worse.

[szabo016]

For the stereo it is 20 watts RMS/50 watts peak x 4 channels. For tha amp the user guide says its max power output at four channels is 40Wx4 and it does't say "RMS" but i believe that that is where is says Rated power output for four channels is 16Wx4... Thant seems really low

[szabo016]

It also says rated power output at 2 ohms for 4 channels is 25W x 4... The other specs were for 4 ohms... I am not really sure what that means

[szabo016]

Is that what you where talking about??

[vanilla gorilla]

A head unit alone isnt going to push more than like 18 watts I think.