30" long 4" Precision Port

[PoorboyMike]

I'm building a 3.7 ft^3 (gross, I'm figuring a little over 3 after subtracting driver/port/braces/amp) box for a TC OEM12 and as an experiment, I'm going to try porting this thing tuned to 18 hz. Even 20 hz would be OK, which will make it a little easier.

Has anybody had any luck finding pipe and elbows that will work with the thin wall Precision Ports? I was messing around with some 3" PVC parts I had laying around(45 and 90 degree elbows) and I'm pretty sure I can get the required length with some strategic bends. I just don't have the ports in hand yet to see if I can find something that will work.

I thought about the Parts Express flared kit but that elbow looks like a very sharp bend, plus one end is male and they don't have any connector rings available for hooking up a pipe to that end!

[lolojr1]

i have done this before.
there are some thin wall elbows for drainage that fit with a little coaxing its not the average sch 40 pipe that you use to put in a sink or a toilet but the stuff for gutters and draintlie.
it's called sdr35 i think the pipe is green and the fittings should be white although they are a little sharp at the bends so a 45 might work better than a 90 considering that you are using a aeroport to reduce noise

[PoorboyMike]

Thanks lolojr1, I will check that out. My ports should be here today so I can take them to Lowes/HD with me to check for fit.

On the sub you built, how did it sound having such a long port?

[lolojr1]

i had them in my truck and had it tuned really low sounded pretty good it had 1 4" port per 12" woofer

[PoorboyMike]

I went to Lowes last night with a 4" Dayton tube and a 3" Precision Port tube. I went to the plumbing section and found the 4" sewer pipe elbows fit the 4" tube quite well. 2 90 degree elbows hooked together form a nice, gentle arc and give about 19" of port length. I'll just use a short section of the Dayton tube on both ends to connect the ports and will easily get a 30" port in this box.

For the 3", a series of schedule 30 PVC 45 degree elbows also make a fairly gentle arc, and fit good enough to the tube that a seal will be pretty easy, although I haven't measured the length yet. If I wanted to, I could get 2 30" long 3" precesion ports in the box, which would give me the same 18hz tune with slightly less air speed.

A word on the Dayton port kits. The elbow they supply is a very sharp bend and one end is male and one is female. They don't have any couplers in stock to connect a pipe to the male end of the elbow, (they wouldn't even show up in a search with the part # they gave me) so you'll need to find something locally anyway. Also, the fit and finish on the flares is not the greatest. This sub is going to a customer, so I can't send it out with a scuffed up port flare. And they wont just send me a new one, they are sending a shipper 1st, then I have to send this one back before they will ship a new one.