View Full Version : 2008 GMC Sierra build for four 8" subs in fiberglass ported box with 3" seat raise

03-25-2012, 06:11 PM
Hey guys, here is my build. This will be taking me a while as I am taking my time on this so this thread will be going on for a while.

This is what I am doing:

Removing rear factory sound deadening material
Dynamatting back wall
Making amp rack out of 1/2" mdf wood painted black
Mounted 4 channel amp, 2 distribution blocks, Audiopipe 200a external fuse, Rockford Fosgate 3Sixty.1 Digital Sound Processor, Focal K2P crossovers, and 400 watt Power Inverter on back wall
Re ran all of my wire
Flush Mounted tweeters in rear doors.

Equipment used

Front: Focal Utopia Components
Rear Focal K2P Components
4 channel amp: Audiopipe AQX-360.4 (125w x 4 @ 4 ohm, 250w x 4 @ 2 ohm) (Thinking of bridging this amp to get more power to my front Focal Utopia's and adding another amp for my rear Focal K2P's
Mono Amp: AudioPipe 3001D (two 1500D's strapped internally. 1500w x 2 @ 2 ohm or 3000w x 1 @ 1 Ohm)
Kicker PDK1 1/0 awg amplifier wiring kit
Big 3 upgrade
6061-T6 Aluminum square tubing for 3" seat raise.
Fiberglass bottom box. Im not sure how much airspace I will get. I wont know till I get the box finished, but it will be ported to 30hz. cwill5 is helping me out on building this box and I will be getting plenty of stuff from him for my build and my friends build I am doing next week in his Ford Escape
Sealing off the 4 holes in my doors with 1/2 wood. ***** that there are so many holes in my doors. A couple holes in each door are uneven so this is becoming a pain in the rear and very time consuming. I already had them sound deadened. I have the sound deadener peeled off, but will be putting them back on and then laying another layer of Dynamat on top of it so I will have two layers.
3/4" speaker ring adapters in the front for clearance issues and the same for the rear, but this isnt because I have clearance issues; this is so that I have them installed so they will be mounted evenly. The rear stock speakers have mounting adapters that are uneven, so I am making sure that there are no spaces between the speakers and the door.

Future Upgrades
External Battery (Either AGM or Deep Cycle. Currently working on a deal with Bettr n' Revrse to buy his battery. This is one good guy here by the way. If he has anything for sale that you need, I will back him up as a reference.

Mechman 270a alternator (I am getting this from a guy here on the board and come to find out, he lives right up the road from me and in the same neighborhood and down the street from two of my friends. One friend is right around the corner and my other friend that lives 3 blocks away. He is an authorized dealer who is getting his custom car audio shop. He is a dealer with Digital Designs, Mechman, Sundown Audio and many many other high end audio equipment manufacturers. I met up with him and saw his garage and I was in shock, awe, and completely amazed with all of his boxes and his Ford Expedition SPL competition truck with two Steve Meade custom 18's in a huge massive box. I recommend this guy highly. If you need anything, contact him and he can get it for you.
He is cwill5 I highly recommend him and will back him as a reference

I am looking at getting either of the following. They are in order in preference from top to bottom

Four SA-8 V2's
Three - Four Digital Designs 1508's (May have to go with 3 due to air space I may end up with. Money is a factor too.)
Four Skar Audio VVX-8
Four Alpine Type R 8's

Ok, I know I am going to get this question asked alot as I have already mentioned it and I have been PM'd about it several times so I am just going to list exactly what I bought and from where.
I bought my metal from Online Metal Store | Small Quantity Metal Orders | Metal Cutting, Sales & Shipping | Buy Steel, Aluminum, Copper, Brass, Stainless | Metal Product Guides at OnlineMetals.com (http://www.onlinemetals.com) If you type in "aprilfools" you will get a 10% discount. This coupon code has been around for like a year now and still works

Quanity: 4
For the Front and rear sides
2" x 3" x 0.25" 6061-T6 ALUMINUM RECTANGLE TUBE
3.000000 Inches (L)

