lets discuss 4th orders

[Forrest Gump 10+ year member]

http://www.carstereo.com/help/Articles.cfm

 

[Wkbdkid 10+ year member]

Tommy is right. From what Ive heard in different boxes when you build the sealed chamber bigger, it plays lower. With a bigger ported chamber, it plays higher. Thats how all the Extreme class cars are set up. Especially in EXT1. Theres a HUGE shell that you can go inside, then a super tiny box thats barely big enough to fit the magnet/basket of the sub in, way back in the corner. Thats the very small sealed, with the huge ported. That gives them the huge peak up high, right where they need to play their single note around 75-80hz.
My van personally is 50 cubes sealed, 35 cubes ported, with around 900-950 sq in of port tuned to 47hz. It plays everything. Plays low, plays high, plays high punchy bass, low punchy bass, plays the loose down low fluttering below 10hz, plays the 80hz teeth-chattering note and everything in between. It could be designed to have the peak around 43hz and be a mean bassracer on the meter, but its a daily driver built to play music and demo. It does just what I want it to.

Say you have a 12" sub. If you put it in .5 sealed, and 3 cubes ported, tuned to around 60hz with alot of port it will be a fart box. The sub sees the tiny sealed box, which gives it the tendency to play higher. Then when you couple that with a big ported chamber for efficiency and a big port to be least restrictive to airflow, you are going to be metering quite well up high.

If you put the same sub in 1 cube sealed, 1.25 ported, tune it 45-55hz with a smaller port, it will see the larger sealed chamber, letting it play lower. Coupling the larger sealed chamber with a smaler ported chamber tuned lower, it will have a much greater low end and ability to play music.

One thing Ive seen that seems to be a good rule of thumb, is the ratio of sealed to ported affects whether it plays music or is a SPL box. If the sealed/ported ratio is 1/1.5, it will play real low, and be great on music. If its 1/5, it will have a very high peak, and meter quite well.

Bandpasses let you control the sound much more than a conventional ported or sealed box. You just gotta know how the different parts of the box work together to get the sound you want.

Im still learning about bandpasses, and only have some knowledge on 4th orders. I still want to learn much more, as what some people do with bandpasses is just amazing! They all say its too hard to explain and only first hand testing shows you how they work. Ive seen what they are talking about. After playing with them, hearing alot of them, and discussing with people who have been building them forever, I have learned alot... But still have so much more to learn.

Wow, that was a long post.

Thats a good *** post. Good info to get started on some shit

 

[TeamRetribution 10+ year member]

Mine plays the lows just fine ....

 

[galacticmonkey 5,000+ posts]

Im not sure if its correct... Thats just my hypothesis from first hand experience.

 

[pioneerpimp 5,000+ posts]

seems as though thats the general explanation we get from people with 4th orders though, so it may be correct.

 

[Forrest Gump 10+ year member]

Did you check out the link in post 46?

 

[galacticmonkey 5,000+ posts]

Did you check out the link in post 46?

n0 wai dood //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[Mr. Slate 10+ year member]

Did you check out the link in post 46?

Wasn't really helpful for wall builds but it should be good for regular size boxes.//content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[Mr. Slate 10+ year member]

Experts chime in and Happy New Year.

 

[pioneerpimp 5,000+ posts]

up for teh good info