4th rebuild, 4th order bandpass bl 18's in expedition

[07_ZX10 4]

Well, i had subs up, port back in 2 different boxes, then walled and now got design done by robin for 4th order bandpass for 2 bl 18's. Took couple pics when building, will take some pics of all in truck tomorrow. Still got to put other front on, make trim panels and repaint inside of box. But i can do all that while its in the truck. I am using matt and fiberglass on all seams inside, has 1" rods inside, and adding all thread from side to side for extra bracing. Hopefully will be finished by tuesday. Still got lot left to do, but had to put in truck while i had the extra help to move it.

So far, just from playing around a little it sounds alot louder, has a total different bass, very deep. Will post updated pics later

[07_ZX10 4]

got inside box and matted and glassed inside today, gotta do some sanding and more painting inside. Waiting on suede to finish wrapping the other front to go on. Just from tuning a little more everyday, it sounds good on any music, it really picks up the lows alot better and sounds alot louder.

[shizzzon 461]

Kinda curious why u got rid of the wall. I'm not sayin bandpass isn't a bad choice, it should be more efficient actually but just curious.

If you were using the same subs, what kinda power did you have available?

I got a buddy that has a wall with basically the same sub, FI recones 2 18s doin 153s on 5kw or high 151s on music. His is tuned to peak at 36hz and capable of dropping to 18hz just fine.

His wall is ridiculously large, prob 20cuft or so.

[07_ZX10 4]

i had same amps ( 2 saz1500ds) in all setups, The 2nd box i had subs up, port up around 20 cubes tuned to 33hz sounded louder acutally than the wall did. The wall was 19.5 cubes tuned to 33hz also. I did a 150.? on tl with 3000 watts with ssubs up, port back setup. I never had the wall metered, and it sounded great also. I initially was goin to sale the 2 bls and get 4 ssd 18s and do a clam shell or 4th order wall. Our work got cut back to 32 hours, so gettin more wasnt option right now. I built 2 boxes for local guys in town and that paid for me to build new box, lol. So, i decided to try the 4th order with what i already have and be able to use my back window again. This box is like 4.5 sealed into like 19.5 or little more tuned to 48hz. And it picks up the lows alot better than any box before, sounds good on almost any music now. Hopefully will get metered next month at local show. I have to get new radio this week, i cant even play cd's now, unless i can find some tones onliine to try out.

[UpGradde 7]

Build looks excellent. Want to know why you decided on facing the subs towards the vented chamber? I heard that you're suppose to have the basket/motor part of the sub into the vented chamber, as well as keeping the subs away from the port/aeros whenever possible (you aren't suppose to see the sub through the port). Read that somewhere a while ago. Not saying I agree with it, Hell, you can see part of the mag of my sub through the aeros on my 4th order.

I'd like to know if there is any truth to that

Other than that, I had the same results as you when moving from a ported to a 4th order. Bass is very deep.

[Randal Johnson 544]

Is the port facing the back doors or the front of the truck/suv ??

Clean box build by the way ...

[BanginGMC 23]

Why didn't you decide to add the 45s? -- I didn't do it either on the last box i did, even though it was in the design. I didn't feel like doing it.. laziness i suppose.

Did you bolt the box to the bed? -- if not, are you going too?

Where are you planning on sueding? -- inside floor would look legit.

Do you like the 4th order better then the wall? -- have any pictures of that build, if so i'd appreciate it if you'd PM me some :popcorn:

Videos would be bomb

[07_ZX10 4]

i have 45s in the front section and have the others cut to go in, but like i said there was bout 5 people at my house so i got them to help me put in truck while i had help. I still climb thru the port to work now, i matted and glassed all tuesday and still need to get back in and do the other 2 45s.

Yes, its bolted to the truck with 8 bolts to where factory back seat was, and then has 6 or 8 3 inch screws with flat washers in the back area temporarily until i get under truckk again.

Inside the box will be sanded again and repainted white this weekend. The box was tripled on front layers, as soon as suede arrives the other front will b wrapped and put on, flush panel for amps will b wrapped also.

Out of all my boxes, this is by far my favorite. I dont have pics of the wall except for the design. I only had the wall in for a couple weeks and went back to subs up, port back.

[07_ZX10 4]

Build looks excellent. Want to know why you decided on facing the subs towards the vented chamber? I heard that you're suppose to have the basket/motor part of the sub into the vented chamber, as well as keeping the subs away from the port/aeros whenever possible (you aren't suppose to see the sub through the port). Read that somewhere a while ago. Not saying I agree with it, Hell, you can see part of the mag of my sub through the aeros on my 4th order.

I'd like to know if there is any truth to that

Other than that, I had the same results as you when moving from a ported to a 4th order. Bass is very deep.

I have never heard that about having the basket part needed to be turned to the port, maybe a 6th order or something. Almost every 4th order i have seen you could see the subs thru the port. The guy that designed it has done several 4th orders so it was built like he designed it.

[07_ZX10 4]

Is the port facing the back doors or the front of the truck/suv ??

Clean box build by the way ...

Its facing thru the front seats in an expedition. Guy that designed it said try it to the front and the back to see what i like best. I probably wont ever try to the back, cause i know it would b 10 times worse rattling to the back. Im happy with the sound now, just makin it look better, and thanks for the good comments

[BanginGMC 23]

How come you took the wall out so quickly?

[07_ZX10 4]

Got this design done, everybody told me they thought it would b louder and I was anxious to try it ou