Box for four tens.

[Spkrman]

Your in a trunk - rule of thumb is tune the box about 5hz higher than you want... the acoustics of the trunk will take care of the rest.

I'd give it 80 sq inches of port, no L.

Depending on how the box fits in your trunk, it would work a little better.

 

[brandontw 10+ year member]

i dont really have room for 80 inches, cause it would have to be a really long port, and i would be losing mondo airspace insode my box

 

[brandontw 10+ year member]

oh, and im going for as much sQ as i can get, so tuning for 32 hz, will be about right for me i think

 

[Spkrman]

I think you missed my point - tuning the box to 32hz will actually tune somewhat lower because your in a trunk... typicaly 3-10hz... the less airflow you have back to the front, the lower the trunk will tune your box.

 

[brandontw 10+ year member]

yeah, and if im tunign for sq it should be 25-30 or so , so if its tuned to 30, then dropped 5 by the trunk, then that will put me at ~27hz, so that is about right.

i got your point, i might tune it up a little higher though

 

[brandontw 10+ year member]

well, i didnt have the funds for the wood this weekend, so i will have to wait till payday to commence constructio, so any last minute tips would be great, should the port really be 80 inches, like skrman said, and if i cant make my box bigger, then how will the port taking that much of my airspace work out? cause it would have to be like 13.5X6!! to get 80 inches, and that would mean the port would have to be like 34 inches long for tuning at 35Hz

that would take up1.59 cubic feet, and my subs take up like .45, so that would make my box like 3 cubes after displacement, and that is too small i think., so what do you think?

 

[DBfan187 5,000+ posts]

I think you should build your box inside your trunk. Fiberglass, ever use it?

 

[theCybe 5,000+ posts]

I've been spying on this thread, because I also ordered 4 of those.

I've never used fiberglass; Where to start?

My box design is still up in the air. I'll post more on that, later tonight.

Which amp have you chosen for those 4, Brandon? Running stereo or mono?

 

[Spkrman]

well, i didnt have the funds for the wood this weekend, so i will have to wait till payday to commence constructio, so any last minute tips would be great, should the port really be 80 inches, like skrman said, and if i cant make my box bigger, then how will the port taking that much of my airspace work out? cause it would have to be like 13.5X6!! to get 80 inches, and that would mean the port would have to be like 34 inches long for tuning at 35Hz
that would take up1.59 cubic feet, and my subs take up like .45, so that would make my box like 3 cubes after displacement, and that is too small i think., so what do you think?

Don't make the port that long.

Start with that much area and a port that goes straight back, no L.

If it doesnt hit low enough for ya, you can always block off port to tune lower... but if you short your port area, its very difficult to add more.

Or at least thats the train of thought of an SPL'er //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[analogkid]

brandon,in the beginning of this thread i read you were going to wire all 4 to 1 ohm. these are single 4 coil subs. how would one do that? just asking cause i got 4 also.

 

[Spkrman]

brandon,in the beginning of this thread i read you were going to wire all 4 to 1 ohm. these are single 4 coil subs. how would one do that? just asking cause i got 4 also.

simple, everything in parralel.

 

[analogkid]

that dosen't take it to .5 ohm? i always thought if you parallel two 4's you get 2 ohm, add in another you get 1ohm, 1 more and it goes down to .5ohm. i guess this is basic crap i never learned. how does it really work?....or was it 3 would make 1.66ohm and the fourth would take it to 1 ohm?

 

[Spkrman]

that dosen't take it to .5 ohm? i always thought if you parallel two 4's you get 2 ohm, add in another you get 1ohm, 1 more and it goes down to .5ohm. i guess this is basic crap i never learned. how does it really work?....or was it 3 would make 1.66ohm and the fourth would take it to 1 ohm?

1/(1/r1 + 1/r2.....)

It actually goes 2 4 ohm parallel = 2 ohms, 3 = 1.3333... ohms, 4 = 1 ohm.

 

[brandontw 10+ year member]

I think you should build your box inside your trunk. Fiberglass, ever use it?

nope i havent, it sounds hard, and expensive, and i need my box semi removable too.

 

[brandontw 10+ year member]

Don't make the port that long.
Start with that much area and a port that goes straight back, no L.

If it doesnt hit low enough for ya, you can always block off port to tune lower... but if you short your port area, its very difficult to add more.

Or at least thats the train of thought of an SPL'er //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

so.. i dont need it to hit extremely hard, im not competing, and my car is already falling apart, so extreme spl will just further tear it apart, and any 4 subs with 1500RMS going to them will be plenty loud for me i think, considering my 2-12s with 600rms was damm loud, and i still want to retain sq, so will my current 54 sq inches of port work ok?, and like i said, what about the airspace i lose increasing my port area, im already pushing it with my current port, i need around 4 cubes after displacement