dual reflex bandpass 6th order enclosure

caliph tec · Postby **caliph tec** » April 25th, 2016, 8:24 pm

OK guys so been watching some videos on dual reflex band-pass 6th order enclosure on you tube i no its ah very old box design but i saw ah lot off Foreign car audio guys using that design and getting a very good output form d enclosure.
what i am looking to achieve is a flat respond as stated d 6th order enclosure does that,my idea is to design box to recommend cf for sub but my problem is how to tune the ports,for eg was thinking off tuning the rear port to a high fq and d front port to a low fq (front 28hz rear 70hz). not sure if any off ever try this local but i never saw nun except for factory band-pass.
I no it have many guys here have lots off experience with building and tuning sub-woofer boxes so your input is highly appreciated thanks

Brian Steele · Postby **Brian Steele** » April 26th, 2016, 12:38 am

Choosing arbitrary tunings for a 6th order BP design is a bit like choosing arbitrary tire sizes for your car's rims. Expect to achieve an equal amount of success in both endeavors.

Chamber sizes and tuning for a correctly-designed 6th order BP enclosure will depend not only on what driver you're using in that alignment, but what target response you're trying to achieve.

caliph tec · Postby **caliph tec** » April 26th, 2016, 6:23 am

Brian Steele wrote:Choosing arbitrary tunings for a 6th order BP design is a bit like choosing arbitrary tire sizes for your car's rims. Expect to achieve an equal amount of success in both endeavors.

Chamber sizes and tuning for a correctly-designed 6th order BP enclosure will depend not only on what driver you're using in that alignment, but what target response you're trying to achieve.

Understand what u saying, we'll I want to try it with a small sub before I move on to my big sub.d sub I want to try it with is a skar audio vvx 8"once i get success I will move on to my bigger sub, now this sub maximum cf is 1cf so Im thinking to put d rear chamber as 1cf but not sure what cf to use in front chamber so im kinda confused

Brian Steele · Postby **Brian Steele** » April 26th, 2016, 11:29 pm

caliph tec wrote:Understand what u saying, we'll I want to try it with a small sub before I move on to my big sub.d sub I want to try it with is a skar audio vvx 8"once i get success I will move on to my bigger sub, now this sub maximum cf is 1cf so Im thinking to put d rear chamber as 1cf but not sure what cf to use in front chamber so im kinda confused

There are a number of free s/w programs that can model 6th order BP boxes. Hornresp, for example. If the Qts of the driver is over 0.3 though, I wouldn't bother - you may be better off with a simple vented box or transmission line alignment.

caliph tec · Postby **caliph tec** » April 27th, 2016, 11:51 am

D qts off d sub Is 0.54

caliph tec · Postby **caliph tec** » April 27th, 2016, 11:55 am

D qts off d sub Is 0.54

ruffneck_12 · Postby **ruffneck_12** » April 28th, 2016, 8:18 pm

WinISD has a pretty cool parallel tuned 6th order calculator, BBP does too but with winISD you can play around with the tuning/volume of the box with the mouse and see the response in real time

It takes some handy work to arrive at a suitable set of parameters,,, but in most cases to achieve a flat response, the bandwidth does end up narrow AF. Or if you get a broad bandwidth, the box ends up being really huge.