4th order bandpass box designs

I think this is a bad idea. Those little 8"s have an fs of 47hz and you want to tune them to 20 hz in a small box? No way. A bandpass box is not a simple design and will not give you a nice flat response 20-60hz. The xmax on those subs is less than 5mm, no were near enough displacement to get any usable sound at 20Hz. I suggest a simple ported 12" or 2 10", maybe 2 12" if you want good output at 20Hz.

Never said anything about a small box. Thinking of 6-8 cubes gross.

I understand the 4th order is not a simple box by any means. I have built them in the past, just had other people design them. All the 4th order boxes I have built thus far have had amazingly nice 50-20hz slopes.

what he is saying is you wont get what you are looking for with the subs you have.

got_focus? said:

...Max dimensions - 40" Wide, 18" Tall, 12" Deep

Click to expand...

got_focus? said:

Never said anything about a small box. Thinking of 6-8 cubes gross...

Click to expand...

Your dimensions allow a 3.86 cube enclosure MAX, assuming .75" wood, no port, and no bracing. Not even compensating for driver displacement. Not sure how you plan to get 6-8 cubes out of nowhere.

Bandpass boxes are not know for their low end output. They have very steep roll-offs so there is not much cabin gain and to be honest I can't think of any situation where I would use them over a ported box.

Guess I will just do a ported....thanks

TREETOP - I posted the max dimensions before playing with the 4th order calculator and realized I would need a much bigger box. I was just trying to conserve some trunk space initially.