For the middle larger brackets

Quanity: 2
2" x 3" x 0.25" 6061-T6 ALUMINUM RECTANGLE TUBE
6.000000 Inches (L)

For the seat belts

Quanity: 4
2" x 3" x 0.25" 6061-T6 ALUMINUM RECTANGLE TUBE
2.000000 Inches (L)

And for the extensions for the rear hooks, I got this

Quanity: 3
0.12" T-316-2B Annealed Stainless Sheet
2.750000 Inch (W) X 3.000000 Inch (L)

03-25-2012, 06:25 PM
This is the truck it will be going in. 2008 GMC Sierra 1500 SLE2 Crew Cab, Texas Edition, Preferred Package, Convenience Package, 20" wheels, painted to match power, heated, and power fold in mirrors, painted to match door handles, Power Adjustable Pedals, Rear Back Up Assist with rear sonar sensors, Stabilitrack on top of the standard Traction Control, Rear Locking Differential, 3.73 rear end, 20" Polished stock wheels, Towing Package, 5.3l Flex Fuel, EZ-Lift rear lift gate assist package with locking tail gate, fog lights, leather bucket seats, Center Console, Driver and Passenger 6 way power adjustable seats

Aftermarket and Modifications:

Billet Aluminum Grill (Removed Factory GMC Emblem in the middle. Brushed Stainless Steel on the surface and inside is black ((Where you stick your fingers between the grill is black)

Painted to match black front and rear bumper (Originally Chrome)
Painted to match black outer grill trim (Originally Chrome)
Spintech 6000 Pro Street single in Dual Out at 45* exits
Black 4" diameter 18" long tail pipes/tips
15% Front Tint
3 1/2% Rear Door Tint
2 1/2% Back Window Tint

Stock Picture of my truck when I purchased it while sitting at the dealership while they were working up the paperwork for me to sign for my new truck:


First Grill. Here are couple pictures before I did the paint to match bumpers, grill, and grill replacement



Before and After Picture:

New Grill before painted to match modifications
http://i20.photobucket.com/albums/b236/TrancerZX/Truck%20Pictures/311955_10150301865619413_509279412_7896376_4227090 _n.jpg

http://i20.photobucket.com/albums/b236/TrancerZX/Truck%20Pictures/295914_10150318181844413_509279412_8013796_8687950 85_n.jpg


After Pictures with my painted to match Modifications:



03-25-2012, 06:38 PM
I removed my center console to see if I could fit my Audiopipe 3001D under my center console. Its simply too long for me to fit so this didnt work. If it was just a bout 6 inches shorter, it would have worked. If it was a couple inches wider it wouldnt have worked either. There isnt much room under there as I thought as under the deep storage, there is a metal bracket that gets in the way. Plus where there is a deep storage unit in the very front, it hits the floor.



The culprit of the deep front storage unit

Center Console without the insert:

The insert:

Removed factory sound foam and carpet before Dynamat





Me lining up my amps to see how to place them:


Figured out I could only fit one or the other amps:

03-25-2012, 06:46 PM
Mounting in progress. Before making my wires all pretty. You can see my T6 Aluminum square tubing installed for my 3" seat raise


Amplifier mounted


Distribution Blocks and external Audiopipe 200a fuse holder for Audiopipe 3001D


Getting closer


Rockford Fosgate 3Sixty.1 DSP and 400watt Power Inverter


03-25-2012, 06:51 PM
This should be good. Can't wait to see the glassed box. BTW, truck looks good.

03-25-2012, 06:54 PM
Pictures of my T6 Aluminum Square tubing for my 3" seat raise

Cutout for my amp rack for my middle seat belt system:


Passenger side amp rack:


Drivers side:


View from the front

The Build :: GOPR0191.jpg picture by TrancerZX - Photobucket (http://s20.photobucket.com/albums/b236/TrancerZX/The%20Build/?action=view&current=GOPR0191.jpg)

Middle Front Block


Rear Middle Block:


Passenger Front Block:


Passenger Rear Block


Drivers front and rear blocks


Middle Blocks


03-25-2012, 07:02 PM
This should be good. Can't wait to see the glassed box. BTW, truck looks good.

