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View Full Version : Design suggestions and WinISD confirmation



lloydh
06-28-2009, 06:07 PM
Hi,

I'm designing a sub box for two 12" Alpine Type Rs to be used in a blow-through config in my single cab Dodge, powered by a PDX 1.1000.

I want to maximise SQ but am looking to a ported enclosure for efficiency and bass extension.

I put the Type R's specs into WinISD which 'recommended' a 3.8cf enclosure tuned to 26.5Hz (with a 4" diameter x 10" length port).

26.5Hz seems low compared to others' ported enclosures, but the transfer function curve WinISD produced is very flat (see below).

http://www.quicksnapper.com/files/1848/7607161034A47DC730791B_m.png

Do these figures seem reasonable?

To be honest I'm unsure of how to build a dual sub ported enclosure.

Should the two drivers have isolated chambers like a sealed enclosure and does WinISD account for this?

Presumably two chambers will require two ports but when I double the number of ports in WinISD the required port length more than doubles.

Alternatively should I treat the drivers as completely separate and use WinISD to calculate the box dimensions for one driver and one port, then when I build the box use a central divider to create 2x WinISD's calculations?

Thanks