Amp Speaker Question

bpd138

I have a NOOB question so please don't laugh!

I have installed a Kenwood DNX8120 in my new Z. Pictures are in one of my albums. I have (don't laugh) Polk DB651 6" two way speakers in the doors and Polk DB351 3.5" speakers in the rear. I left the stock "tweeters" in the dash for now because I don't know what to do with them.
Using the advice of another forum member I have purchased an Infinity Reference 475a amp, which I haven't installed yet.

If I am correct the Kenwood head unit is rated for 22watts continuous output for the four speakers. My speakers are rated at about 45watts continuous output. To my untrained ears they don't sound that bad hooked up to the head unit without an amp.

Okay heres the question(s).
If I go through the trouble of installing the amp;
1) Will I notice that much of a difference in sound quality?
2) If i don't hook up the amp will I damage anything?
3) Any suggestions on how and where to mount the amp and also where to run the power wire through the firewall?

Once again you guys are great.
Take care,
Willie

rreign

I am no professional here, but I do know my sh**. You can read some of my other threads/posts if you want. Also you can check with Jeff on here as well. This is my thoughts and suggestions...

1) Yes, you would notice a significant difference in SQ (sound quality) and SPL (sound pressure level or dB) However, you don't need the amp. You will have 4x 2way components plus the OEM tweeters. That is a lot of highs. Almost would be too overpowering without a sub. Your 6.5"s are rated for 6 - 55W RMS and your 3.5"s are rated for 4 - 35W RMS. With your new H/U you are right on the inbetween of the max RMS anyway.

2) Like I mentioned above, all of your speakers fall right around the middle of their peek RMS. Also they are all 4Ohm speakers. Your H/U is 4ohm as well. I don't foresee any problems running this system from your H/U alone.

3) I have done a lot of research on how, where guys are running their amps. The easiest and most efficient way that I have found is to remove the foam piece that's under the rear support bar and use the open space that will be provided there. You can run your speaker wires directly from your wiring harness, through the center console all the way back to your amp. No wires will ever be seen. Jeff always runs the power wire through the fire wall near the battery. He has to drill a hole through the firewall and put a rubber grommet in the drilled hole, then run the power wire through that. Then run the power wire along the passenger side of the car to the amp.

I am sure other's will chime in with any tips and tricks. Hope you can get it all figured out. Jeff is a great source of info being that he has already done a couple of installs already.

rreign

no response/no takers?!

david712370

Hey Willie,

I would strongly recommend that you get an amp. One reason is that you got a nice head unit that has higher preouts that most other units. I believe yours is 4 or 5v. where most others are like 2v so this is a bonus with that head unit, so you might as well use that additional feature that you paid for. You can install most of the amps where the foam is behind the bar that runs across the car. I plan to put two amps there.... one for my subs and one for the 3 way components I have. I feel like your set up is decent.... but I personally have chosen just to have front speakers....I was worried that i wouldn't have sound from the back but the sub takes care of that. So technically I have 3 left front speakers and 3 right front speakers. I am very satisfied with that set up.

Another problem i forsee is that if you power from your h/u you may not be able to listen to ur music as loudly as you may like.

bpd138

Hello,
I'm in the process of installing a Infinity 465a amp. I mounted it to a piece of 1" pressboard and put it under the foam in the back. I had to cut one of the legs of the foam down so the foam woudl fit flush. I Also had to do some fancy cutting of the mounting board to make it fit over the bolts sticking up out of the floor! lol It turned out pretty good and dosen't move around.

I installed the rear speakers today too. Because I had already run the speaker wires from the HU to the rear prior to buying the amp and the speakers, I hooked them up to the head unit just to see how it would sound. I like the sound because it fills the car better. The Kenwood DNX8120 has surround sound and SRS Wow and it sounds pretty good when its set up right. Tomorrow I will finish installing the amp. I have already run the power wire from the battery to the amp (not connected yet)

The reason I was waiting to finish installing the amp is that I was waiting for my Swi-Jack and rearview cam to come in so I don't have to keep taking the dash apart. Well the Swi-Jack came in but the cam didn't so I bought a video cable so I can install everything and just connect the cam when it comes in.

I've had every body panel out of the car twice now. It really isn't that hard to do if you do it in the right order.

Once again thanks for the advice and help.
Willie

DIGItonium

Nice! With a stronger amp, you'll enjoy cleaner sound especially when the music peaks regardless of the volume level.

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