Sub box behind seat - available space?

[ItWillBeSlow]

Currently planning out my audio components and have everything figured out except what sub I want to use..

I am going for a single 10" or single 8" sub, and would prefer a JL W3 (8W3V3 or 10W3V3 ideally). The 10" W3 requires 6" mounting depth according to JL, not counting the space in front of the box required to keep the cone from hitting the seat.

I cant find any actual dimensions of how much available space is behind a factory bench seat, pushed all the way back. I am planning a basic triangular box and can make it long if needed to get the volume. I don't know if this depth is an option or not. I want to build something similar to @SactoJim from this post: http://67-72chevytrucks.com/vboard/s...58&postcount=3

If anyone has dimensions from the back of a fully extended bench to the rear cab, please share. I cant get my set in for a while to check this myself. If you have any similar "basic" triangular single sub boxes behind your seat please share as well.

Thanks!

[ChevyRacefan]

You did not say, but if you are keeping the in cab fuel tank, you are not fitting that deep basket sub in the truck.
The truck tank is about 9" deep at the bottom, and gets to about 5" at top. (off the top of my head, measure yours )
With seat all the way back, the seat bottom is maybe 3" from tank, top of seat is 1" (again ball park)
remember that the JL sub vents the voice coil motor in the magnet /speaker back. So you need a little space between the box back and the back of sub.
6 deep sub +1/4" for the motor vent, and then the box wood thickness x2(front panel and rear) So for example. 3/4" mdf x2 is 1.5"
7" (sub)+ mdf x2 1.5" you are at ,at least 8.5" + the subs mounting flange and air space for cone movement.
Totally forget it if keeping the in cab fuel tank.

[ItWillBeSlow]

Thanks for the reply. Gas tank is gone.

According to your estimates, it theoretically should work. Your ballpark says ~12" from back of cab to seat, with about ~10"-11" needed for the sub and cone movement.

I do have the tank out and can verify that depth, I just cant get my seat in to see where it would sit.

Any other comments and experience appreciated!

[1971Stepside]

I did the single 10" JL sub, but went with the shallow version. I posted a couple pics in my build thread and above in the pinned custom stereo thread. It sounds great and doesn't touch the seat

[ItWillBeSlow]

Originally Posted by 1971Stepside

I did the single 10" JL sub, but went with the shallow version. I posted a couple pics in my build thread and above in the pinned custom stereo thread. It sounds great and doesn't touch the seat

That looks great, thanks for the reply. I looked into the JL TW subs just now and they look like a great option for me as well.

How deep is your box at the bottom? Is your seat all the way back? What are you going to cover your enclosure with?

I like the simplicity of what you did, something like that is what I am after. I am thinking I will offset the sub to have as much storage on one side as possible.

[ChevyRacefan]

An other option for you as you are using a bench seat.
Is build a box that goes under the seat and put 2 shallow subs in it, one on each side, with a divider in the middle of the box.
subs firing down at floor, and 3 sides of box 1" taller than the front of the box(sides and back )
This way when you put the box in, and subs are pointing toward the floor, The longer sides and back, hold the subs off the floor, and the front of the box (facing the foot wells) has a 1" tall, full length of the box slot for the sound to come out of.
Think of it this way,( as I doubt what I typed above makes any sense without a photo.)
You build the box to fit under seat with say, 4'x14"x4.5" . Then you screw/glue 1"x1" stock on the box face (panel the sub(s) are mounted to, bottom, and sides.
now the box goes under seat subs facing down, and because 3 sides have that 1"x1" the 4th side is a nice long slot for the sound waves to exit from.

[1971Stepside]

That looks great, thanks for the reply. I looked into the JL TW subs just now and they look like a great option for me as well.

How deep is your box at the bottom? Is your seat all the way back? What are you going to cover your enclosure with?

I like the simplicity of what you did, something like that is what I am after. I am thinking I will offset the sub to have as much storage on one side as possible.

Box is 6" at the bottom and my seat goes all the way back. I'm using a Snowden Seat, but that will be very similar to the factory seat. It will be covered with red vinyl like the seat etc. I put my amp on the passenger side and will keep the drivers side for some storage of window cleaner etc.

[First c10]

Looks good 71SS.

I am working on my system as I install the interior.
Here is the speakers and box I built last year.

[First c10]

Here is my box completed!

[ItWillBeSlow]

Originally Posted by First c10

Here is my box completed!

That looks fantastic. What is the box covered with? Did you do it all yourself? What paint color is that?

Thanks for sharing

[First c10]

Originally Posted by ItWillBeSlow

That looks fantastic. What is the box covered with? Did you do it all yourself? What paint color is that?

Thanks for sharing

Thank you!
The box is covered with high grade vinyl. It’s so good I have a hard time telling the difference from it and the leather. The smell give it away.

I didn’t do the upholstery but did cover some of the wood parts myself. The tough pieces I had my upholstery guy do.
Check out my build thread it has more pictures of the stereo and interior.

