bizron

iTrader: (1)

Hey guys,

After getting tired of the lack of bottom end in my Bose equipped RX8, I took the plunge and went for a real solution.


Before my rx8, I had a grand cherokee...before that I had an eclipse (third gen)...and before that I had an older eclipse (first gen)...all of these vehicles share the cabin's airspace with the trunk. I've never had a system with less than 2 12" subs, but I really didn't want to take up that much room in my car.


Knowing that the rx8's electrical system was a bit weak lead me to go with a class D mono amp and one 10" sub (to save trunk space). I'm 27 now, so impressing people is no longer a goal. I'm only interested in how it sounds to me inside the car. I was pretty nervous because I've never had a system this small.


Crutchfield was running a special on the Alpine MRP-M450 amp so I decided to jump on the deal. ($150)


After getting the amp, I started subwoofer shopping. The M450 does 400 watts rms x 1 @ 2ohm, so I needed a 2 ohm sub that could handle somewhere around 400 watts.


I shopped and read reviews for quite a while and decided on the Infinity Kappa 104.7w subwoofer.($180)


It has a switch that changes the series/parallel wiring without having to wire the voice coils. It is rated for 50-350 watts RMS (1400 watts peak power), so I felt it was a good match.


It has a top mounting depth of 4-13/16", so I knew it would go well in a shallow box too. The sub recommends 0.53-0.98 cu. ft. of airspace for a sealed box, so that also fit the bill.


For the power, I bought a Rockford Fosgate 8 ga amp wiring kit from best buy. ($40)
I'm using a Navone Engineering LOC with the signal tapped after the bose amp. ($15)
I tapped the remote wire at the rear power receptacle.


I built my own box out of 3/4" MDF from Lowes and carpeted it with black automotive carpet from wal-mart.
The box's dimensions are 24" wide x 8" deep x 13" high.


This gives the box 0.97 cu ft of air without the sub.
I had to make the subwoofer box 24" wide to mount the amp next to the sub. I wanted the height to be 13" because I wanted it to fit snugly up against the metal support bar on the rear deck. The only real dimension I could alter was the depth, which needed to stay around 8" for it to be stable (don't want it tilting backward!).


box materials - wood glue, silicone, caulk gun, 2" drywall screws, panhead sheet metal screws, scrapers, wood filler, carpet, etc.

Total cost of box materials $70.



Now to the build photos..........




Yes - I need a rotozip




Luckily my jigsaw did fine.

I recruited the help of my wife to hold some of the pieces while I pre-drilled, countersunk, glued, and screwed the pieces together.










After hooking up the system in the car, I could tell that my fears weren't needed. This 1 10" sub is exactly what I needed to fill out the sound in my car. It can do way more than fill the lows if I want it to. It gets very loud inside the car, but not outside of the car. That's fine by me.

Here are some shots after carpeting the box. I may try and clean up the wiring some more too.








I still have lots of trunkspace left too.








amp $150
loc $15
wiring $40
sub $180
box $70
8 ga pwr/gnd terminals $10 - 5 pack from circuit city

total cost $465

The sub is a great match for the amp and it bumps pretty hard. I am very pleased with how it turned out (this is the first time I've built my own sub box too).



What do you guys think? If you have any questions, just ask.

bizron

iTrader: (1)

here's a pic of the subwoofer I chose

firebirdude

iTrader: (3)

Glad you're happy!

I don't know how the HELL you managed to spend $180 on that sub. They're under $100 all over the place. You got served man.

Maybe a couple things I would done differently, while still using the same materials/amount of effort. First, I think I would have mounted the amp on the back of the box. It's pretty small, so I'd move it all the way to the bottom of the box to allow the box to slide against the back seat as much as possible. (Slanted back seats) Moving the amp hides your wiring 100%. Next, it's a single relatively low-power 10". I probably would have used 1/2" MDF to build the box to save on weight. The box is small and sealed, 1/2" MDF would have easily done the job. And finally, could the box be made any wider? Looks like there might be some room along the left side? Or is it hitting along the top? With sealed boxes, bigger the better for the most part.

All in all. Still looks decent. Just giving a little constructive criticism with my .

Socket7

Props for building your own box! thats hard work! I went for a 4080 box myself for a more integrated look.

Personally I don't like amps mounted on sub boxes. solder joints do not like lots of vibration, and I'd rather not risk my amp that way. You could probably mount it on the back of the rear seats and hide the wires.

