Need a Sub Enclosure for a 21FT Formula (Cuddy Cabin) LOTS of room to work with!

[illtww]

First off let me start by saying how much I am in AWE of some of these subwoffer projects. The "CRAP" you buy at local car audio shops cant TOUCH this stuff! I am totally pumped and have my wood-working buddy pumped about building a couple of these cabinets for car and home use!!

But first want to start out with something simple for my boat. (Tappered Horn possibly!?!) I don't have to hit 130db... Just louder than the standard sealed Circuit City box.

Here is what I am working with:
21FT Formula Cuddy Cabin. (can work with the whole cabbin but also store stuff in there like the 3 batteries that power the system, noodles etc...)

Equipment List:
I have 2 polk MOMO mm2124: (will these work)
MM2124 Car Subwoofer from Polk Audio

1 SPL Z2x-820 Amp (pushes the crap outta my old 12" momo)
2 X 180 RMS 4 Ohm, 2 X 230 RMS 2 Ohm
1 X 460 RMS 4 Ohm, 820 Watts Max Power

Running a Pioneer Premier deck that can set the crossover freq for the
subs mids highs etc...

Mids and High's:
8 Polk MM651um (4 on tower 4 in boat)
MM651UM Car Audio Speaker from Polk Audio

Space I am working with:
I dont know the EXACT dimensions because the boat is not near me but it is a pretty larger space. (I am including pictures) I would ideally like to place the sub-box on ones side of the cabin or lay it on the side of the boat to maximize space for some other things but I am open to suggestions!

My buddy that is in the pic is 6ft tall so I am guessing the cabin is around 72 inches from the tip of the boat to the cabin door.

Side note:
People come out on the laker here in NC with ******* DJ speakers attached to the speaker bars. (full on 15's and 12's and generators etc!) While I am on a very limited budget since I have no job right now I still kinda want to show them what my lil 22ft boat can pound out!) (David vs Goliath mentality)

This is EXACTLY what my boat looked like when i got it. (took us 3 months of working on it!!!)
1980 FORMULA THUNDERBIRD 21FT : eBay Motors (item 250608782492 end time Apr-03-10 04:38:02 PDT)


I can guarantee you that i will have pics of 20something girls as well on my boat. I am looking forward to what u "MAD SCIENTISTS" come up with!

Travis

[illtww]

Was also thinking the autotuba but I really likt the Tappeered Horn that Justint built for his Supra on here. Just need some help sizing one for my cabin.

[bjorno]

Originally Posted by illtww

Was also thinking the autotuba but I really likt the Tappeered Horn that Justint built for his Supra on here. Just need some help sizing one for my cabin.

Hi illtww,

Not sure if a TH is a good use of the Polk-MOMO driver but if put into a T-TQWT:

You don't need to EQ the sub, (except for a mandatory HP filter at the low FR end) or time delay the mains with external electronics as you need for many TH designs.

+ The fact (IME) that the box is totally omni in the pass band and stuffed like a TL, i.e. if properly internally braced no hollow boxy woody sounds will ever be heard at close listening distances.

The T-TQWT delivers high SQ even if blocking the terminus front leaving just a couple of inches of area for the bass escape from.

b

[illtww]

Bjorno,

Thanks for the reply! I am open to using some kicker drivers if they are a better fit. (I know a kicker dealer) What are the dimensions on that box u used in the simulation. is a T-TQWT much more complicated than a TH to build?

thanks again. WIll prb start building it next week!

[illtww]

Just did a few calculations. This box is 10 feet long?

[bjorno]

Yes it's 10 feet long and should be folded at least once.The volume is about 4.47 cu ft .

b

[illtww]

is there anyway to get a box that is no longer than 5 feet long and put it on one side of the cabin? (like the right side)

I prb need some exact measurements so you guys know what I am working with I am guessing!?

[sumaudioguy]

Parts-Express.com:Eminence Sigma Pro-18A-2 18" Cast Frame Driver | sigma pro-18a subwoofer 18" subwoofer pa subwoofer 18" driver

This sub works in about 8 cubic feet so you could use 2 of them with twice the cabinet size. You will probably want to water proof the cones for use in boat or you will have "muddy bass" haha. One should make 120dB in a sealed box at 40Hz with about 200 watts of power. Two of them would be even louder but not go lower. I always use EQ to roll off extreme lows and flatten the bottom end. If you do not brace up your "cabinet" you will probably find a lot of leaks and buzzes after cranking it for a while.

Good luck

[bjorno]

Originally Posted by illtww

is there anyway to get a box that is no longer than 5 feet long and put it on one side of the cabin? (like the right side)

I prb need some exact measurements so you guys know what I am working with I am guessing!?

Hi illtww,

5' is ok including 3/4” Plywood thickness. Best to take measurements at your chosen site before starting the build of the bass coffin, if to large to put in you boat, you may have to consider placing it in a dinghy.

b

[Brian Steele]

Originally Posted by bjorno

Hi illtww,

5' is ok including 3/4” Plywood thickness. Best to take measurements at your chosen site before starting the build of the bass coffin, if to large to put in you boat, you may have to consider placing it in a dinghy.

b

If you design it right, you can build it in two sections that can be bolted together when mounted in the boat.