Need help with ports for 1.98 cubic ft tuned to 33 Hz

[afearlesshunter]

I have an obsidian audio 12 going in 1.98 cubic feet. I'm tuning it to 33 Hz with two 3 inch PVC pipes and was wondering if that would work. Their website says to use a 4-6 inch diameter port, will two 3 inch work well? If I need to I can make mdf flares.

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[Phoenix Risen 10+ year member]

two three inch ports is slightly larger than a single 4 (2 square inches to be exact).

about 13 inches long with those 2 3" lands you at 33hz.

Ive had ok luck with pvc ports in the past but flares wouldnt be a bad idea.

 

[afearlesshunter]

Thanks for the quick reply! I just wasn't sure if it would work out well compared to a single 4 . Thanks

 

[Phoenix Risen 10+ year member]

my personal experience multiple ports are a little less efficient than a single larger port, but its usually nothing that is audible unless you start getting port noise, if thats the case i would recommend going with a single 4" or going to a slot port design.

 

[bbeljefe]

If it's in a trunk where vent noise isn't likely to be heard then it's fine. If not, I would go with a slot port or a 4" aero port.

 

[afearlesshunter]

If it's in a trunk where vent noise isn't likely to be heard then it's fine. If not, I would go with a slot port or a 4" aero port.

Are you saying fine without flares or fine for dual 3 inch with flares?

 

[afearlesshunter]

So, i just slapped everything together with no flares and there is a ton of port noise ( i knew there would be) but since its in a sealed trunk I couldn't hear it while playing. Making flares tomorrow to get rid of some of it. 33 hz tuning is a lot different from the sealed box, the trunk lid is not happy though.

 

[bbeljefe]

Are you saying fine without flares or fine for dual 3 inch with flares?

Two 3" vents should be fine, flares or not. But again, only in a trunk. Personally, I'd do a 6" vent aero.