SSD12 Build

[krazykid]

I just spent about an hour messing with WINISD and got some decent results I think.

3.2 ft^3
18 Hz tune
2 4" round ports. 63" lenght, 107Hz port res.

I need a small-ish box. Idea is inverted mounting, with the basket out, gaining about .15 cubes, and looking cool as well. Up fireing, sub mounted on the bottom of the box, with aluminum legs holding the box off the base. Ports in the front.

I will upload the WINISD info tonight. but until then...

Transfer curve is about a 3.5db. -4db around 18hz to -.5db around 50hz.

700W input:
108db 18hz
109db 22hz
111db 30hz
112db 50hz

16hz & 27hz are the peak XMAX (21mm) for the speaker.

15.2hz is the peak of 26m/s for port speed. ave port speed is around 20-21

600W input will give me about 2mm less excursion and port speed drops to 24m/s max. and I only loose about 1-1.5db SPL across the board.


What do you think?

[Mike P.]

Your numbers are right. The ports displace .9 cu.ft. so the total internal volume needs to be 4.1 cu.ft. A 21 inch cube is 4.3 cu.ft. internal. Getting the ports in there will be fun! Remember that when using elbows the port length is determined through the center of the port. Post a build thread if you can.

[Fi Audio]

Like Mike P said... those ports will be fun to get in there.
Should make for a solid little HT setup. What dims are you looking to do for the enclosure?

Thanks,
Scott

[krazykid]

note sure... I will work on that today tonight. I could always do a slot port if the tubes will be too hard to snake in there.

good news... I won a EP2500 for $220 on ebay. Ill order the speaker when the check clears from my side job... aka wife doesnt see this money.

[krazykid]

hang on a sec... 63" that is 31.5" long PER port right... lol

Slot port:
3X10
72.42" long

It would make a few 90deg bends but it would be easier.

[Mike P.]

No, that's 63 inches long for each port. A slot port 3" x 8" x 58" long would work as well. Air speed would be under 28 m/s with 700 watts input power. If you go with a slot port make sure to round over each end of the port as well as any corners.

[krazykid]

Yeah I know it was per port... I was joking about shoe-horning these into the box.

I am looking at a 20"X20" by 22" high box. This will net me 4.02 cubic feet. (both 63" ports are .88 total and I am going for 3.2 cubic feet for the box) Remember I am inverting the woofer so I will save the .14 for the basket and motor.

I have to look at how tall a 4" X 63" long port with all the bends will be.

If the 4" dia 90 deg elbows are 4" high... I can make a 64" port in 3 straight legs and 2 180 deg elbows.... which will be around 18" tall or so... Minus flairs. it is close.

[Ricci]

That's a lot of port. GL! I think that a slot vent may be easier. Actually how are your fabrication skills? You could try to use the power port design on it, to cut the vent length down.

[krazykid]

I got mad skillz Y0!

No really, I can do anything... but I never heard of a powe port design. Google gave me this: http://www.htguide.com/forum/showthread.php4?t=22953 do you have anymore info?

[Mike P.]

Post #16 will give you an idea of what is involved with a power port.

http://www.hometheatershack.com/forums/funky-waves/10524-custom-re-xxx-subwoofer-build.html