Subwoofer Build - Vented

[DeathMonk]

I already have the driver (shiva-x) sititng in my dining room. I am getting the 500w oaudio plate amp for my bday in a couple weeks.

Reading the design choices and per Kevin (diycable) I have decided to go vented (~5-5.5cu. ft.).

I don't like the idea of chuffing. I have tossed around the idea of doing 2x4" or 1x6" port or even a slot port.

I also hear that the PR should be available soon.

I am stuck on deciding what to go with. Would one 4" be unbearable?

I was also stuck on a few questions:

How do you calculate for bends in ports? Is there much of a difference to worry about?

Is calculating slot ports done in winisd by changing the port shape and entering values? Do the bends (or 90deg. turns) in slot ports need to be calculated?

I think that about does it

DM

[ThomasW]

A 6" port is really overkill for a 12" driver. I think a 4" port with dual flared ends is fine. If per chance these do chuff, the output from the driver will be so loud you won't hear the port chuffing.

How do you calculate for bends in ports?

Imaginary line down the middle of the curve. Don't think you need to worry about curves with a port that's only 17" long

Sorry I don't do slot ports. If they're long enough for a low tuning they make the box much heavier....

[DeathMonk]

Thanks Thomas,

I was more thinking about the 6" port for the bends. I was just a little worried about a single 4" by the calculated port air speed in winisd and in the application guide.

I really didn't consider that the spl will overpower any chuffing that would be experienced.

[ThomasW]

I use a dual flared end 6" port for high excursion 15"s, there really no reason to use a port that big for a single 12".

For 4" diameter or smaller ports I'm a fan of the Precision Ports brand with their dual flared designs. These can move a bunch of air. (basically they flow like a 5" straight port)

[DeathMonk]

cool.. I'll go with the design I originally had in mind, then.