Can someone lower the tuning in this design?

[varietyguy]

sorry .. im usuing a 9515 DD strapped to an AQ 2200.. sorry bout that

Why do you want a 30 hz tuning???? that sub can play WAYYYY below tuning frequency, specially on that big ass box, if you still want to tuned it lower, just shrink the port area a little bit, that sub can still play strong as hell with around 55 SQ of port

Then your port to net Cu. ft. ratio will be off.

Who cares!!!

I think he should. If he has too much port the box could start sounding like crap. And start to decrease spl substantially.

You are confused.

x3!!

I am completely willing to listen and learn. But the way I understand it is 12-15 cu inches of port for each cu ft of air space is what most prefabs do. 15-20 cu inches per cu ft is more on the spl side and meant for lower tuning. 20 cu inches + is for spl specific enclosures and this is when boxes peak at tuning frequency and lose a ton of spl off the rest of the frequency range.

Edited January 26, 2012 by varietyguy

[bkolfo4]

That is incorrect. People have a lot of incorrect information on port area. Only thing worse is all the misinformation on impedance rise

Port area is based on air speed through the port, which is based on cone area x Xmax (called Vd) and port tuning frequency.

95% of the car boxes built do not have the required port area for 100% linear operation at maximum output. That is why it is funny to hear "too much port area". They end up with port compression which alters the operation of the port without them even knowing it because it gets too loud in the car anyway.

Car boxes are almost always designed with a high Q and will peak above port tuning frequency. This has nothIng to do with how much port area you have. It is the design.

To have too much port area would mean having resonant problems within the port itself so that it does not act like a helmholtz resonator because of the port size vs. the box size. More than likely will never happen in a car box. . .

I have run 386 sqin with 11.8 cuft tuned to 34 Hz in a box designed for music. No problem at all.

[Stee-Z]

sorry .. im usuing a 9515 DD strapped to an AQ 2200.. sorry bout that

Why do you want a 30 hz tuning???? that sub can play WAYYYY below tuning frequency, specially on that big ass box, if you still want to tuned it lower, just shrink the port area a little bit, that sub can still play strong as hell with around 55 SQ of port

Then your port to net Cu. ft. ratio will be off.

Who cares!!!

I think he should. If he has too much port the box could start sounding like crap. And start to decrease spl substantially.

You are confused.

x3!!

no haha, my current tuning is 30 hz, Sorry this is the first box i have evr heard my dd in, so i dont know what the difference is if i would tune it around 36, which is where it currently is at. But my current box at 30 hz can get very very low, and I really like the lows! sorry to have any confusion in this thread haha.