I'm going to build a MDF and fiberglass enclosure for an IDMAX V3 D2 I picked up used. The enclosure is going in the trunk of my Mustang convertible and I would like to port it, to get a bit more SPL. I'm currently running a IDQ 12 V3 in a 0.8 cube net sealed box. I like the sound but when my top is down I get a pretty significant reduction in cabin gain.
Anyway, I mocked up a cardboard baffle yesterday and did some measuring. With the fiberglass enclosure conforming to the available space I should be able to net 1.75 cubic feet after allowing for driver displacement and port displacement.
When I model in WinISD, it looks like I can tune to 31 Hz, with a 1.5" X 7.25" X 15.3" slot port. That gives me 2" of clearance from the rear of the port to the inner wall of the enclosure. I plan to get the exact volume by filling with rice or something before finalizing the port length.
Here is where I have questions though. I would expect some audible huff from my port but the enclosure will be in my trunk so I don't really care about that. So, is there any issue with my port height and width other than huffing which I won't be able to hear?
I'm running a RF 3Sixty.3 so I can flatten the response hump out with PEQ but I don't know if there will be audible problems from the somewhat small enclosure size. I have a reasonable understanding of what QTC does to the sound of a sealed box but WinISD doesn't give QTC for ported boxes. Is there something else I should be looking at to see if I'll be over or under damped? Should I consider using some acousta stuff?
FIY, the Image Dynamics web site gives you the wrong PDF if you try to download specs for the IDMAX 12 V3 sub. I found a copy of the right specs and the parameters are below.
Thanks a whole lot in advance for any help.
IMP 1 / 4ohms Nominal Impedance
Re .7/ 2.8 Ohms DC Resistance
Fs 20.2 Hz Resonant frequency
Qes .424 Electrical“Q”
Qms 2.05 Mechanical“Q”
Qts .350 Total“Q”
Vas 5.71 cuft (162 liters) Equivalent volume
Xmax 24.6mm Onewaylinear
Sd 545 cm2 ConeArea
Spl 93.2dB/88.1dB 1wt/1mG.P. / S PLi
Pwr 1000 RMS POWER