A lot of people discount 10" subs as not loud enough. or not big enough. I think it's nonsense. With a properly tuned system in a car, a single 10" is more then enough.

Bumble_Bee

For a first time build... you look like a pro.

bizron

iTrader: (1)

I got served by Crutchfield, who unlike those other websites where you can find it for that cheap, are authorized internet retaillers for the products they sell. That means that the factory warranties for the subwoofer and the amp will hold up (3 years for the sub!) vs. the typical 90 day, 1 year, or nada warranty that comes w/the stuff you get off of e-bay or some other gray market retailer. I did shop around before I got the sub, and decided that purchasing from a reputable dealer (who is also 40 mins away from me) was the way to go. I don't feel like I got pwned

I've bought stuff from OnlineCarStereo.com before and was pleased with the results. When I could spend 30 more for the sub and get the full factory warranty, it was a no-brainer.

I thought all boxes needed 3/4" mdf... 1/2" would've been nicer to work with, but I don't think lowe's had anything but the 3/4".

I may move the amp to the back or to the seat like Socket7 suggested. That black plastic backing to the seats doesn't feel very secure though.

The box couldn't be any wider, because it touches the paneling near the top of the trunk.

Thanks for the props guys...For my first time building a box like this, I am really pleased with the results.

firebirdude

iTrader: (3)

I fully understand the issue surrounding authorized retailers. But when it's a small item such as this, who cares. Look back at your electronics past. How many items have failed within their warranty period? And would you honestly spend the $35 to ship that sub and wait 3 weeks for Infinity to repair/replace it? And if you would, their warranty is filled with little caveats that would allow them to possibly turn down your repair. We're talking $90 versus $180. It's a no-brainer for me too.

Socket7

The plastic panels for the rear seats are pretty flimsy, but it'd be easy to build a mount out of left over MDF that bolts to the cross brace behind the panel

kevinD1226

nice work man! hope it sounds exactly how u wanted it too

Z0oMzo0m

iTrader: (4)

i was thinking of doing a custom box myself. but wasnt sure how to hook up with stock headunit.. is it possible? i just want a little more bump. are there aux. jacks in the back of the 6 disc changer??? idk... suggestions on hook ups? how do you do this i know like on other systems it went through a remote wire and some aux. cables from back of cd player to amp..

bryanRX8

Hey just wanted to let you know that this thread helped me a lot. I took the same design, but just changed the demensions a little bit because of the size of my sub. It is also a 10", but its a low profile, which is why we decided it would fit in the spare tire impression. Here's what it looks like:
http://photos-d.ak.fbcdn.net/hphotos..._3431191_n.jpg

and here's what it looks like in the car:

http://i37.tinypic.com/34sqko7.jpg

i know the wires are showing, but i did not have enough ground cable length to run it completely around, so i had to shorten the power cable, which in turn led me to just having two sources of cables.

The amp mount is indented about 1.5", so it's level with the sub when its being used. That way, if i finish deciding how or what i'm going to use to cover it (most likely plexi glass) then it will look even.

I find this way also enables more storage use, just in case i need to run boards or my snowboard for spring break, it will be accessible to the trunk.

Austin Dicken

i have two subs that im trying to fit and get into my car. which i actually have already fit and wired some power cables to my amp and the subs. i have two 12' CVR kickers with a 800 watt amp. i heard it in my buddy's car and i know it sounds great. the only problem im runnning into is hooking it up to my stereo system. i'm trying to stick with the stock stereo system, but can't find anything on it or what it looks like.


please help trying to g[IMG]file:///Users/austindicken/Desktop/DSC03138.JPG[/IMG]et my car bumping soon.

if you want to see what i have so far check out my pics can't figure out how to get them on here so you can see right away.


[IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03153.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03160.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03154.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03163.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03141.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03140.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03161.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03164.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03166.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03137.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03155.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03146.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03142.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03157.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03138.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03156.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03165.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03147.JPG[/IMG][IMG]file:///Volumes/Untitled/DCIM/101MSDCF/DSC03164.JPG[/IMG]

cornholio135

iTrader: (2)

one of our local members bought my old 8" amplified Bazooka and my old electronic crossover with bass remote. Sounded really good in his R3. no box to build takes less room...

here is a pic

Kenalk

Nice build! looks like a professional job. One thing i was wondering is how you kept it from sliding around? is it attached to anything?

9krpmrx8

iTrader: (46)

5 years since the previous post...

Steve Dallas

And the tie-down straps are obviously obvious.

Kenalk

well I still didnt see them...we're all friend here, right?