350xhilaration

My expectations for this build are not for competition or show, but to achieve a decent sounding system on a modest budget. ($900)

So far, I have spent $804 on everything in the thread title plus 2 amplifier wiring kits and a power distribution block. I haven't purchased MDF or any other misc stuff yet.

I've already replaced my stock Head Unit with a Kenwood DDX470 and used a Metra harness to connect it to the factory Bose stuff. I'll keep the DDX470 and get rid of/bypass all Bose equipment.

I'll be building the box, wiring the car, installing all the speakers and amps myself to keep costs low. I'll try to get pictures as I proceed with the different steps of the process.

The plan is to replace the existing front and rear speakers, remove the existing subwoofer and its mounting panel, build a rectangular box based on dcains' box dimensions and mount the two amps side-by-side in the glove box behind the passenger seat. I am planning to modify dcains' box slightly to accommodate my sub. The Alpine sub has a vented cone and I want 3/4"-1" of space between the vent and the back of the box. The proposed modification is a 3/4" tall MDF ring that will be sealed and screwed to the top of the box under the sub.

So far, I have sketches (attached) of the proposed sub box and the layout on the MDF to minimize cuts and maximize the use of the material.

I'll try to post as much detail as I can so other folks that may be interested in a low-budget, better-than-stock build have a place to get ideas.

Feel free to ask questions, but please don't start a flame war here on the gear I chose. I've made my decision and am sticking to it. There are soooo many choices, opinions, and reviews of gear, it boggles the mind. Are there better choices than what I made? Probably. Are the selections of gear I made going to blow the doors off the Bose factory stuff? Absolutely.

350xhilaration

Most of the gear arrived.

Now to find some time to build the subwoofer box, install all the speakers/tweeters and wire everything.

dkmesa350z

iTrader: (41)

looking forward to seeing your progress

350xhilaration

It may be a slow build as I have a very active work and family life.

Tonight, I started pulling interior trim pieces. Pics attached.

I started with the door sills and worked my way back. Door sills easily snap straight up. The panels that go under the seatbelt upper pivot, those aren't too bad. Take your time, pull the weatherstrip from the car body enough to see between the panel and car body. I used a large prybar to slide between and apply a bit of pressure on each of the attaching clips to pop them from the body. In the hatch area, I started at the rear and pulled gently until the first clip popped, then I slid my hand between the panel and body and worked the other clips loose.

The most difficult piece was the wide section that covered both speakers. It seemed to help to start at one side and pull slightly to the rear of the car to get the lower panel that remains in the car to detach from the piece I wanted to remove. After getting one side detached and pulled backwards a bit, I did the same on the other side. Then I went from one side to the other and detached. First, you must get the two panels separated by pulling toward the back of the car, then you pull upwards. Once all the clips have detached, then "hinge" the piece above the subwoofer and the glove box and push slightly backwards.

350xhilaration

So, I had some free time today to pull more panels and mock up a cardboard box for the subwoofer.

After removing all the panels and center console, I was able to get a good look at the space where I want to mount the subwoofer. It appears Nissan uses the same body for US and "overseas" versions (makes sense) based on the mounting tabs hanging down behind the subwoofer. These mounts are used on the "passenger side" to attach a bracket that is used to attach the glovebox which, of course is dependent on what side the passenger will sit. In the US, these two mounting tabs on the driver's side serve no useful purpose, so I removed them to allow for more space in the compartment.

I had a Google Sketchup of the dimensions I wanted to use, but wanted to mock up a cardboard box before cutting the MDF and assembling. Turns out, I'll have an additional 1/2" in height which is great news. I won't need the spacer I had thought I'd need to achieve the amount of clearance below the vented cone.

I'm finished for the day.

Any questions, feel free to ask.

350xhilaration

A few more pictures

350xhilaration

Started on the subwoofer box.

I did the best I could with a Ryobi 18v circular saw. Luckily the guy we bought the house from was a cabinet maker and he left some of his work tables behind. I was able to screw the MDF to the table and allow the blade to cut into the table 1/8" or so.

