I just bought 2 Fi SSD 12"d1's and the lmi seat lifters (or at least I think my order went thru.. their website kinda left me confused as to if my payment was actually made or not) ... so I am about to start building my box and I was wondering does your box have two separate chambers, or is it just one chamber and the subs share the air space?

anybody else feel free to chime in if you are familiar with his box and know the answer... i just know that alot of times his pm box gets pretty full so i thought this might be a more effective route for getting and answer.

 

99.9 percent sure its separate chambers.


Thats the only way I would do it FYI...

 

good call on those FI subs

 

bartak1 ... i agree, ive only built boxes with separate chambers ive never let two subs share the airspace... but we are working with very limited space... so i could use every cubic inch i can squeeze out of the box.... and also the shape is very abnormal... since it has to go around the seat bracket ... so i feel like it will be hard to determine where to put the divider so that they both see the same amount of airspace.

styxnpics... thanks, I'm excited to see what they can do. I was going to run a jbl1200.1 to them... giving them 600 rms a piece ... but they call for 800rms .. so i bought a hifonics bxi2006d (2000rms@1ohm), hopefully i can still manage some sq (its no zapco c2k 9.0)

 

I dont think Bryan's 10w7 box had a divider and I have no clue about the SI box.

Rowdy It took me quit abit of calculations to get the divider in the right position to give equal amouts of cuFT. Ended up with .95 per sub after sub displacement.

 

I hope the ssd does you well.. I plan on running 2 ssd18s ported myself. as far as the divider goes its usally reccomended however. you can get away without it. some need it more for bracing than anything. really its not gonna hurt anything untill you lose a sub. even then the blown sub will act more like a passive radiator in the worst case. I ran 2 8s ported for a while sharing a common chamber. you still might want to brace tho are you using 3/4 inch mdf?

 

No seperate chambers, only because of the odd shape and I couldn't get exact volume in both chambers. I wanted to use seperate chambers.

 

in what vehiclle ... your truck? ... i'd hate to think what those 18's will do to those undersized mirrors! ... haha only joking man ... honestly ... i just always read peaple givin you a hard time.

Yes 3/4in mdf.... Although, what do yall think of maybe having the bottom board 3/4" (this is downfiring just like brpink's current box) ... and then the rest 5/8" ....

 

brypink.... what was your box airspace before displacement? or i guess another way is asking what is the displacement on those mags?

The SSD's are .14ft^3 a piece. Thats why i thought maybe i will need to use 5/8" mdf for all the pieces except the bottom board (that supports the subs, which would be 3/4" mdf) to maybe squeeze a little more airspace out of the box

 

Woops, inserting foot in mouth now:o


With those SSD's I think Id make the whole box 3/4. Personally I wouldnt use 5/8th unless I was using some little little SQ woofer that doesnt have the ability to do any flexing.

My 2nd Gen Mags are .15 cu ft. displacement, I dont think the newwest Mags are any different. Of course Ive already been wrong once in this thread

 

Bartak1 ... thanks for the feedback... i'm sure that his mags have to be the same if not then very similar... and he was able to get 1.1 after displacement which I guess will have to be good enough and i'll just use 3/4" for the entire box.

I just noticed that they left out the Fi SSD in the 12" sub challenge on ROE for sealed portion of the tests... i hope that these are going to work in a sealed box

Also ... Have any of yall worked with polyfill before. I think optimal is like 1.5-1.6ft^3 for these subs. I have read that 1lb of poly is supposed to translate to the sub thinking it has 1cu ft more airspace. So with that theory ... yall think i should throw like a half pound per sub of polyfill in the box when it gets built?
I just am not familar at all with polyfill and its effects on the sound of the box as i have always been able to build my boxes to the optimal specs of the subs i have had.

 

No idea about the SSD in a sealed box. Guess youll find out

I dont use poly fill at all. I always heard to use a pound of poly fill per cu ft though...Now that I think about that it seems like a lot though...a pound of poly fill in a 1 cu ft box seems like it would be stuffing it like crazy...
Heck I dunno My mind is fried I think.

Its cheap, might as well try it with and without it...see what you like best, or if you can tell any difference.

 

Yea good call... i was just asking in case anybody had any experiences with it in the past or anything to see if it actually works. I will probably try with and without.

 

If you dont put it in the box you can always shove it down the port then blow it out...wont go to waste at all then.


Doh, your box is gonna be sealed. Lol woops.

 

I've put it in and out of my boxes, i personally like it without... What polyfill is supposed to do is to tease the sub to make it think that there is more airspace than there actually is. It seems to me that poly fill is mass correct? The more mass you add to an enclosed area the smaller the area becomes inside, i just dont see how adding more mass will add more airspace? Please correct me if im wrong because I have been curious about this for a while... I need to submit this theory to mythbusters...