4th order for 2 lvl4 m2 12s

[soundsystemaniac]

I have been asking around for advice on this 4th order and have gotten a couple different replies and I wanted to see what the feedback here is.

Car: 2012 Audi A4

Equipment: 2 DC level 4 12" M2, XS power d4900, 1 Crescendo Audio BC 2000 at 1 ohm

Goals: play daily music from 32/33 hz to 65/70 hz with authority and Flat!

Constraints- will be ported through rear deck. I have ~ 7cubes before any displacements to play with.

I have gotten feedback of doing 1.3 sealed and 4 ported with 55 sq inches of port @ 50 hz.

I have also gotten doing a 1:1 or 1:1.5 ratio to keep the response flat.

Whats your advice?

Thanks in advance!

[vetkilr01]

Thats almost exactly what mine where just in, but tuned to 46 hz. Was very flat and played low, that amp is to small IMO...I was running a bc3500 and they were laughing at it. Rise is high in a 4th order, mine was wired to .5 but rose to almost 3 ohms.

[soundsystemaniac]

Thats almost exactly what mine where just in, but tuned to 46 hz. Was very flat and played low, that amp is to small IMO...I was running a bc3500 and they were laughing at it. Rise is high in a 4th order, mine was wired to .5 but rose to almost 3 ohms.

the 1.3 sealed and 4 ported?

[soundsystemaniac]

This Is what I have come up with. 1 cubic sealed for each sub plus displacement of .18 gives me 1.18 cubes sealed per sub. 2.5 net ported at 49.xx hz with 49 sq inches of port. Do you guys think this will work?

[Purplehaze]

This Is what I have come up with. 1 cubic sealed for each sub plus displacement of .18 gives me 1.18 cubes sealed per sub. 2.5 net ported at 49.xx hz with 49 sq inches of port. Do you guys think this will work?

You have to subtract the displacement, unless you are mounting inverted. So it would be 1 cube - .18 or = 0.82ft^3 per chamber. The sub takes volume away from the chamber.

[vetkilr01]

Exactly...sealed box to small ported as well. Mine was 1.2 after displacement sealed and 4 cubes ported with 50 squares

[soundsystemaniac]

Exactly...sealed box to small ported as well. Mine was 1.2 after displacement sealed and 4 cubes ported with 50 squares

This Is what I have come up with. 1 cubic sealed for each sub plus displacement of .18 gives me 1.18 cubes sealed per sub. 2.5 net ported at 49.xx hz with 49 sq inches of port. Do you guys think this will work?

You have to subtract the displacement, unless you are mounting inverted. So it would be 1 cube - .18 or = 0.82ft^3 per chamber. The sub takes volume away from the chamber.

Well, I worded that wrong lol. The total volume of the sealed chambers is 1.18^ft3.

[vetkilr01]

http://www.youtube.com/watch?v=KZfHFZ5VZJo&feature=youtu.be

heres a old vid of my 2 level 4s in a 4th running on a BC3500.