I screwed the MDF down and used a straight edge as a guide to keep the cuts as straight as possible. I found a piece of molding in the garage that was long enough to span the MDF. I measured the distance between the blade and edge of the shoe and screwed the straight edge (molding) down and ran the saw keeping the shoe tight against the guide.

The attached pics are of the pieces being cut then put together using gravity. I haven't screwed or glued anything yet.

Next is to cut out the subwoofer hole and figure out how to assemble this bugger as square as I can with no clamps or other real woodworking stuff.

350xhilaration

Realized after I was done cutting the panels that my jigsaw had been stolen in April of 2011. Luckily my wife was at the mall when I realized I didn't have a saw. Called her up and she picked up a cheap-o jigsaw from Sears.

I started this evening by making a stand to secure the top panel while I cut the subwoofer hole. I needed to raise the panel high enough for the jigsaw blade to clear while making the cut. I used a scrap 2x4 that was propped up in the corner of the basement.

I needed to mark the panel so I criss-crossed the box from corner to corner to find the center, then drilled a hole there. Next I had to figure out a nice way to make a circle. Easy, scrap piece of MDF, a drill and a pen. I measured half the needed size of the cutout and drilled two holes in the MDF. I drilled a hole slightly larger than the screw on one end and made the pen a snug fit at the other. Spin it around and I've got a nice circle to cut out.

Once I cut the panel, I made a jig out of a scrap piece of thin metal angle I found in the garage. I spaced the holes in the metal as I wanted and used the jig on the face and edges of the MDF to make sure my holes lined up. I'm certain there are better ways of doing this, but I have no clamps or real woodworking equipment, so I made do with some ingenuity and scraps. (remember, this is a budget build and the jigsaw at $30 of my $96 wiggle room) Since I'm talking about $$$, I spent $20 on the MDF and wood glue. I had screws already. So I was at $804 before the sub box build and now I'm at $854. Still under budget.

I went around the box and drilled more holes, countersunk them and attached all the pieces. I dropped the sub in and took it to the car for a test fit. It fits!!

I changed my measurements slightly after the cardboard mock-up. the box is now 18"x12.5"x7". The additional height (from 6.5" to 7") gives me an extra 1/2" of clearance between the vented cone to the back of the sub box. I now have 11/16" clearance instead of 3/16".

I'll pull the box apart and glue everything and paint the box black. Then I'll probably start running wires...not sure yet on what I'll tackle after the sub box is done.

More pics:

350xhilaration

I ran the 4 gauge wire through the firewall and along the passenger side to the glovebox area. I haven't connected it yet as I'm not quite ready to connect things yet.

Instead of cutting into the grommet in the firewall, I decided to strip back the tape of the existing wire harness and run the power cable alongside the other wires through the grommet. I removed both covers near the battery to make it easier to work. Pop up all the push-in fasteners and remove. The cover over the grommet slides toward the front of the car and out from underneath the windshield. By removing both covers, there was a ton of room to work. To make it easier to get the insulated 4 gauge wire to slide through the sticky rubber grommet, I tucked an ArmorAll wipe into the harness and around the 4 gauge wire. It made it SOOOO easy to slide the wire through and it didn't leave behind and wet residue like a silicone or other spray would have. I was able to push the wire through with ease.

Once I got the length of cable I wanted near the battery for future connection of the in-line fuse and connected to the battery, I routed the remaining cable along the passenger side of the car and to the glovebox. I then ran speaker wire from the glovebox to each of the front kick panels. I left enough speaker wire (I hope) at each kick panel to go through the existing harness and into the door. I'll add either a grommet or some plastic loom to the wires in the rear where they enter the glovebox area.

I finished the subwoofer box. It's been glued, screwed, sealed, and painted. I wired and installed the speaker terminal and the subwoofer. It's air-tight and I tested function with my home stereo (full range) for a few moments. Full range sounds like crap, but when the bass hit, it sounded really good. It might be more "thump" in my Z than I wanted. I guess it's better to have too much and be able to adjust it down than to not have as much as you want. A bit of a challenge getting the sub box rotated into the hole properly, but it does fit with enough clearance above the sub.

Pics attached.

350xhilaration

Yesterday I tore into the doors to see how much work would be needed to get the wiring run and speakers installed.

