Port Tuning

[iTac91]

My subs (JL 10w0) call for a port tuned to 30 hz. I found a box with everything right except the port is tuned to 40 hz. How much of a difference will this make.

The port is an inch too wide. Could i just add half an inch to each side of the vent and fix it or would i have to move the interior lengths aswell.

[WillPwn4Food]

30 to 40hz is a huge difference. You ever notice how most prefab enclosures are really loud at higher frequencies, but have little to no low end? That's because they're tuned to 40+. Something tuned to 30hz will have FAR better low end, but may not hit the 40hz as well.

Depends what the port area/ft ends up at. If it's at say...12, you could just lengthen the port a few inches as long as it doesn't change your /ft to 16+ or lower your overall volume too much. Get torres box calc. Mess around with a few different port dimensions and see what works. But in all honesty, you'd probably be best off just rebuilding your own from scratch.

[iTac91]

10-4 thanks man

[KMS]

I went from 30hz to 35 hz. Never again will I go over 30hz.

[Triticum Agricolam]

Not to mention a 40 Hz tune is probably going to have a HUGE peak in the response and be really boomy. Lower tuning = better, at least in my opinion, and I'm not alone.

[Joe X]

My subs (JL 10w0) call for a port tuned to 30 hz. I found a box with everything right except the port is tuned to 40 hz. How much of a difference will this make.

The port is an inch too wide. Could i just add half an inch to each side of the vent and fix it or would i have to move the interior lengths aswell.

You should probably post a sketch of that box, there are a few ways to change tuning to an already made box but is hard to recommend something without looking at it.

[BoomZoom808]

I went from 30hz to 35 hz. Never again will I go over 30hz.

I think this depends on the subs you are running. Most of the more experienced box builders I have sought out for advice did not recommending tuning that low.