Need these sub plans reviewed before I start the build

[kelticwizard]

Two 3" diameter ports of 30" length, (better use some elbows), will take up about 7 liters of space. Add about 4 liters for the driver, and you have about 10 liters to deal with that will not be counted toward box volume. So your 85 liter box is actually 75 liters. Actually, the difference between 75 and 85 liters is not that much-or you can add a little extra space if you want.

Two 3" diameter ports of 30 inches tune an 85 liter box to 20 Hz. They will be 22" if you tune to 23 Hz.

Come to think of it, I think Stryke has a design of it's own that calls for three 3" ports. I think BAM was building it. I'll check. I think two 3" flared ports will be adequate, though.

[kelticwizard]

Here is the thread. BAM's project is a little bit smaller than yours, though.
AV12 Design Aggravation

Incidentally, I do think that having the ports firing downwards probably means that you can build the ports of a somewhat smaller diameter. Can't verify that, though.

To sum up, if I were building this I would increase the box size only slightly to accommodate the 10 extra liters, (really, that is very small), have the woofer firing frontward and have two 3" ports firing downward. That is how I would do it.

[planet10]

The 85L sealed looks pretty good to me... Still has an F10 @ 20 Hz. Match that up with room gain and you'll have good bass.... when you add in the ApexSr 6 dB of boost at 30 Hz you still might have too much. I'd be looking at wiring in a bass boost defeat switch and seeing if i could get the thing to roll off earlier & slower -- keeping the same size box, you'd have to go aperiodic -- which jives with Roddy's suggestion, because an aperiodic could be considered a leaky sealed box -- stuff the ports with foam, instead of just plugged.

dave

[AudioIsFun]

Originally posted by kelticwizard
Two 3" diameter ports of 30" length, (better use some elbows), will take up about 7 liters of space. Add about 4 liters for the driver, and you have about 10 liters to deal with that will not be counted toward box volume. So your 85 liter box is actually 75 liters. Actually, the difference between 75 and 85 liters is not that much-or you can add a little extra space if you want.

Two 3" diameter ports of 30 inches tune an 85 liter box to 20 Hz. They will be 22" if you tune to 23 Hz.

Come to think of it, I think Stryke has a design of it's own that calls for three 3" ports. I think BAM was building it. I'll check. I think two 3" flared ports will be adequate, though.

Ok so I'm going to use some new plans for a 95 L enclosure to account for the extra 10L of the driver and tubes. Here are the new diagrams. They are not exactly to scale, but I tried to make it close. I need these plans revised again if you guys could give them a look. Now for another question. I see flared ports by Madisound and Partsexpress but they are too short. I can buy elbows from HomeDepot but I still need more 3" tubing. I know I can buy 3" PVC from HomeDepot also, but don't they sell them in like 10feet+ things of tube? I only need like 4 feet, if that. I was thinking I could buy these flared ports, 3" x 11-1/2" PORT TUBE DUAL FLARED , and then cut them in half, couple them to some cut 3" PVC, if I can acquire some, and then to the elbow. I would use the bracing in the middle to help brace the port as I think it will be top heavy. Does anyone know how much 3" PVC at a hardware store costs? Please look over my plans and let me know about the materials for the port I need. Thanks again for everyones help.

-Ed

P.S. How far do the ports have to be from the inside walls? I thought I read somewhere that they had to be at least 3" from any inside wall? Please let me know so I can position these ports better if needed.

*The outer square is of the internal dimensions in both pics.

[AudioIsFun]

Not exactly to scale, but close.

[AudioIsFun]

any thoughts?

[BAM]

Post up the T/S parameters you have for the SAE1204 and I'll come up with something for your driver.

[kelticwizard]

AudioIsFun:

Your guess is as good as mine as to where to get 3" diameter PVC pipe in less than long lengths. I don't think it is all that expensive, though.

You can run the vent along an interior wall if you want, with one important provision. The opening of the port should be free of any stuffing and somewhat away from the wall. Actually, you can put the opening along a wall, without stuffing in the immediate vicinity, but it does lower the tuning somewhat-not sure how much, just a little. The important thing to keep in mind is that the port must be unobstructed by stuffing-you want free flow.

Since you are going to have flares on both ends, if you run the vent along the wall, you will have to turn the vent inward in order to make room for the flare.

One suggestion I would make is that if you want to brace the long vent, use a muffler clamp to attach the PVC pipe to whatever brace you wish to make. Makes things easy.

[AudioIsFun]

Originally posted by BAM
Post up the T/S parameters you have for the SAE1204 and I'll come up with something for your driver.

T/S Parameters:
(VC's in parallel)
FS 21 Hz
Qms 15
Qes 0.342
Qts 0.334
Vas 110L Liters
Cms .32 mm/N
Mms 177 grams
Sd 492 cm2
Rms 1.565 Kg/S

Physical Dimensions:
A= 12.32" B=11.07" C=5.63" D=6.15" E=2.50" F=.32"

Here is the website I got the info from. Apex Jr

Thanks a lot for helping me. I really appreciate it. Thanks to everyone for helping me. I will post pics when I have a chance to actually build the sub. I am still acquiring some tools that I need, and I have lots of midterms around now. Hopefully I'll have some time next week. Thanks again.

-Ed