[19sTEN96]

Hey guys i was wondering what the term "box tuning" means and exactly how you would "Tune" a box. Also could you guys gimme some examples and explainations on ports. I want to know if the direction of the port matters and if it makes a difference with a bigger port or smaller port and the number of ports. Also i have seen a box with the port started out at maybe 3 inches, then went down to like 1.5 inches at the end of the port inside the box.....weird? Any help is appreciated. Thanks

 

[MuddyS10]

box tuning means making the box/subs produce a specific frequency, i think. the port size depends on size of box, subs, and what you want the hz line to be (40, 33, 28, ect). not sure about tapered ports, tho.

 

[HuTcH]

bass technically has no direction so the direction it is facing doesnt matter
down firing up firing side firing will all produce the same sound

 

[19sTEN96]

well im wanting to wander in to the SPL world so i was wondering what would be a good Htz line to produce high dB's and if "tuning" the box would do this.

 

[HuTcH]

tuning the box will do that but you need to have sub specs

a good tuned box is built around the sub not some standardized generic box

 

[MuddyS10]

ive heard 30-36 hz is about the best for daily driver/comp systems. you'd have to use a program to determine this, i think adam728 has it, called Win ISD

 

[03 S10 eXtreme]

good hz? prolly 32-31hz and bellow..well it really depends on your sub and how much air u gonna let it sit in.. wait till adam728 come in..lol

 

[adam728]

Hey guys i was wondering what the term "box tuning" means and exactly how you would "Tune" a box.

Tuning a box deals only with ported boxes. It's a relationship between the airspace, port area (size/diameter) and port length. A good way to simply describe it is by picturing blowing across the top of a beer bottle or the like. Chaning the fluid level changes the tune, so it resonantes at a different frequency.

Also could you guys gimme some examples and explainations on ports. I want to know if the direction of the port matters and if it makes a difference with a bigger port or smaller port and the number of ports.

Ports are used basically as another sub. When music or tones are played near the boxes tuned frequency almost all the sound comes from the port itself, and the sub hardly moves. Because the two work together it is best to have them face the same direction, just like how you'd have both subs fire the same way if running a pair. Bigger ports are usually better, but size is limited by the airspace of the box. The larger port you use the longer it must be to keep the same tuned frequency. Say you have a port 2 inches around and 10 inches long. If you change to a 3 inch diameter port it may have to be 25 inches long to keep the same tune, and often that won't fit in the enclosure. Multiple ports work the same as increasing a single port's size. Usually it is preferable to run a single large port than many small ports (air friction on the port walls has a mild effect on tuning, running 6 tiny ports screws with your real-world play vs what you calculated).

Also i have seen a box with the port started out at maybe 3 inches, then went down to like 1.5 inches at the end of the port inside the box.....weird? Any help is appreciated. Thanks

Not real sure on this one. There are snail-shell enclosures that use this type of setup, but they are VERY complicated and much different from a ported box. Horns also work like this, but again, don't have much in common with a ported enclosure. Putting a tapered port in a standard box will not have good effects. All tuning calculations get tossed away, and I cannot picture performance being good at any point.

As for tuning, it depends on what you are looking for. Competitors tune high, way high, like 40-55 hz. This means they can only really use their stuff for competition. Why? Because a ported box does not play below the tuned frequency. If you hit a low note with a high tune the sub flops like it is sitting free-air on a table, and that is BAD for the sub (power handling is cut litteraly to 25% rated).

Sound quality guys look to run about 32 hz and lower, some guys go as far as 20 hz, but I think that's crazy. Upper 20's-low 30's is good.

For daily driving a good mix of sound quality and output is 33-38 hz. There is variations to any rule, but this is a general idea. I ran my old box at 36 hz and liked it. My new one is 33 hz and I'd like to raise the tuning a little to get some more output (but overall it sounds good, better than when I run it sealed).

Anyway, I'll try and answer anymore questions tomorrow. I just came home to get cleaned up, and now I am late as hell.........

 

[adam728]

This post may help you as well:

http://audioforum.termpro.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=40;t=009769

 

[adam728]

And 03 S10 eXtreme
The displacement being much larger than I guessed is the reason my port length and Tempe's differed. I've got a lot more for you tomorrow (liek why 13 inches is too tall).

 

[03 S10 eXtreme]

lol okae, thanks a whole lot adam i really appreciate it

 

[93ex]

bass technically has no direction so the direction it is facing doesnt matter
down firing up firing side firing will all produce the same sound

ONLY BELOW 100HZ I BELIVE sorry for caps

 

[adam728]

bass technically has no direction so the direction it is facing doesnt matter
down firing up firing side firing will all produce the same sound

Bass is totally directional, at any frequency (just like all other wavelengths). The reason people say it's "non directional" is because below about 90 hz the waves are so long that the pathlength between your ears is nearly identical, meaning your brain can't pick a direction for which it is coming. It still behaves directionally, with cancelation and reflections and such. This is why is it important to keep subs and ports on the same plan, so you don't have them competing with one another.