I modified the existing factory connector by drilling through unused space and routing the wire pair through the new hole. Used another MY350Z thread for reference. It wasn't extremely difficult, but the worst part was getting the connector back together at the jamb.

For the front speakers, I gutted the Bose speakers by removing the cone and cutting the angle support braces. I then drilled holes around the outside lip and snapped pieces off and sanded any jagged edges. I was then able to mount the new Alpine 6.5"s and use the Bose plastic housing as a spacer. I ran out of female spade terminals, so the passenger door isn't back together yet.

For the tweeters, I chose to trade-off some speaker real estate for ease of installation. My new tweeters are about 25% larger (at least the grille is) than the existing hole. Instead of getting into a fabrication job of holesawing/glueing, or other means to get my swivel tweeters installed, I removed the existing tweeters and disassembled the new ones and mounted them in place using the old mounting hardware. I lost a little bit of area for the tweeter to play through, but install took 2 minutes per side. I'm sure I'll be able to hear the tweeters just fine through the existing opening.

Rinse and repeat for the passenger side.

I also started measuring up the glovebox for amp placement. Some pics attached.

This is not a complex or flashy build and I'm not looking for compliments or critiques, but I found it frustrating to search the forums only to find incomplete threads with no pics or bits and pieces of a build. Does any of this help anyone here or should I just go stop posting and delete the thread? I'm happy to share, but if it's a waste of time and posting has no value to others, I can easily stop.

350xhilaration

More pics...

350xhilaration

Done.

Everything has been installed and all trim reassembled. I'm very happy with the results. It sounds great!

DarkCreep

iTrader: (1)

No pics of radio or everything assembled and installed? Come on OP!!

dcains

iTrader: (15)

Nice workmanship and a clean-looking and stealthy install. I used polyfill in my sub box, rather than a cat, but yours probably sounds good, too

jes1888

iTrader: (2)

me, on the personal side, had to put the tweeters outside of the OEM moulding, that freaking grille muffled the sound a LOT!!! so i just made a hole there and put the tweeter, it was larger and didnt went as clean and stealthy as i wanted but i tried. also, for the sub, you could have just spent 200 dollars for a infinity basslink and saved a lot of hassle in there for the bass department. It's an amazing piece of hardware. it will not rock your neighboor's glass windows but will fill the music in an awesome manner for a shoebox like dimension package

350xhilaration

My apologies. Felt as if nobody was following along or cared to see another build thread, so I stopped posting details.


I moved the power and speaker wires that are shown in the picture above running through the center area. I ran the power down the passenger side near the seatbelt retractor and secured/loomed it. The speaker wires on the passenger side, I ran below the retractor and then up and across the front of the subwoofer box area and fastened to the existing wire harness.

I mounted the power distribution block under the passenger side glovebox and mounted with zip ties to the rear of the seatbelt retractor. I ran ground wires from each amp individually to a single bolt in the center of the car (where the power and speaker wires are shown above).

My glovebox had a thin, carpeted board that sat above the plastic recessed cubby in the glovebox. I cut holes in that board and ran all my wires up through and connected to the amplifiers. I attached the amps to that board with some screws and nuts.

I took a chance on my wiring skills by bolting/securing/zip-tieing/looming everything inside the car before applying power to the system. Once I had everything wired and secured, I wired in the in-line fuse under the hood and connected power.

A turn of the key and a push of a button and everything came to life!! All speakers played in their respective positions, the sub was thumping and I was grinning. It's been almost a month and I haven't had any issues.

I have adjusted the gains and filters a couple times on the sub and 4 channel amp to get the more "balanced" sound I wanted. At first power on, the sub was waaaay overpowering everything else. I've since throttled that back and can adjust the sub control in-radio if I want more bass.

All-in-all, I'm very happy with the way it turned out. It produces exactly the level and quality of sound I wanted.

I figured I might lose a bit of sound from the tweeters, but like I said, I made a trade-off to ease the install and keep the stealthiness. I'm still OK with that decision.

I'll try to get some pics of the amps, but other than that, there really isn't much else to show. It looks like a stock interior aside from the head unit.