I just built a box for my JL 12W3D4 and it slams SO hard. Its 2.5 cu.ft. with a slot port. We didnt do any calculations for it. The only calc. I did was 2.5 cu.ft. for a different speaker. The port was so spontaneous, it is 2in. wide and 10 in. deep, then it makes a 90 degree angle to the right of the box 20 in. long. It performs way better than I expected. It hits lows way deeper than the sealed 1.25 Q-logic box it was in. Man I am so happy right now. Just wanted to let yall know.
thats cool johnny. im happy for u. i started with struggling with systems since i was 16. i had an 88 sentra with 2 volfenhags max 1200 and a hammer series 1200 max. really crappy system. i have maybe spent over 4000 dollars with trade ins so i can upgrade lil by lil. now i got an alright setup but cannot get the box right. i got a 96 firebird. camaro boxes suck. i dunno where to start. right now i tilted the box for a camaro to be able to face the magnets to the front of the car, two 1206t. i need a box man-----recommendations please. i cant bump anything with 1.2 cu volume.!!!!!
Hey, anonymous, did you do math to find that, because I was wondering what is was tuned to. Thanks for the input. And for Elecgenius, I dont know, this was the second box for me and my friends. We've only built a 8.5 cu.ft. box for my friend's L7 15, it slams by the way. I know what you mean about struggling with sound, Im still trying to get it right. I need a new HU and a new amp or amps.
A 2x10" slot port in 2.5 ft^3 would need to have a total length(measured throught the center) of about 29" for a 25 Hz tuning frequency(winISD).
With a total length(the whole "L" shape) of 20" you get about a 29.5 Hz tuning frequency.
This doesn't take into account your actual internal volume which is the gross internal volume minus speaker and port displacements. The actual tuning frequency is going to be higher with less volume.
the port length is 10 in. then the other part of it is another 20 in. thats 30 in. isnt it? So that would be about 25 hertz like yall said, right? I dont know all the specs like speaker vol.Thanks Fishy.
be very careful tuning a box that low. if ya tune the box lower than the Fs of the driver itself, you run a good risk of loss of damping and driver damage.
Jurassic Lunch kinda stuff. Low tunes work very well on ID Maxes, fs of 20.2 hz . I'm considering porting mine if I can squeek the volume into the console, tune around 26-28 hz.
He's probably ok. The fs of a 12w3d4 is about 26 Hz.
I've got my 10w3d2's playing in a JL "purist" enclosure which is tuned right at their fs at 28.8 Hz. I tried a much larger "flat" enclosure "recommended" by winISD which was tuned at about 24.5. They sounded great at low volumes but like Glass said had a tendency to "unload" if I pushed them much.
I often wondered why when I measured the dimensions on my custom built "purist" box the tuning came out to nearly exactly 28.8 Hz.
gives me encouragement from what im reading here with the box experiment im working with koz on for his 12 inch earthquake tremors (the length of the ports is what im focusing on)
hey I just put a different speaker in with fs of 35 Hz. What will happen? Im just curious, i plan to put the JL back in, they sound pretty much alike. I did notice that my amp runs extremely hot now that I built the ported box and put the new sub in. It turned off after only about 40 min. of play with volume at 15, vol goes to 34. Should I be conserned, its a punch 150s pushing a 400w rms peak 800w sub. It only cut once before with the JL sub after about an hour of slamming. Whats the matter?
It shouldn't affect the amp, but if anything, I'd guess that because the sub has better cooling due to more airflow to the voice coil, the coil isn't getting as hot, which means the impedance of the coil isn't as high as it would be if it were in a sealed box. Heat rises impedance. Thus, since the amp is seeing a lower impedance, it may cause it to head up a bit more.
