whats going on with the audio forums these days...this is the only forum i could actually get good ideas from nowadays...it just takes a while cause we dont have a lot of traffic here. example...i ask a winisd question so i can fab my own sub box for the dimensions of my trunk in my new car...and i get several... "dont build your own boxes, buy a JL H.O. wedge box it will sound better than anything you could build..." Yea sure what is with these people... anyways ill toss this ? out at you guys... in my car, i plan on doing 2 13w7s i am going to build both ported and sealed boxes...whats this EBP on winisd mean?? because my W7s dont model up higher than the middle of this "EBP" does that mean they shouldnt be run ported? thanks guys, trying to get a rough idea for internal volume id need for a flat curve in both sealed and ported. calculating port size, if square ports are better than round etc etc. -Mike-
I am no expert, but i was under the impression the HO JL boxes are HO because they are ported. That is true for the 15W3 anyways, there is a nice big port between the red part and the rest of the box. As far as the W7's go, JL reccommends a 2.35cu. ft ported box tuned to 30Hz, with the range being 2.0-2.75 and a simple slot port. Their dimensions in inches, off thier site are: W 25.25 H 17.25 D 16.5 Internal slot width 2.0 Internal slot Height 15.75 Internal slot Length 25.375 Internal port Extension Lenght 8.875 Front Baffle Thickness 1.0 Wall Thickness .75 Also, what amp are you using? In my experience the W7's kinda suck....too much space and power needed to make them do anything, although i have never used a properly calibrated JL amp to drive one....just wonder how much difference that will make. At http://www.jlaudio.com/subwoofers/pdfs/W7_DS.pdf they have detalied settings for the amp. I tend to take the engineers opinions on things over my own. Anyways...that may or may not have helped, but its my .02 h34r:
EBP is simply a measurement enclosure builders use to assist in selecting enclosure type. Those who use it typically go with over 48 to 56 as leaning more to ported enclosures, with those #s in between being subjective. Below these #s leaning more toward a sealed enclosure. Other enclosure designers will use Qts as their indicator. The general consenus being from .40-.50 and higher being sealed (again, those inbetween being strictly up to builder/customer preferance, and under being ported. I personally prefer to use Qts as my indicator, as my belief is the overall strength of the woofer (including suspension compliance, which I believe affects it's overall performance and is included in the equasion to arrive at Qts) should be the determining factor in the drivers application. The flat BL curves indicative of the supersubs however, really allows for more cone controll and strength further into their excursion and really leaves them happy in both ported or sealed enclosures IMHO. Why? Well, their controll and strength so far into the excursion allows them to be considerably more stable when compressing so much more presurized air as in ported apps (as twice the pressure develops in ported enclosures). Now, in the case of ported application for your driver. I modeled up with 1000 watts per sub and still came out safe, so I will suggest a general enclosure design for you. about 5 feet tuned to 21Hz (10H X 3.5W X 37L on the port providing 30 inches of area **edit, what a dumbass, I mean 35 inches of port**) per sub looks flat and strong. As for sealed, I need to know what power you are planning on using. I like as big a box as possible with the alotted power to really show off the woofers SQ and get the most out of it as far as SPL.
Size is an issue, but power isn't. I'm sending my 10w7 250w from the rear channels of a Tru t4.65 and its plenty loud for me. The box is around 1.7-1.8 cu ft sealed though.
More actually, those measurements are without port and woofer displacement. I figure about 7 feet total per sub. That is one of the main reasons why I chose the Brahma over the W7. But, I am glad I chose the Brahma as it is more transparent than the W7 installs I have heard... even with almost twice the power.
Looks Like Sealed It Is!!!!!!! there is no way in hell im putting a box that size into my new car...if it was the cougar then maybe...but frig that. -Mike
