6th order wall design

[kr15 5,000+ posts]

So we will be attempting a 6th order wall with 2 x v2 15s. The ebp leans toward 4th, but we will be trying a 6th for spl purposes. We think we will end up with a more narrow pass band, but higher peak.

We have up to 6cu for rear chamber, and probably 16-18cu for front chamber.

So...to begin, how should we determine chamber volumes and tuning if this is for spl?

Im privy to 4ths, not to 6ths. Any input is appreciated

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[kr15 5,000+ posts]

Or...... are we wasting time when we could just do a high ratio 4th?

 

[Lbetts818]

Tuned in for this. Considering 4th walling my 07 trailblazer with two x15s v1 with spl soft parts though.

 

[kr15 5,000+ posts]

Hopefully cscstang or 1 of the guys with alot of BP knowledge will chime in

 

[Hertz Mafia]

Not sure for all out SPL build but I'd do 9cubes ported at 25hz and front chamber 18+cubes tuned to 50hz

 

[kr15 5,000+ posts]

When designing a 6th, should the rear more a less be the ported volume the subs need? Then the front is obviously sized per ratio?

I thought we could get away with less volume in rear chamber. But if we cant, we might as well do a 4th. Especially since ebp leans that way

 

[mrj858 10+ year member]

Rear chamber should be what the subs call for in a ported box...it's more to it then just ratios....ratios can make you peakier with less bandwidth...BUT if tuned properly to your cars resonance frequency it helps gain you free spl....mine for instance is a 1.35 to 1 ratio...22hz tuned rear and 46hz tuned front...last subs before I switched subs and amps were a pair of Zv4 18s and and TFE at .5....did a 155 sealed on the dash at 29hz and 154.6 sealed on the dash at 53hz...bandwidth was 15hz-62hz before drastic roll off...played 20hz-55hz pretty flat within 2db

 

[kr15 5,000+ posts]

Ok so since our absolute max in rear is 6cu, we should definately stick to a 4th....

Now to the 4th. My teamate is thinking 1.75 sealed side. I think thats too small. We would do 3.5 sealed, 14 ported tuned at 45. Thoughts?

Power on tap is wayyy over rated power

 

[kr15 5,000+ posts]

Oh and its probably ambitous... but goal is 156+ sealed and 158+ kick. That is basically where we need to be

 

[Jeffdachef 5,000+ posts]

Or...... are we wasting time when we could just do a high ratio 4th?

Stick with 4th with those subs build the sealed chamber then test your resonant freq then build the ported. I would go small on the sealed portion if you want more spl than lows.

 

[Papermaker85 5,000+ posts]

I've always designed the as rear volume is for the low tune and front is for the high with around doube the port area. In series. Not as for a parallel 6th order it doesn't matter

 

[Papermaker85 5,000+ posts]

Sealed chamber depends on the sub. But yea i think 1.5 is small. 2.25 is probably more ideal. So 4.5 rear and 9 front tuned close to your response should be pretty good

 

[Hertz Mafia]

Ok so since our absolute max in rear is 6cu, we should definately stick to a 4th....
Now to the 4th. My teamate is thinking 1.75 sealed side. I think thats too small. We would do 3.5 sealed, 14 ported tuned at 45. Thoughts?

Power on tap is wayyy over rated power

I heard 15s like 1.2-1.75 cubes sealed for 4th orders.

 

[Jeffdachef 5,000+ posts]

Sealed chamber depends on the sub. But yea i think 1.5 is small. 2.25 is probably more ideal. So 4.5 rear and 9 front tuned close to your response should be pretty good

not the case with high motorforce subs, they like IT SMALL. buddy's 4th got way louder with more bandwidth when we shrank it. Apparently alphard db 3 12s need about half a cube sealed or less according to the loud russians that run them. buddy had them 1 cube. could only shrink to .75 cubes.

 

[kr15 5,000+ posts]

So 1.75 seems like the middle ground. Maybe go down to like 1.6?