Box Design For Rf T1s

[kryptonite]

So i'm gonna be building my new box for my Rockford Fosgate 12" T1s in a month or so (hopefully sooner if the weather warms up). Anyways, i've been doing alot of research, mainly on the forum lookin at different setups and such. So far the only definite things i know are that

it's going to be ported

i'm using 4 ga. power cable for speaker wire (overkill yes but never hurts)

i'm using bolts through the box instead of the cable through a hole

threaded rods will hold the box from flexing up and down, side to side and back and forth

and i'd like to do a removable port, one for daily and the other for competition

What i've been toying with is the idea of displacement and this is where i need someone to either prove or disprove my theory. I was thinking that since you want the enclosure to stay at a certain tuning frequency, you need to figure out the interior dimensions, obviously.

Now i was thinking that if you take the recommended enclosure volume, in my case it's 4.50 cu.ft. for both subs together. Than you take the displacement of the subs, bracing and the port (lets say the daily port) and add them all together and come up with 1.00 cu.ft. (hypothetically cause i dont have the numbers in front of me now) Could you add that 1.00 to the 4.50 and make the box 5.50 cu.ft. to make up for the displacement of everything to keep the tuning the same?

Or should i just build the box up to the 4.50 before displacement, make my port, put the bracing in and hope for the best?

I don't mind the extra work of figuring out the displacement of both ports and if need be putting in extra pieces of wood to make up for the displacement difference so that the tuning stays the same, i'm just wondering if i'm making too much work for myself?

PLEASE HELP!!!!

[Namosh]

Yes. If I am understanding you right, you add up all displacement and make the box that much bigger so it ends up at the size you are aiming for.

[kryptonite]

that's what i figured, but i don't know if it's worth the trouble, i'll have my written work on here later today hopefully so ya'll can glance it over and see if i'm doin it right. But i just don't want to do a ton of unneeded work

[lowrider77]

also how are u gonna fit 4ga to the T1 wen the bigger they accept 8 ga?

[Airborne]

I have 4ga in my RE's. Only trimmed a little off.

[kryptonite]

The T1s accept dual 8 gauge inputs so you can jump the voicecoil depending on your wiring. I'm just going to run a single run of 4 ga. from each terminal to a bolt in the side of the box that has a 4 ga. ring terminal on it. I'm pretty sure all i have to do is flatten out the 4 ga. a bit but if i need to trim it, so be it. I know i'm going to be trimming the 4 ga. to fit into my amp because the speaker outputs are only 8 ga. i'd run with some reducers but why pay for them when i can do it for free?

[kryptonite]

Here are the numbers i came up with for the different dimensions and such. I guess it could be a bit confusing so i'll try to answer any questions so that i can get as much help as possible. Like i said, i just want to make sure i'm not going to be jumping into more work than is necessary.

H= 15”

W= 36”

D= 22”

4.50 cu.ft. after port and subwoofer displacement

Single Port

Removable

Rockford Tune 40 hertz

12.25”x6”x8”

.7 cu.ft.

.86 cu.ft. with sub displacement

Daily Tune 29 hertz

13.05”x4”x6”

.5 cu.ft.

.66 cu.ft. with sub displacement

Competition Tune 50 hertz

5.78”x6”x8”

.33 cu.ft.

.49 cu.ft. with sub displacement

Subwoofer

Displacement: .16 cu.ft. both subwoofers combined

I'm pretty sure the dimensions listed above equal to 5.5 cu.ft. please correct me if i'm wrong. Now when i put the different ports in, with the combined displacement of the subs, i figure i'll cut different size chunks of mdf to make up the difference in displacement that will be bolted into the box. In theory, (atleast in my mind anyways) this should equal out the displacement and bring the box back to 4.5 cu.ft. and keep the tuning to that of which the port was built for.

Does this make sense?

[kryptonite]

Any thoughts on this? Anything at all?

[jsmoke222000]

RF_T1T2_subwoofer_boxes

LINK