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Building a pair of new Boxes for a small hatchback and want to try 4th order with a single 8" internal driver with 8" passive radiators used in place of the ports in each box as this will result in a better bandpass match with the satilites, and I have a few questions....
I did some research and I think I'd be better off with a 4th order bandpass.
I'm using a pair of Dayton Audio SD215-88 DVC drivers matched with a pair of Dayton Audio SD215-PR Passives, both have a Vas of 1.4 cu. Ft.
Using AJDesigner, I substituted the PRs Sd for the dia. of the ports, and I got the following results:
Vf=1034.21 cu. in. Vr=1714.82 cu. in. Fb=53.49Hz Fl=32.93Hz Fh=86.89Hz
These figures go well with the 4 ch speakers that will be at the 4 corners in the car. my best estimates give me a box that has internal dimensions of 10x22.5x8 inches for the rear sealed chamber with the driver in it, and 10x22.5x5 5/8 for the front chamber with the two Passive radiators.
I will be using acoustistuff to dampen internally. I've included the vol. of the driver and passives in my calculations with a 10% increase is box size due to the damping material. The boxes will be internally braced in both chambers but how accurate do I need to be in building the box?
Since the box is over-sized, can I build something close and tune it with wood blocks in the rear chamber to get the right volume and mass on the Passive radiators to tune them?
Am I missing some other things that need to be included in the calculations?
I have a size restraint that says that both boxes have to fit in a space that is 12 in high and 48 wide, so I have to increase/decrease the depth to get a size I can work with. I have up to about 18 in to work with.
Posts: 4 | From: Columbus OH | Registered: Oct 2009
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