Thank you for the compliment.

The box will be fiberglassed on the bottom and the rear lip.

I got my idea and I am using this thread as a reference. His truck is an OBS 2001 Extended cab.


He was able to get over 5 cubic feet of airspace after displacement in his ported box and ran 4 RE SE 10's. I use to run two RE SE 12's in a sealed Subthump box with .83 cu ft before driver displacement so I wasn't using them to their full advantage. They were wanting more airspace. If I could run four RE SE 10's, I would. The OBS trucks, even the extended cab trucks, have more room under there than the NBS Crew Cab trucks unfortunately, so I wont be able to get 5.9 cu ft of airspace before port and sub displacement and just a tad over 5 cu ft after displacement like he was able to do.He tuned it to 32hz, so he had quite a bit of port displacement. About .75 cu ft of port displacement with 3 4" aero ports. He did a 4" seat raise. I did a 3" seat raise. Hopefully this wont bite me in the rear, but I didnt want to raise my seats that high. I plan on doing one precision port on firing one at the passenger door and one at the drivers side door. So even though I will be going with 2hz lower, which will make my port a bit longer, I wont be doing 3 ports, I'll be doing 2, so that should help me out with not having so much port displacement.

03-25-2012, 07:05 PM
That's all I have for now. I have made alot more progress. I worked till 4 a.m. last night so I have made alot more progress last night. I just need to take pictures.

Bettr n' Revrse
03-25-2012, 07:24 PM
Looking good man... You should join the FB group if your on...

03-25-2012, 07:27 PM
Looking good man... You should join the FB group if your on...

I believe I am on it. I dont ever get on it though

Bettr n' Revrse
03-25-2012, 07:29 PM
I kinda thought you where I wasn't sure though...

03-25-2012, 07:33 PM
With me being in the hospital for 3 weeks, having major abdominal surgery and me losing 35 pounds of muscle that I worked my @ss off in the gym for the past year, its all gone. My legs are sooooo sore from me working on my truck last night, picking stuff up, bending down, crouching, crawling around in my truck, etc... Oh Im so sore. Thank goodness I have hydrocodone or I'd be in some serious ankle pain from my car accident I had 5 years ago and the soreness would be killing me. Sounds like I need to be drinking some of my protein drinks in my fridge so that I can utilize that soreness and regain that muscle back in my legs. Got a Dr appointment next week and I am going to ask when I can get back in the gym. I am SKINNY as fock!!! I was ripped and tanned before I went into the hospital. Now Im pale and weigh as much as a 7th grader

03-25-2012, 09:16 PM
nice build nice truck too

03-25-2012, 10:07 PM
Good looking truck.

In for the build.

03-26-2012, 09:45 AM
Looks good with the painted bumpers. A lot better than the chrome IMO. Did you do it yourself or have someone else paint it? Awesome component choices also

03-26-2012, 10:21 AM
Everything looks good so far. Oh, and I want your factory 20"s, lol.

03-26-2012, 03:12 PM
Looks good with the painted bumpers. A lot better than the chrome IMO. Did you do it yourself or have someone else paint it? Awesome component choices also

Body Shop out of East Dallas. I know the owner. The truck is going back there in about an hour actually. Im getting a couple touch ups and getting my new Spintech Pro Street muffler put on with my 4" diameter, 18" long black exhaust tips. I should have the truck back tomorrow.

03-26-2012, 03:17 PM
Thanks for all of the compliments guys!

Well I got the speakers wired up last night. After running into a snag with one of my Focal Tweeters being screwed, I had to run over to Chet's house (cwill5) and grab some Digital Design silk dome T1 tweeters.

They are much much more laid back than my fronts. I havent done any EQing yet with my laptop on my Rockford Fosgate 3Sixty.1, but I dont have any tweeter attenuation with my Focal K2P crossovers. They are giving me a hollow sound. Seems like I need to do some EQing when I get my truck back so I can bump up that tweeter in the rear.

