Help with 4th order

[power-fanatic07 5,000+ posts]

Ok well I am about to start my next box for these new 12's I got. They are custom built using :

rd elite spl v2 motor

bravox 12'' cast basket 8.5'' landings

8 layer aluminum flat wound d1 coils 2" ww

dual stiff 8" progressive spiders with stiff leads

tc sounds honey comb/ cf cone with highroll surround 8'' poly dustcap

I want to try a 4th order. Going to be using about 3k watts, if it ends up sounding good I have another 3k on tap. I have read through a few threads of the design of 4th and 6th orders but I am no pro. These are the dimensions I came up with. 2 cuft sealed, 5.5 cuft ported tuned to (heres where I'm not sure on the tuning, I have seen a few 4th orders where the ported was tuned to upwards of 50hz) So what exactly will I tune the ported side to? I want it to play low...30-35 hz. And how much port area? 12-16 per cuft ? Thanks for any help

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[rosshimself13 10+ year member]

wish i could be of some help, but i did a google search myself and found some info but didnt save anything... would like to know more about them myself from first hand experience

 

[azimuth 5,000+ posts]

i dont have specs for that sub, but the sealed chamber seems a tad small. as far as the ported area, you want to do as much port area as your design allows. the port could get as large as the sub itself if you have the room. lowest tuned bandpass ive done was 44hz. played pretty darn low. subs that are designed to work sealed, seem to work much better in 4th orders. ported designed subs supposedly work better in 6th order's, but ive never done a 6th order.