[ItWillBeSlow]

Originally Posted by First c10

Thank you!
The box is covered with high grade vinyl. It’s so good I have a hard time telling the difference from it and the leather. The smell give it away.

I didn’t do the upholstery but did cover some of the wood parts myself. The tough pieces I had my upholstery guy do.
Check out my build thread it has more pictures of the stereo and interior.

Very very cool, thanks for sharing.

[ItWillBeSlow]

Originally Posted by First c10

Here is my box completed!

Will you post some more pics of what you did with your speakers in the corners?

[1971Stepside]

Finally had mine covered.

[ItWillBeSlow]

Originally Posted by 1971Stepside

Finally had mine covered.

Man that's clean! I really dig it, thanks for posting. I will probably borrow some ideas from this install when I get to this project. I cant wait to get past paint so I can start this..

[First c10]

These are the only pictures I have with me at the moment.
The seat belts are tucked back in the corner. I built a brace that bolted to the floor and the curved lip at the top of the corner to secure the corner panels too. You can see the bracket in the first picture

[ItWillBeSlow]

FirstC10 and 1971Stepside - I have a question for you guys, and anyone else with a similar box.

How did you build your floor for the box? Is it a piece of MDF resting on the rear "ridge" with some feet under it to support at the back? I have aftermarket cab mounts and an extra nut (original nutserts are stripped), so my cab bolts/nut extend above this ridge. This means I may need to raise my floor about 1" to clear the nut. I could double the bottom plate and cut a hole in the bottom one to clear, but wanted to see what you guys have done.

Regarding the clearance for the OE bench I started this thread for, it seems the back of the bench is basically a straight line from the rear seat bolt hole to the rear of the cab where the seat touches. I should have plenty of space with this sub (JL 10 TW1). I'm planning to offset it to the passenger side and use the driver side for storage.. i think.

Pictures probably do more justice than my descriptions! The level is roughly the back of the seat.

[SunSoaked]

Boom

[ItWillBeSlow]

Originally Posted by SunSoaked

Boom

Sweet setup. Is that fiberglass? What year truck?

[SunSoaked]

This setup takes commitment. You have to love high-end audio as much as you love the truck. That said, my 85 K20 is a restomod built to my liking. It's not a numbers matching truck and I'll never sell it.

Single cabs are limited in space, no way around it. Here's where the "blow-thru" design comes in. The sub box is mounted in the bed. You cut out the hole in the cab/bed and seal it with accordion boot. Now you can have all the bass/spl you want.

I've got a 12 inch sub, two Memphis amps (1050 watts rms), capacitor, audio control pre-amp, CD player and 8 component speakers in the doors/dash.

Ya, its pretty impressive. The clarity, power and ground shaking bass will rattle your teeth. I love it, wouldn't have it any other way.

[First c10]

Originally Posted by ItWillBeSlow

FirstC10 and 1971Stepside - I have a question for you guys, and anyone else with a similar box.

How did you build your floor for the box? Is it a piece of MDF resting on the rear "ridge" with some feet under it to support at the back? I have aftermarket cab mounts and an extra nut (original nutserts are stripped), so my cab bolts/nut extend above this ridge. This means I may need to raise my floor about 1" to clear the nut. I could double the bottom plate and cut a hole in the bottom one to clear, but wanted to see what you guys have done.

Regarding the clearance for the OE bench I started this thread for, it seems the back of the bench is basically a straight line from the rear seat bolt hole to the rear of the cab where the seat touches. I should have plenty of space with this sub (JL 10 TW1). I'm planning to offset it to the passenger side and use the driver side for storage.. i think.

Pictures probably do more justice than my descriptions! The level is roughly the back of the seat.

Hey iwbs! I got my cab bolted down and then I cut the remaining thread off. I did use MDF as a filler to get it above the gas tank valley and above the captured nut. You would just have to go a little higher/thicker. But I don’t see a problem with either set up! My seats were custom so I put my seats in and drew a line and that’s what I used as the thickness. That thickness is what I based what speaker I was going to use. Then I made up the correct air space by how wide I made the box.


1971step I like the red

Sunsoaked I remember committed to stereos..... back in the mini truck days cutting the back of the cab and front of the bed and putting a box for 4-12”. 15” etc. lol Looks cool and I bet it sounds good.

[1971Stepside]

FirstC10 and 1971Stepside - I have a question for you guys, and anyone else with a similar box.

How did you build your floor for the box? Is it a piece of MDF resting on the rear "ridge" with some feet under it to support at the back?

I had my cab mount bolts sticking up like that as well. Luckily, they cleared the bottom of the box. Yes, I put feet on the bottom to sit in the gap. Leave a 1/2" for carpet and padding.

[ItWillBeSlow]

Thanks for the replies everyone

[ItWillBeSlow]

Off to a decent start. Cant decide if I want to extend the back panel all the way to the edges, or cut in half and keep everything on the passenger side. 4' MDF is all I found locally so this is the draft for now.

[ItWillBeSlow]

Finished product