When I get it back, Im going to test fit the 40 part of the rear seat. I already know I am going to have issues with the middle bracket and my amplifier. I am going to have to shift the amplifier to the left about an inch and a half and I think I only have an inch. I'd really hate to have to trim my factory door trim. The other issue is that this AQX-360.4 amp from Audiopipe is extremely thick. Im hoping I wont clearance issues there either. If I do, Then I may have to mount it to the wall directly and just put some 1/4" wood in between it just to keep it away from rattling even though I have the wall Dynamatted. Man thats going to **** if I have to do that. I Liquid nails the hell out of that back wall

03-26-2012, 03:30 PM
Just incase anyone is interseted, since Im getting my new muffler put on today, I am selling my Flowmaster 40 Series muffler. There is nothing wrong with the muffler. I have just ran the same sound for the past 3 years and I am looking for something different. I live in the south, so we use sand, not salt on the roads, plus our winters here are mild. I think our average high temp this winter was 63*. So it just needs to be polished up and it would take the surface rust off and would look great, but who cares, its a muffler, no one will see inside of it anyway.

Single in, Dual out
3" in, 2.5" out






Sounds great. I can post up video's, from my GoPro Hero2 1080p POV camera, later when I get back.

03-26-2012, 03:50 PM
She's a beaut.

Hank hill would be proud.

03-26-2012, 08:59 PM
Everything looks good so far. Oh, and I want your factory 20"s, lol.

I'll let you buy them. They are in flawless shape. Piratically new to be honest.

I say I'd sell them to you because I want some black 20's.

03-26-2012, 09:06 PM
She's a beaut.

Hank hill would be proud.


03-26-2012, 09:08 PM
Well got some goodies in today.

Received a Stinger 1/0 in and out Amp and Voltage gauge. I needed this, because when I cut my 1/0 awg power cable when I did my install the first time a few years ago, I had it mounted differently. Now that I am mounting my Distrobution blocks on the rear back wall in the middle, I needed something to extend that 1/0 cable so I figured this would be the best way to do it. I wanted to make sure it was this style instead of having to crimp my own connections and screw them in. So this will fit well with what I am trying to do.





03-26-2012, 09:10 PM
utopia pics?

03-26-2012, 09:21 PM
So I received my Spintech 6000 Pro Street 3" single in, 2 1/2" Dual Out High Performance Muffler. This will be replacing my Flowmaster 40 Series of the same dimensions. This is going to give me a different sound. Just looking for a change. The FlowMaster muffler is for sale.

I just dropped my truck off at the exhaust shop to get the exhaust work done, alignment and possibly new struts since I am at 55k miles. I think I should be ok at 55k miles. I'll have to check my Owners Manual as I dont think I should have to replace these by now.

I also received my black 4" Diameter, 18" long Black Exhaust tips. Im not sure how these are painted, but the paint seems similar to bed liner type paint, but not nearly as rough. It has a rough surface. They look mean as heck. I slid the new tip over my chrome tip, so the diameter is definately bigger. Im hoping this will help improve my sound and give me maybe a lower deeper sound. I think my current chrome muffler tips are 3 - 3 1/2" in diameter.

Here are the pics

The Box

The Muffler


Width view

Inlet view

Outlet views
Right side

New Tail Pipes



Me sliding the front over my existing chrome tip. Its obviously backwards because the inlet is 2 1/2" and my existing chrome tips are 3"- - 3 1/2". But this gives you an idea of what it will look like


Well thats it for now. I know this part isnt car audio related, but hey, its a part of my build. I have video from my GoPro Hero2 camera of my Flowmaster 40 Series exhaust suction cupped to my tail gate. I haven't heard it yet. I will do the same once I get the new exhaust put on.

I wont get my truck back till late tomorrow if not early Wednesday. I am getting a couple things touched up at the body shop, but the exhaust shop wont be done with my truck till noon. Im having them go over my entire suspension. I may start looking at adjustable performance coil over struts, shocks and maybe an even bigger sway bar than the one that came with my Z60 Sport Suspension package that came with my truck.

