when tuning a box...
 

ok i guess i should first ask, what the **** does it mean to tune a box?
like what purpose does it serve? i hear people say they tuned their box to 38 hz or 35 hz or whatever, but i have no idea what the hell this means. i guess i want to know too because i was planning to build a bandpass for my subs in an attempt to get some tighter bass while still keeping the extended lows i get from my ported box now, plus while i look for a new job i figure it will help to pass the time...damn recession. any help will be appreciated

good luck with that.
if you're really not too sure, why not have someone design a box for you?
or have someone build you one?
its not super easy to explain how to tune an enclosure over the internet.

ya, you should probally consider having a box built for you....a bandpass box doesnt usually offer a tight, controlled sound. theyre very picky to tune right and will have a well pronounced peak note

well i just want to know what the purpose of tuning the box is. say its tuned to 38hz, what does that do to the sound? does it make notes closer to 38hz sound louder? or does it make all notes lower sound louder? that is my real question.

I'll try to explain, I makes the notes in that area louder and you can gain db's if tuned to the right frequency for the set up, but if its tuned to low for the set up it can make your stereo lose db's and it will be hard on your subs because of the F3 on the passband.

Please start by reading this article:
The Subwoofer DIY Page - Ported Systems

It would help if you read all the articles.

I would really not recommend you attempt to design and build your own bandpass for your first attempt at building your own enclosure. Many seasoned box builders have problems with them.

Also, I believe sealed or ported enclosures are almost always better solutions to a bandpass.

If you're really interested in enclosure design and building, download WinISD and play around with it. Go through the help files...it will explain a lot. Good luck.

Yes, output from the port (rear-wave) adds to overall output around AND above the tuning...with most of the constructive output at tuning. Does this help, or is that confusing?

build a abc box , i make them locally and people love em
hits super hard and pretty clean, there was a huge post on tempro a few years back might still be there

awesome guys thanks for the help

Hrm..ok, so basically what I'm understanding from all this is pretty simple. Tuning to a certain frequency will increase DB at and around that frequency, but if you're too far away from the base frequency of you subs/amp then the drop will make crappy sound?

My amp has a 20HZ subsonic filter that I keep on, so if I was to tune my box to somewhere in the 30-35 HZ range then I should get really good results, right? Also, my amp has a cutoff of I believe 240HZ, given that it is a Mono block. Having said that, since tuning too high makes the drop sound crappy, does the difference between tune and higher frequencies matter much?