posted
Ok, well, I'm building a box that requires a 1.4 cf box and a port that is 3" in dia. and 13.75" in length. Well, since I can not fit 13.75", would cutting the port in half tune the box to the same freq? That is, instead of having one port that is 3"x13.75", have two ports that are 3"x6.875". Is this the same?
the recomended box is tuned to 29hz, and the new box with the 2 ports would be tuned to 53.8 hz !!!! That wouldn't sound to good , to maintain the same tuning with 2 ports they would each need to be 29.5" long
I would just recommend getting your hands on some flexible port, like the JL flexport. It would work very nice in a small box like that.
Ack, that's what I feared... Hmmm...Looks like I'll just have to cut my ports a little shorter than what is recommended. I believe I can fit a port that'd be 3"x12.50". Is there a formula out there that I could use for future reference that'd show me what size and length of a tube port I'd need?? I used to know it at one time...but I've long forgotten it
ea1: Haha, I like the first post! Anyway, I'm stuck using PVC as that's ALL THERE IS AROUND ME! It really sucks living where I do. There are like a cazillion car audio places, but NONE OF THEM CARRY PORTS! CRAPPY huh! So I had to go to good ol' Lowes and get a piece of PVC that is 3"x60". Humph...
posted
That JL flexport is pretty cool. Works real well too. That is my suggestion also.
------------------ GO TEAM GATES IN KC...BEAT EM TO THE GROUND! This has been your daily dose of intelligence brought to you in part by... "The Phil" President and Founding member of TEAM DROP BEATS a.k.a Team Db -1 99' Nissan Sentra -1 Pioneer-DEHP5200 -4 RF 6.5 coaxials -4 Kenwood tweets -2 RF power 800a2's -2 Kove KMG-K 12's(soon to be 2 DD 9012's) -1 3.9 ft^3 41.6 Hz ported box -146.7 dbs Any Questions? please submit to the complaint department, 1123 Yourole knowit drive Causeidontcare IL. 60131
Posts: 2679 | From: unknown bowels of the underworld | Registered: Aug 2000
| IP: Logged |
posted
Check out JL Audio's port tutorial. There is a nice formula for figuring tuning frequencies, etc. Also, you could build a slot port if you didn't want to use PVC.
posted
Ok, so I've been messing around with some figures and I think I found something that might be good for my case. If I only use one port at 3"x11.81" long, that'd give me a desired tuning freq. of 30.71 Hz. Is this right? My port velocity would only be .124. That's good, right? This box is a single chamber box with an internal volume of around 2.94 cf.
Printer-friendly view of this topic