scooter99

Ok here it is. I changed it up. I couldn't get a 45hz tune with that design. Not enough room to widen the port. But I did some rearranging and this is where I'm at! I think this is gonna work and I'm excited about it. Torres calcs Sealed Ported Total with port Here's the design. I basically just rotated the sealed chambers to the sides and I get more ported and the ability to widen the port. Now the only question is, do I give myself more sealed area and mount the subs with the motor into the ported section, it gives me .36 cu ft more for both sealed chambers. But it also takes .72 cu ft away from the ported chambers. What do you guys think?

Ok scratch that i can get more out but im gonna have to switch the format a bit. Ill have to rotate the subs to the sides and the middle will be the pirted section. Im at dinner but ill work on a design tonight. Ill aim for 45hz, but whats the lowest i should be at if i cant get to 45hz?

Hmm so what happens if I can't get it up to 45? I'm having problems getting it even to 40 hz. I'm at 37 now. I don't think I can budge at all in the width cause I've only got a quarter inch or so between the subs as it is. I'll play with it but I'm not so sure about getting it up anymore!

Thanks. Me too! Hopefully ill be able to get on it sooner rather than later!

Ok thanks guys. I'll tune it higher and get to building! Build log is in my sig if you all wanna follow along! Again, thanks!!

Hey guys, what about tuning? Is the tuning ok or should it be higher?

Wait should or shouldn't?

Ok edited the original post to tell about the bracing rods as well as add the pictures of the amps and amp rack.

Sorry guys, I also plan on bracing it with all thread and nuts. I'm sure the back wall would flex quite a bit given the length of it. I just didn't picture the bracing, probably should've put that in there. I'll edit it now.

Ummm yes! It's basically a box that will be built to fit in the tool box. The tool box is cause I don't have a tonneau cover or a shell. This will keep things locked up, and weather proof. People will think it's just a tool box from the outside. Plus it sits below the bed rails so it's hardly seen from the street. So it'll be a box within a box.

It's pretty heavy gauge steel. I'd honestly say it's about 3/16 to 1/4" thick. Ok maybe not 1/4" but it's a toughly built box. I'd hate to cut a side off, BUT I'll DO IT DAMN IT! I'm just being silly now! Sorry guys, I'm in love with my design and I want it to work!

I do agree, and my plan for that is to deaden the inside of it before anything goes in. Hopefully that'll help. As for the subs, yes, there's 13" from the front of the sealed sections, where the subs screw into, and the upper lip of the box lid. The subs are only 6.75" deep if I remember correctly, hold please while I look that up........................ Que jeopardy music...............................What is 6.75"? THat is correct! So yes plenty of space to put the subs in, even with my big ass body. And they won't be screw in, but allen head bolts into threaded inserts. So that will help for sure. Also my plan is to make this out of birch instead of MDF cause it would probably only be my ass to be able to get it in and out of there. I can see the conversation with my wife now, "honey can you help me take the box out of the truck?" Her- "I don't think so, you're the dumb ass who decided to put subs in there and make it heavy. You do it!" You guys think I'm playing don't you!?! Plus the box doesn't just slide through the bed. I have to lift it up and over the wheel wells and down. It does slide between the bed rails up and over the wells so that's a good thing but it is a pain in the ass, and back, if you do it full and by yourself. So lighter the better. Also another reason to keep the port removable so I know for sure it slides right into place with no problems.

Those are all good points. I'm not so worried about degree of difficulty, honestly, I'm not planning to do this over and over again. So I'll be happy to take my time with it and get it in and done. I'm not worried about straight sides etc either. I'll make sure the wood is straight even if the box is not. I do have to figure out how to secure it to the box itself but we'll see how it all works. If I knew how to GOD DAMN WELD, I'd just cut the side out on the cabin side, build the box, slide that bitch in, and then weld it back on. Maybe I could do that anyway and instead of welding it, screw it back on and silicone the seams. I am planning to truck bed line it anyway. So maybe I can use some polyurethane or something weather proof and then smooth it out and spray it. Should be good I'd think. Aside of the degree of difficulty, what do you think about the design part? That's what I'm most concerned about.

You really shouldn't tap into another line that large. If you have the room in your box it's not that hard to run another dedicated line. Trust me if you ever have your dryer going and that compressor kicks on, you're almost always going to trip that breaker. I'm not a licensed electrician by trade, but I have my contractors license. If you want help doing it let me know and I'll see what my schedule is like to come check it out. But just from experience, you should really run a dedicated line for that. You'll be much better off in the long run.

Why do you say that?

