Tuning hell

[g2shuck]

Ok guys I have redesigned my wall about 18 times in the last two days. The problem I am having is I will be competing in normal midwest spl classes but also loud and low with is 20, 25, 30, 35hz average so I need to do mid 150s at 20hz lol. Two dc level 6 m3 18s drivers side ported wall. What the hell should I tune the box to to meter high at 20hz but not fall on its face at 40hz. Also how much prt area I know I need 12 cubes net. Goal is mid to high 150s from 20hz-50hz. Will be clamping around 5000 watts to eah sub after rise.

[g2shuck]

basically asking for a mariccle box lol. low 150s at 20hz would even be ok for competing in that class. Have been told not to forth order a level 6 and do not think I can even come close to fitting a 6th order for two 18s

[SnowDrifter]

A guy on team nwspl does a 156 sealed on the dash at 28hz. 2 level 6s in a 6th on a pair of 5ks.

How much space do you have available? Tuning that low with a normal ported box is going to cost you big time on your scores.

[Meka]

Have you thought about adjustable/removable port? Interested in hearing other ideas.

[g2shuck]

A guy on team nwspl does a 156 sealed on the dash at 28hz. 2 level 6s in a 6th on a pair of 5ks.

How much space do you have available? Tuning that low with a normal ported box is going to cost you big time on your scores.

28hz is along way from 20hz lol. The part I highlighted is the issue I keep running into.

[g2shuck]

Have you thought about adjustable/removable port? Interested in hearing other ideas.

Thats what I have been messing with tonight. One problem is with a short 40hz port in I woule be at close to 16 cubes net which is way to big. That is becuse the net volume has to be big to fit a 40 inch long port in for the 26hz port.

[SnowDrifter]

What are the rules for your class? Perhaps you are optimizing too much for 20hz. To the point where your score may suffer due to the quiet scores on the other frequencies.

You are basically asking for the impossible. A member on here, baaudio has 4 15s in a flat wall on 20k ish. He can hold a 150+ at 20hz. May want to ask him for advice

[TZspeakersZac]

No room for a 6th order bandpass? Well, you can always go with an external port and not change internal airspace at all, or make a 40hz port with an optional external extension for a 20hz tuning. It might work, but if you can't fit a 6th order I don't know if you can fit an external port.

[g2shuck]

loud and low rules I posted above other class will be 3 minute music average with a couple guys are doing high 150s in currently. I will NOT be doing any burp classes. I have been talking to baaudio and wish he would let me pay him for a wall design. He told me to tune to 24hz but with the level 6s im scared to tune that low honestly with such a high fs. I have bass box pro 6 but for some reason the level 6 does not work right in it.

[g2shuck]

No room for a 6th order bandpass? Well, you can always go with an external port and not change internal airspace at all, or make a 40hz port with an optional external extension for a 20hz tuning. It might work, but if you can't fit a 6th order I don't know if you can fit an external port.

B pillar wall no room between wall and seat for external. I can get around 28 cubes gross but 1.5 walls, 1.5 port, and 3 inch thick baffle, bracing, and .54 sub discplacement that drops fast.