does this all make sence?

[splescort 10+ year member]

hdc315 copper

28" w

21" h

20" d

port 19.5" x 4" = 78sqinch

total port length 22"

tuned to 39.78 hz

cuft 4.53 before sub displacement

cut list

top 28x20

bottom 28x20

left side 19.25x18.5

right side 19.5x18.5

back 28x19.5

front 23.35x19.5

port 14.5x19.5

gonna power with 1500rms

going to do sub up and port back

Click to read more...

 

[Kangaroux 5,000+ posts]

You got a diagram we can go off of? Maybe it's just me cause I'm lazy but that's gonna take a while to check lol

 

[splescort 10+ year member]

cant say i do, its all on the back of a napkin kinda drawing

 

[hispls 5,000+ posts]

hdc315 copper28" w

21" h

20" d

port 19.5" x 4" = 78sqinch

total port length 22"

tuned to 39.78 hz

cuft 4.53 before sub displacement

cut list

top 28x20

bottom 28x20

left side 19.25x18.5

right side 19.5x18.5

back 28x19.5

front 23.35x19.5

port 14.5x19.5

gonna power with 1500rms

going to do sub up and port back

Seems like a lot of port area. If those are the outer dimensions of the box you'll be down to more like 3 cube net with sub/wood/bracing/port displacement.

15 square inches of port per cube of net volume 18" long should tune to around 40hz and is pretty much a win for this type of sub (or just use any of the cookie cutter DD boxes)

 

[splescort 10+ year member]

3 cuft????

makes no sense

5.53cuft is gross for 28x21x20 outer out of 3/4 wood

then my sub displacement is 0.23 (as per DJ from AQ)

and port displacement is 0.99

so 5.53 gross - sub (0.23_ - port(0.99) = 4.31cuft

bracing i am gonna use threaded rod so at max maybe another 0.10cuft

so total net 4.21cuft.

 

[hispls 5,000+ posts]

3 cuft????makes no sense

5.53cuft is gross for 28x21x20 outer out of 3/4 wood

then my sub displacement is 0.23 (as per DJ from AQ)

and port displacement is 0.99

so 5.53 gross - sub (0.23_ - port(0.99) = 4.31cuft

bracing i am gonna use threaded rod so at max maybe another 0.10cuft

so total net 4.21cuft.

Indeed. Just threw it into my spreadsheet and it looks good. 10" sono tube would make a find round port for that as well.... same length

 

[splescort 10+ year member]

whats better slot port or sono tube and why?

 

[hispls 5,000+ posts]

Round port is somewhat supperior accoustically IMO. Also with sono tube it's really easy to make it a bit longer to try lower tuning then cut it down an inch at a time to experiment with higher tuning, or just carve it out and replace with a longer one if you want to go lower again. A bit less displacement since the walls are thinner, and only 8$ for a 4 footer at home depot.

I find it's simple, functional, and allows a lot of flexibility as far as modifying tuning quickly and without major surgery.