BTW, it's very annoying when someone posts an image that wide directly on the forum. It forces the browser to have to scrolled horizontally to read the posts.
Let's get to some points that are important, and are being missed.
1) Published x-max rating of the JL8 W-7 is it's linear range; that is, it will have a very even BL curve(motor power) vs. excursion within this range. It's actual mechanical limit is in the range of somewhere at or after 25mm one way before it enters a danger zone. I have tested these drivers and confirmed these issues.
2) Do not plan to use this driver to 25Hz in a sealed cabinet. You waste it's output(you limit overall output by allowing it if you try to EQ it flat to 25Hz) and increase distortion in the process. Target an extension of no lower than 30-32Hz flat with E.Q. in a sealed cabinet with this driver for minimum distortion and maximum dynamic range/SPL ability. I actually recommend using a high pass filter to limit the power sent to the driver under 30Hz - this will insure excellent potential.
There is not even a reason to use as much volume as you have planned. Half a cubic volume net volume is sufficient, but you need to use a DSP crossover/E.Q. like the Behringer DCX2496 to optimize performance, however. Using such a device, you can flatten response, extend LF to a flat 30Hz and limit the output under 30Hz to maximum dynamic range and minimize distortion. One of these will approximate the output ability of a Velodyne DD-12, if you are familiar with that device.
If you want to do something impressive, use it in a slot port enclosure. You can get extreme output levels down to 25Hz this way. 110-115+ dB at 25Hz in room, corner loaded, should be the minimum possible with one of these in the proper slot ported cabinet design and driven with an amplifier of sufficient power.
Also, it looks like you plan to flush mount this driver. Please be aware that if you do this, design the front face level to screw or clip on. Due to the unique mounting method of the W7 drivers, it would be very difficult, if not impossible, to mount it in a recess that has very little room to the side of the W7's front edge. Either a very wide clearance to the side of the W7is needed in this recess, or you need to have the flush mounting method work by overlaying another layer that is removable.
-Chris
