4th order question.

[dudeogo]

So I've seen on a lot of 4th order enclosures the ported section of the box is basically just missing one side and it's almost as if the entire box itself is the port? How does that work with box size, and how do I find tuning for that? Just wondering it's been driving me crazy. Any answers are appreciated!

Click to read more...

 

[X-Drive]

I did bandpass 4th order in Nissan Micra. Closed box is 40 liters, vented box is 135 liters. Port is tube at 200 mm diametr and 350 mm long. Play very good.

Sub is Ural Patriot 15" and amplifer Pride 2k (2000 Watt)

 

[shredder1 10+ year member]

So I've seen on a lot of 4th order enclosures the ported section of the box is basically just missing one side and it's almost as if the entire box itself is the port? How does that work with box size, and how do I find tuning for that? Just wondering it's been driving me crazy. Any answers are appreciated!

Are you talking about going big with something like this?...

or staying under the window line with something like this

Hehehe... I've been following your other thread...

 

[Jeffdachef 5,000+ posts]

you have to tune high to the resonant sealed resonant frequency for best bandwidth and output which is very high like in the upper 40s and 50s. So thats the only way to get a high enough tuning. Plus you start higher and shrink via experimentation to find that perfect sweet spot. To do a 4th order you better d@mn well have some RTA/SPL metering equipment or else its doomed to be mediocre or fail.

 

[X-Drive]

you have to tune high to the resonant sealed resonant frequency for best bandwidth and output which is very high like in the upper 40s and 50s. So thats the only way to get a high enough tuning. Plus you start higher and shrink via experimentation to find that perfect sweet spot. To do a 4th order you better d@mn well have some RTA/SPL metering equipment or else its doomed to be mediocre or fail.

Yes, I'm also experimentation to find perfect port witn SPL-LAB BassMeter

 

[dudeogo]

you have to tune high to the resonant sealed resonant frequency for best bandwidth and output which is very high like in the upper 40s and 50s. So thats the only way to get a high enough tuning. Plus you start higher and shrink via experimentation to find that perfect sweet spot. To do a 4th order you better d@mn well have some RTA/SPL metering equipment or else its doomed to be mediocre or fail.

I have friends with metering equipment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Jeffdachef 5,000+ posts]

I have friends with metering equipment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

its very important to get the sealed portion right. Some stiff suspension subs with super high motorforce would only require like half a cube sealed for a single 12. Its weird.

 

[dudeogo]

its very important to get the sealed portion right. Some stiff suspension subs with super high motorforce would only require like half a cube sealed for a single 12. Its weird.

I used winisd and i kept playing with the graph and ended up with what I wanted at 4 sealed 6 ported for one 18

 

[hispls 5,000+ posts]

I did bandpass 4th order in Nissan Micra. Closed box is 40 liters, vented box is 135 liters. Port is tube at 200 mm diametr and 350 mm long. Play very good.
Sub is Ural Patriot 15" and amplifer Pride 2k (2000 Watt)

good looking box.

I used winisd and i kept playing with the graph and ended up with what I wanted at 4 sealed 6 ported for one 18

Good luck.

 

[dudeogo]

good looking box.


Good luck.

I'm just playing around rn. I know someone who will buy an 18 as soon as I'm done with it. So I just wanted a little big sub wow factor for a month or two in the highschool parking lot while I find a beater Jeep.

 

[THATpurpleKUSH 5,000+ posts]

Try starting with a 1:3 sealedorted ratio with tuning around 48-52hz and go from there.

 

[dudeogo]

Try starting with a 1:3 sealedorted ratio with tuning around 48-52hz and go from there.

I've already started the build. But if I hate it I hate it, it's not like it's a wall. I'll learn from my mistakes and build another box.

 

[hispls 5,000+ posts]

I've already started the build. But if I hate it I hate it, it's not like it's a wall. I'll learn from my mistakes and build another box.

That's the spirit!