03-26-2012, 09:25 PM
good thing I read your post before commenting like I was going to, I couldn't figure out why you wanted an earthworm shaped exhaust tip.

03-26-2012, 09:30 PM
Oh, I almost forgot about my doors. Here is some progress I have made on my doors. Sorry for the poor picture quality. It was taken when the sun was coming in straight in from the west. This is me sealing off my rear doors with 1/2" wood. Too many large holes. No wonder Im not getting any midbass.

Oklahoma Ingenuity at its finest. If you look closely, you can see that I had to drill a screw and made a washer out of the plastic from my door where I drilled out for my tweeter. I then tied speaker wire from that screw and washer to my seat hooks then to my headrest to pull on the wood (The wood is on the inside of the door with liquid nails) and then I started hanging any heavy tool as possible to pull as much as possible. I did this on both sides.



Progress being made on sealing up my doors

Before the top left hole


About to set the top piece in

I havent even done the fronts. I have to sound deaden my doors all over again. I havent decided if I should just put the sound deadener back over my doors even though its not sticking very well and then put a second layer of Dynamat or if I should take it all off and start all over again with my Dynamat. I'll be honest. Doing this whole sealing up the holes in the doors has been time consuming. Dropping things down in there, trying to come up with creative ways to get that thing I dropped in the doors out of there. Its a pain in the rear. I just hope all of this pays off.

03-26-2012, 09:33 PM
utopia pics?

Will have to wait till I get my truck back and open up my front doors to see what kind of holes I'll be dealing with there. The Utopia's, just like the K2P's have already been in my truck for the past few years.

03-27-2012, 10:08 PM
Well guys, I just got my truck back from getting my new black larger 4" tail pipes installed along with replacing my Flowmaster 40 Series muffler to a SpinTech 6000 ProStreet muffler.

I must say, I love the look of the new black exhaust tips. Since I have painted the chrome front and rear bumpers along with the factory grill black to match... I have gotton rid of all of the chrome. The only chrome I had left on the truck was the 3 1/2" exhaust tips. So now its official. Im fully blacked out (unless you include my rims, which I havent decided if I should save up and get some black 20's. I like my factory 20" wheels.) Let me know what you all think about me getting black 20's. I had some in mind. I'll have to start looking again.

Now as for the sound. WOW. Im simply amazed. Its lower, has more authority, deeper, nice low loud rumble, and its louder. It was well worth switching it out. I loved the sound of my Flowmaster 40 Series muffler, but it was time for a change. I'm one of those guys who like a change every 3 years whether its a new vehicle, different exhaust, different subs, etc...

I'll have to bust out my GoPro Hero2 HD 1080p camera and mount it to my tailgate like I did last week to hear my Flowmaster 40's. I did that so I could show all of you the difference in the sound and so when I sell my Flowmaster, people can hear how great that Flowmaster sounded. It's a great muffler. Nothing wrong with a Flowmaster 40 series. I enjoyed it. This would fit on a car or a truck. Its a single in, dual out. So if anyone wants a great sounding muffler, which I believe the Flowmaster 40 is the best sounding series muffler made by Flowmaster, let me know. Im selling it for cheap.

What do you guys think of the exhaust tips?

Here are my old tips. Sorry I dont have a better pictures. This is the only picture I have of the rear of my truck. This is when a couple of @ssholes decided to attempt and steal my wheels. They had all lugnuts off and got one wheel off and the jack fell on them so my drivers rear wheel was halfway on, halfway off. Good thing was, was that my truck was just a few months old so when I got a new wheel and tire, there was no difference in wear and tear. But hey, I got me a new jack out of the deal. I invested in Gorilla locking lugnuts for every single stud.

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/417575_10150589724949413_509279412_9115812_3250230 25_n.jpg

New tail pipes



04-04-2012, 09:46 PM
Looks BA with those tips. I might have to get one. On my seat lift, i realized id hit the amps as well, im just gonna make the top holes for the seats a 1/2 inch forward or so. I wish i thought to order my stuff pre cut.... its hell cutting through 3 inch c channel thats a 1/4inch+.

