Im thinking about building a blow through box for my truck to run four 12s or four 15s.

Ive never done one before so im trying to find out some of the details to doing it before i jump in and do it.

1) I found most people use acordian seal from RV suppliers to seal up the hole inbetween the bed and cab. Is that the best thing to use ?

2) Water proofing the box how do you go about doing so ? I would perfer not to run a topper but i will if i have to.

3) i was thinking having 2 subs on each side facing in toward each other, were would the best spot for the ports be then ? In the front of each box into the cab with 2 smaller ports ? OR on the same side as the subs that creates a chamber to direct the sound to the cab through one big port ?


I will probably think of more to ask as this takes shape.

This is for my 97 sierra Single cab with an 8ft bed i would like to keep the box in front of the wheel wells so i can keep some space.

 

I've been working on a blowthrough for my truck. It will be my first time doing it, and I really don't know much about it, nor do I know anyone else that's done it. I am going to be doing four 12s. If you want to run it without a topper(what I'm doing it) you're going to either A)have a tool box or B)build your box, then fabricate a tool box type deal that is either flush with the top of the bed or lower(depending on how you build your box). I plan to go with B and use a spray on bedliner around the whole thing, including the box enclosure. On top of it being clean looking and completly waterproof, it's also secure as you would have to remove the seats to remove the box. Dynamatting the interior of the box enclosure may also be a good idea to prevent vibration, but I think the spray on bed liner will help with that.
Having subs face eachother usually causes cancellation, so that may not be a good idea. I am still looking for an efficent way to build the box, so don't ask me LOL. If anyone has any more information on this subject, PLEASE post as I know there are more people interested in doing this.

 

done several - now i would cut and bend the bed to the cab and weld it solid. seam seal it now it is tight, build box, coat it with resin & bed liner - now it is water tight! you dont even need a bed cover!

 

I don't have good build pics of the GMC Sierra Denali that is under the TR Members Install Pics under our shop forum-I am sorry. But, essentially you basically face the two subs towards each other with about a 6 inch chamber between them. Slot port the box vent to extend into the cab. Then you can use that accordian seal but it can be much smaller (we usually use about an 8" wide by 5 inch tall. You can get them from Topper King in Brandon custom made.

Best bet is to use a lid (new style ones are really nice), but we have also sprayed the bed/box out with Line-X. The only thing you have to watch with that is to get the box and the bed sprayed out individually. Then assemble it (should be obvious but I wanted to make sure you knew that). The Line-X does tighten up the bass significantly it seems. Do not dynamat the inside of the box-not necessary. You can fiberglass all the seams (or the complete interior of the box if you are feeling froggy) and that will give it another step to ward off moisture damage.

Blow through's are quick and easy. Not many clients go for them anymore but they sure as hell bang when completed. Take your time. Build out the box with the vent extension before you cut through the cab. Listen to it and see if it sounds right first. We use basically one design for everyone that we do and it always sounds good...

 

here you go we just put 5 layers of resin on the outside to watter proof it and did 2 layers + fiberglass matte in the seams this was done a few months agaio and has been rained on like 100+ times and still no problems









was just mocked up in the pics still had to final sand the edges and stuff











never took pics of it finished but like i sad we did 5 - 6 coats of resin on the outside filled all the screw heads with resin then sanded that with 220 and painted black.. also note the did all the cutting on the truck i didnt touch it.. he did that when he was 15

 

select products sells the rubber boot in 15ft sections.

 

i have done both ways - the boot always after years of use leaks!!!! tears, pulls back, - yes the bed moves seperate - but after it is welded it does not!, plus it looks a lot cleaner after it is welded, ground and painted. then you can do what ever you want. it cost about $1000 to cut, weld and build a box (4 12's or 4 15's), weather proof box.

 

yes i box it with heavy guage sheet metal.

 

iv have helped with a few blow thrus and we always have used the accordian seal, worked fine. im sure boxing the cab and bed together work, but i dont see it being any better.

 

i know what you are saying but have had much better success with welding, done over 20, and the last couple were welded much better finished project and never a problem, but those damn boots were a PIA, when they left the shop there great, dont know what the customer does to them they come back falling off torn, or leaking, I think they think (customer) there trucks are submarines. I would use the best silicone, inside the groove and on both sides of the out side, maybe the bass shakes them loose, IDK, they all were pretty big systems, 4 -15's, 6 15's, 8 15's, 4,6,8,12,16 12's , these were not getto systems!