Box for Two Diamond D6 15"
 

I am thinking about switching from a sealed to vented enclosure for my D615D2's. The box I am currently using is 48" on the front baffle, 44" on the back, 17" tall, and 14" deep with each driver seperated with a center brace of MDF. (Almost 5ft^3 before driver displacement I believe) Diamond audio recommends a box which is 3ft^3 with a vent 4" in diameter and 11" inches long, per driver. When I put this in WinISD the rear port velocity was very high, like over 40 m/s! Won't this create crazy port noise???

Anyway.... my question is can I simply place a vent this size in each chamber of my current box to create a box tuned at or below 30Hz with apx 2.3ft^3 per driver, and compensate for the smaller volume with some polyfill?


Here is a link to the T/S parameters and the recommended enclosures:

http://www.diamondaudio.com/products/pdfs/D6%20Woofer%20Tech%20Sheet2.pdf

I put the #s thru WINIsd, and at that small a box size, you'll need to use 2 4" vents about 13.1" long. This will get your port velocity down to .06mach, which should be OK....:smilie_da

Another option, if it will fit in your vehicle, is that 6cuft tuned to 30hz box on the spec sheet. Using 3/4" MDF with outside dims of 44"W X 17"H X 18.25"D, with a single slot port 15.5H X 2"W X 7.5" D will tune it to 30hz....:thumbsup:

Easy to build, and it should pound pretty good.....:smokin:

Unfortunately that depth is too large or I would definately have done it! My current sealed box is just about as big as I could cram into the trunk; I had to put it in first before mounting the subs (god help me if i need the spare....)


Just to clarify you are saying that each side of the current enclosure requires a 4" X 13" circular vent, or that the enclosure need four total, two on each side? Do I have to worry too much about having a smaller volume than Diamond recommends?

Thanks for your help, I am pretty excited about venting the subs. They sound alright now, I can't wait to hear them ported!

A couple more questions...

What is the equivelant to .06 mach in m/s ? When I input a 1000W signal into WinISD (for the 2 drivers 5ft^3, with the two 4"X13.1" vents) I get over 40m/s, according to the totorial on sounddomain this is almost double what it should be for a trunk enclosure.

Is the varible subsonic filter (15Hz or 30Hz) on my Alpine MRD-M1005 sufficent to prevent unloading the driver with this enclosure?

Is it realisitic to expect a 3db gain from porting my subs as WinISD predicts?