Buildlog for Rl-i8 fiberglass enclosure

[negativezeroz 5,000+ posts]

Ok I started building a fiberglass enclosure for my Rl-i8 that is expected to be here Wednesday.

I popped the mold out yesterday. I am about to go add more layers to the mold because it's weak in some places.

Anyways, my problem is the port. I started another thread asking about port width and length. The port was set at 3" wide and 26" long for tuning of 30Hz in ~0.75cf.

Well, I was just at lowes and the 3" PVC pipe is rediculous. There's no way I can get the 26" length.

How much shorter would the length be to change the tuning to 32Hz? I don't want to tune there if I don't have to but using 3" piping I need to cut down on the length.

Here are some pictures: (yes it's not very good but this is my first completely fiberglass enclosure)

Click to read more...

 

[negativezeroz 5,000+ posts]

Here's the only way I can think of of running the piping..

The very bottom line where it will come out of the enclosure I can get like 15" using 3" before I'd have to get an elbow.

 

[jeremiah 10+ year member]

for 32hz the port is 22.61"

 

[jeremiah 10+ year member]

maybe if you do it to 35hz it can fit 35hz is 18.54" long

 

[negativezeroz 5,000+ posts]

hmm 22.61 so basically 3 shorter..

well maybe I should just take the mold up to Lowe's and test fit pieces or something..

I want 30Hz but man..if it was 2" pvc it'd fit no problem lol but I know I'd get lots of noise...

 

[DejaWiz 5,000+ posts]

How about a 3.5" or 4" port?

 

[negativezeroz 5,000+ posts]

How about a 3.5" or 4" port?

if it makes the port shorter I could see

 

[jmanpc 5,000+ posts]

3" Port for .75cf? That's a hair big.

 

[negativezeroz 5,000+ posts]

3" Port for .75cf? That's a hair big.

well I want to tune to 30Hz so what size should it be? //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif

 

[jmanpc 5,000+ posts]

2" would be plenty for a single 8" sub

 

[DejaWiz 5,000+ posts]

if it makes the port shorter I could see

Aaaahhhhh. Bigger diameter port = longer port for the same tuning freq. Duh. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

Then how about two 2" ports at 19" each? Would be about 33 Hz.

 

[jeremiah 10+ year member]

if you do a 2" port do a flared port to cut back on port noise ( if there is any)

( 2" flared port 12.08")

 

[negativezeroz 5,000+ posts]

so (1) two inch port at 12" long = 30Hz?

 

[jeremiah 10+ year member]

yes

 

[negativezeroz 5,000+ posts]

I will send you some moniez through PayPal when I sell my **** alarm on here for helping me.