Joshua022

Im wondering if I got a freaky nice kicker comp 8" sub and swapped it into where the factory sub is would it help with the lack of thump any, that the factory system is totally lacking?

Or would it be the same thing just because the factory amp sucks?

07azhhr

The amp is the biggest issue and will not allow you to get much if any better sound. I know because I put a 10" sub in my factory box as well as put filler inside and dynamat over the entire POS plastic box and all it did was sound a little bit more like a sub should sound like but with ZERO extra volumn. The sub is not all that either but can hopefully take a little bit more wattage. I currently have a fiberglass 1 cft ported box in place of the stock box behind the factory panels with a Polk MM 8" sub but the box is actually built to fit a Morel Ultimo SC 2 ohms sub. I replaced the factory amp with a PPI Phantom 900.4 class D amp that is 900 watts rms but only 10.5"x6.5"xless then 2" in other words small. I have it mounted where the factory bins are behind the rear seats. I did have to cut a hole in the metal behind the factory box to fit the Morel and to get a tiny bit more air space.

barfan1

The problem with changing the factory sub is that the factory box is about .5 cubic feet in volume which is too small for most 8 and 10 inch aftermaeket subs, that is why people have bad results when switching them out. I am in the process of adding an 8" Dayton subwoofer in place of the factory one and powering it with a Kenwood amp. The specs on the Dayton match up with the factory box quite well so I will see how this works out. I can't have a huge box in the back nor do I want to have to make a complicated custom box either, I just want to add a little more bass to the sound. Usually, if you match the box, sub, and amp really good, you can get a great result.

07azhhr

There are MANY MANY 8" subs that will play in a .5cft box. There are also more then a few 10" s that will play in this size. The problem IMHO is three fold. The AMP just plain sucks. The sub is only so so. And the box is so thin that it will flex and resonate and is only 4" deep.

The box part can be addressed by applying sound deadener. The amp and sub have to be replaced unforetuneately. Or you can do like me and one other have and build a new box in the factory boxes place.

FWIW many 8" subs actually can use smaller air space but will still perform in a .5cft box.

RE Audio 8" plays in a .3cft. The Polk MM 8's that I am using play in .35cft or .66cft or anything in between. Infinity's ref 8" also plays in a .35 sealed or can play in a .6cft ported. Kickers CVR 8" (used by a few on here) can play perfectly in a .5cft box. I am sure there are plenty more but you can see from just these three alone that it is more of a fitment issue then an air space issue.

I found Pioneer 10" and Rockford 10" that will play in this box. JL recommendes only one size box for their 10"s and it is usually .66cft and the factory box is between .5 and .6 from what I could tell. Again the air space is not the main issue but actually finding subs that are less then 5" deep and are not a brick in shape. They need to be more of the traditional V shape do to the front inside of the box.

barfan1

The main problem is finding an 8" or 10" that works in the .5 cubic foot box with a depth of less than 3.75". Otherwise , you have to put in a spacer ring and may also have to cut the factory trim panel to fit. I didn't want to have to do either so my choices became very few. The stock amp actually puts out a good output to the main speakers, but the sub output is too low even for the stock sub, you have to add another amp when you upgrade your subwoofer.

barfan1

So I finally got around to finishing my small stock sub replacement project. I replaced the stock sub with this: http://www.daytonaudio.com/index.php...subwoofer.html.

This sub drops right in, no problem. The specs on this particular sub match the OEM sub box very well, which I think explains the great results I achieved.
I then wired up a small Kenwood amp pushing about 120 watts RMS and wired the sub in parallel to show a 4 ohm load. Honestly, an amp pushing 70-80 watts would be fine as I have more than enough power. I still have to fine tune the sound but the amp is barely turned up and I am getting at least 100% more bass than the stock set up. With this modification and replacing the stock speakers with better units, the sound is now clear with good clean bass. I am very happy with the outcome. My total cost was:

4 Kenwood KFC-1662S speakers-$35( I already had one pair)
1 Dayton sub-$30
1 used Kenwood amp(KFC-428S)-$35

So for $100 the sound in the car is 100% better, is it ground shaking or ear cracking-no-but with two small kids, very little extra money, and the need to be able to use all of the cargo area with no modification, this works perfectly for me.

chefhhr

Did you wire the amp parallel with the existing amp or get rid of the existing all together? I don't want to go through the hassle of running wires for a new amp.

barfan1

On the Pioneer system, the factory five channel amp powers all of the speakers including the sub. In my car, it now poers just the six main speakers. The sub is powered by a small Kenwood amp I added, really easy, all you have to do is use 3M Quick taps and just tap into two of the rear input level wires going into the factory amp, I used the left rear inputs, they are brown and brown/white and the pink remote wire. Use an RCA to speaker wire adapter, Kicker makes one, and then run a short power and ground wire and you are set. If you are running a "mono" amp, most only input the left side signal so there is no need to to tap into the right side low level inputs.

The factory amp's sub channel barely powers the factory sub, it won't power anything better than that so you have to upgrade to a separate amp for the sub.

This is actually a really easy upgrade and is all done in the back of the car as that is where the battery is so no long runs of wire to snake.

JAMIROBri

Do you have pictures of where you mounted the amp? I have a small old school Rockford Fosgate Punch amp that I never used sitting in a box at home. It may be perfect for this!

Brian

barfan1

I'll see if I can get a picture, what I wanted to do was mount the new sub amp right next to the spare tire, but the amp was just a little too wide for this. I think my the amp I used measures 7" x 10", pretty small. So I went to Plan B, which was to just mount it on the spare tire cover. I drilled one hole to pass the wires through and screwed the amp down and I was done. Amp is totally hidden and takes up almost no storage room under the rear shelf/carpet.