Box Design decision

[OldsBoomer]

Alright everyone just wanna say good to be back and ill be back for good because of some stupid bs... anyways

The blowthru is getting rebuilt. Ordering the recones for the 4 12" Fi Q's today. I need to make up my mind on my box design so i can hopefully start building this week and im stuck between 2 designs. ones a 4th order and one is like sanitariums blowthru.

My original design:

this is what happened to it since i decided not to use it again considering the box rise(started at .7ohms rose to 9ohms )

First design:

Its a rough drawing but each sub face is 13.5" long and then an port length of 10.5" its about 8.6-9ish cubes with about 146.25" of port.

The box is 39.5"Wx14.5"Hx49.5"L

4th order:

This is just the rear chamber it'll turn out to about 3.3-3.8ish cubes depending on the bracing I do. the first 2 subs will be inverted. The front chamber would be about anywhere I wanna make it but im thinking a good 4.5-5.5ish cubes tuned to 39hz with around 78-91sq in of port area.

Im just torn between the two. I know 4th orders are picky and take time to dial in just right, I would love to build it but I dont have the time, space,money, or tools to keep pulling it out and working on it and putting it back in.

Whats everyones thought?

Edited May 16, 2011 by OldsBoomer

[OldsBoomer]

one vote... come on I know there are more out there lol

[hdorre]

I LOVE the look of Sanitarium's bandpass. Aesthetically, it shits all over the basic 4th order imho

I dont know which one would be "better" though

[OldsBoomer]

I LOVE the look of Sanitarium's bandpass. Aesthetically, it shits all over the basic 4th order imho

I dont know which one would be "better" though

me either i know i want efficent but both are very efficnt

[hdorre]

I would think that efficiency would be based MOSTLY on the box design. If you could find a good designer (like Sanitarium for his box or dwright27 for 4th orders), you should be happy with either in a DD. Will you be competing?

[OldsBoomer]

I would think that efficiency would be based MOSTLY on the box design. If you could find a good designer (like Sanitarium for his box or dwright27 for 4th orders), you should be happy with either in a DD. Will you be competing?

of course ill be competing and well my series is similar to sanitariums and i haven't done a 4th order yet i was thinking of designing one for only 2 subs first then double it. but whats wrong with my designs lol i did a 146.1 on 546.7 watts lol rise just killed me.

[hdorre]

Whats wrong with your designs? The current box has a ton of rise. What did it rise to? Like 9 ohms from 1? I guess you could get a program like WinISD to guesstimate though

Yes, I have to keep in mind that it did get really loud on such low power

[Azagtoth502]

I say build a 4th and make it SLAM!

[OldsBoomer]

Whats wrong with your designs? The current box has a ton of rise. What did it rise to? Like 9 ohms from 1? I guess you could get a program like WinISD to guesstimate though

Yes, I have to keep in mind that it did get really loud on such low power

there is no way to tell what your rise will be its very tricky. no way to guess what it will be.

[hdorre]

Thats why I said "guesstimate" I thought WinISD predicted impedance for each frequency. Maybe Im confused with its prediction of Frequency Response