So here's the deal. I've already got a plan for subs and a blow through. I have a design that will do a slot port through the cabin tuned to 34 hz and that would be fine. But I wanted to see if I could do a 4th order on it. What I have is a truck box that I'm going to enclose it all in. That's been the plan all along. What I don't want to do is cut the entire back wall of my truck out, which is basically what it's going to take to do it. So I thought i'd brainstorm a 4th order to be contained in this box. That way I only have to cut out the port area and it will save me some strength and integrity of the cabin and bed walls. **Higher tuned better design on page 2** Some history and data Truck: 1994 Ford F350 Crew Cab w/ 8ft bed Subs: 4 - DC Audio Level 4 12's (recommended 1cu ft sealed / 1.5 cu ft ported) Power: 2 - Soundstream Rubicon RUB1.2500D's Truck Box Dimensions: 64" wide x 29" deep x 18" tall There is a 2 inch lip above the 18" box, that's what the lid goes over. This is relevant for the design, you'll see below. Pics of the box: In the truck Now onto the design I did. This was just a quickie in sketchup I did today. Here are the torres numbers First is sealed - The sealed chambers are split in two. So the Torres calcs you see need to be multiplied by two to give you the total. But in breakdown, EDIT: I had the displacement wrong and only for one sub. So the actual on this is .36 for displacement. So instead of it being 2.40 total like I thought it's only 2.22 per side which is only about 1.1 per sub. So not as much to play with as I thought. Next up is the Ported Calcs. This was just the area, not including the port itself, and maybe that's not the way it's done. However when you see the design below you'll see why I did that. That being said, I am still learning so that's why I posted this up so I can be corrected. Ported section totals 9.70 cu ft which breaks down to 2.425 cu ft per sub. Now the ported. I don't know how to do the ported sections on a 4th order. I thought it was the ported section you calculate, not sealed, and then I thought I read somewhere or was told by someone you do the whole enclosure, sealed and ported sections together to figure it out. I don't know but this is what I came up with. Between the sealed sections (remember they're divided) I end up with a max of 9.5" wide. Then the height is at 16.5" tall. So I did torres on the whole enclosure specs, and put that in and got 34.89 hz with it being 15" long. 3 of those inches are external. So I'm not sure if that's done right or not but again, that's why I posted this to find out and learn. Onto the sketchup designs. This is what you'd see if you were looking from the tail gate into the truck bed. Minus the actual truck box of course. The part on top, is a 3/4" piece of acrylic or plexi glass. That's where that lip on the box itself comes in handy. Cause that can go in that and just sit on top of the box so to speak. Obviously it has to be sealed etc, but I think you get the idea. Back areal view. You can see the separated sealed compartments here. The sub motors will go into the sealed sections and the cones will face the ported back sections. Front cabin areal view Front Port view - this is where I was trying to get to. The port area is basically all that will be cut through the rear cabin wall and the truck bed wall. Forgot to mention also, I'll be bracing it with all thread and nuts. I didn't know how to show that on sketch up. Also this is what it'll look like inside the cabin with the amps. So there it is, my design. Now my biggest question is, will it work? If not what's wrong with it, what should be changed, etc? Thanks guys for any help. I don't know much, if anything at all, about 4th orders other than what i've seen on here and around the net. So I'm hoping to learn something from this. I'm not in a huge rush to build at the moment, god knows I have my hands full already with the rest of the vehicle. But I'd like to get a design nailed down so I know what direction to go when it is time ti get started.

I was going to do this in my civic, and the only thing that I was questioning, was if you run a duct into your sealed trunk, from the other sealed side, won't that cause a breach in the seal so to speak. I mean the duct is sealed so I guess not but I just couldn't really wrap my head around it. But seems like this would be the best case for cooling I think. Might want to encase your amps though. Then the cool air would be directed at them not just into the trunk. Or you could direct under them and that would help too I think.

Just wondering, but if weight was an issue, why not use Birch instead of MDF? There's a big difference in weight between the two isn't there? Or not enough in the trunk to matter? Nice work buddy! Can't wait to stop by one day and check this thing out when it's done, when you're not busy of course lol! Seem to always catch you on a busy day! One day you'll be just hanging out and I'll get to hear the hoe and the lex on the same day!

My only question is, was there a reason you used hex head bolts kn the plexi vs some nicer allen head screws or something with a better finish? Just wondering! Its your ride, badddd ass one too, i just think the other screws would gove it a better finished look cosmetically. The box looks sick as hell and i for one would love to hear it one day, along with the tahoe! Keep it up Steve

My inexperience asking here, but wouldn't the port not lining up with the ski hole / pass through, cause problems with air flow?

So maybe this is a stupid question steve, but when you say isolated, are you going to seal off the sub facing the seat forcing the air through the rear seat pass thru and then a port in the deck? Trying to understand, considering what we talked about at the shop the other day, you're making me reconsider what I was telling you I wanted to do. Can you shed some light for me please? I guess I could just wait and see the rest of what you do today!