04-14-2012, 09:19 PM
Im beginning to build up my threads of useful knowledge, experiences, and answers again. Its been a while.

I need to get my laptop back so I can update my build log and add another build log of a customers car I did a couple weekends ago on my birthday weekend. He drove 250 miles for me to install it. I had him help since he wanted to learn so I had to stop every 10 minutes to help him, show him how to do something, redo/correct his mistakes, etc... or I would have had it done in two days instead of 4 days. Didn't help the first 2 days we were running around all over north Dallas getting stuff like an amplifier wiring kit that he said he already had, but it was cheapo junk and 8 guage power and ground and among other things like s "2000 watt amp" that actually only put out 400wrms at 2 ohm + more crap we had to chase down last minute

04-14-2012, 09:24 PM
Looks BA with those tips. I might have to get one. On my seat lift, i realized id hit the amps as well, im just gonna make the top holes for the seats a 1/2 inch forward or so. I wish i thought to order my stuff pre cut.... its hell cutting through 3 inch c channel thats a 1/4inch+.

Not sure if a 1/2" is enough, or atleast it wouldn't be for me because my Audiopipe AQX-360.4 is a bit thicker than most amps. I still haven't figured it out yet. I have been focusing on other things. If you do it or find another solution, please post your results in this thread. When do you plan on doing this? Im a out to install my subs next week

04-14-2012, 10:04 PM
Well guys, I can give you all updates but they will be without pictures till I get my laptop back or a replacement from Asus.

I ordered my 4 D4 SA-8 V2's on Thursday. Going to take 3 days to get them shipped out because they need to go through Quality Control first. So I'm looking at getting a sub woofers in by Wednesday or so. Right now I'm currently working on a temporary box made out of wood, not with a fiberglass bottom like I originally planned, although im going to still try to give fiberglassing a shot. So by my calculations of dentistry wood box only I can get 3.65 cubic feet of air space before displacement. I'm going to make 2 ports. 1 firing on each side at the rear driver side door and one firing at the rear passenger side door. I am also going to be doing slot ports. 3 different ports making them interchangeable to slide in and out just to play with them. The 30hz port will be in the box primarily. The other two are just to play around with.
1st - 30hz
2nd - 35hz
3rd - 40hz

I'm going to be doing a fiberglass front baffle for my subs so I can get some experience on fiberglassing. Maybe this will help me learn how to fiberglass so when i make my second box, I will have already played with fiberglass and will know how to fiberglass the bottom portion of the box. I was surprised that my calculations that I can go and get 3.65 cubic feet of air space just by building a wood box. So I'm making 2 boxes, one on each side and a middle piece to connect the two. Still haven't figured out how I'm going to mount my super long Audiopipe 30001D amplifier. I'm not gonna worry about it too much because this is only a temporary box and I am not going to use my plexi glass to make this box to all custom. I'll focus on my customization with the windows and the plexiglass with leds, logos in the plexi and everything else.

So when I do my fiberglass bottom box, I should be able to get at least probably 4 cubic feet especially by using Precision Ports.

04-20-2012, 06:20 AM
I ended up drilling the holes an inch apart. But i have not gotten to installing yet. I really cant lift the seats. My foot is still healing from the surgery. Its probably going to be a bit before i get to it.

Bettr n' Revrse
04-20-2012, 06:29 AM
I ended up drilling the holes an inch apart. But i have not gotten to installing yet. I really cant lift the seats. My foot is still healing from the surgery. Its probably going to be a bit before i get to it.

Idk how much of a reply youll get here man...

04-23-2012, 05:55 AM
I wasnt expecting one. I was just letting him know why I hadnt been able to tell him how it went yet....not sure what your getting at.

05-03-2012, 04:36 AM
I ended up drilling them an inch apart. Test fit it and it fits good. Plenty of space behind the seat. The angle is a little bit shallow for the seat back and it seems like way more than an inch closer to the front but it fits. I dont have people back there much anyways.