Eminence Kappa12a reflex tuning

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   Hello Everyone!
I would like to build a pair of cabs, for 2 Kappa12a and 2 PSD2002-8 that i already have at home.
I developed a project for a 60 liters box, that's more or less the maximum volume indicated for the woofer (considered the volume taken by the woofer itself, the hf driver+horn and the damping material, i thought that it would work well)

My problem is: I don't know how to calculate the reflex port size and depth

My requirements are..
1) Port shall be of rectangular shape, 350mm wide (cab's whole internal width) with a 15mm brace panel in the middle (so maybe port is to be considered 335mm wide.. isn't it?)
2) 50 / 55hz tuned.
Kappa12a starts to loose efficiency in response under 70hz, i would like to enhance low frequencies in order to gain some bass.

I tryied to use some "reflex automatic calculator" on the internet, but seriusly i don't get any understandable result. I'd rather learn how to calculate it by myself.
Would someone help me with this?

Best regards

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sushi Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 27 March 2012 Location: Milan Status: Offline Points: 90	Post Options Post Reply Quote sushi Report Post Thanks(0) Quote Reply Topic: Eminence Kappa12a reflex tuning Posted: 22 January 2020 at 4:15pm
	Hello Everyone! I would like to build a pair of cabs, for 2 Kappa12a and 2 PSD2002-8 that i already have at home. I developed a project for a 60 liters box, that's more or less the maximum volume indicated for the woofer (considered the volume taken by the woofer itself, the hf driver+horn and the damping material, i thought that it would work well) My problem is: I don't know how to calculate the reflex port size and depth My requirements are.. 1) Port shall be of rectangular shape, 350mm wide (cab's whole internal width) with a 15mm brace panel in the middle (so maybe port is to be considered 335mm wide.. isn't it?) 2) 50 / 55hz tuned. Kappa12a starts to loose efficiency in response under 70hz, i would like to enhance low frequencies in order to gain some bass. I tryied to use some "reflex automatic calculator" on the internet, but seriusly i don't get any understandable result. I'd rather learn how to calculate it by myself. Would someone help me with this? Best regards

smithshorn Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 08 February 2007 Status: Offline Points: 253	Post Options Post Reply Quote smithshorn Report Post Thanks(0) Quote Reply Posted: 22 January 2020 at 5:06pm
	Winisd is your friend here. Probably the simplest calculator out there. Ports can be calculated for round, or square/rectangular as well.

Conanski Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 January 2006 Location: Ottawa, Canada Status: Offline Points: 2543	Post Options Post Reply Quote Conanski Report Post Thanks(0) Quote Reply Posted: 22 January 2020 at 5:45pm
	Download a copy of Win ISD and run a simulation.[URL=http://www.linearteam.org/ If that driver isn't already in the program(I think it is) you will have to enter the TS specs as a new file. And I suggest you don't try to get too much lowend out of those drivers, they're designed more as low/mid than a bass driver.

sushi Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 27 March 2012 Location: Milan Status: Offline Points: 90	Post Options Post Reply Quote sushi Report Post Thanks(0) Quote Reply Posted: 22 January 2020 at 9:53pm
	Thanks a lot! I'll try to download it on my pc, hope it will solve my issues. I won't try to get a sub from the cab, just looking for a near-fullrange performance for small indoor parties.. i've been using the kappa12a for years in a sealed cab and i know it has its limits. I'll surely put an highpass filter at 50hz. Gonna use my 18" reflex cabs if i need loud bass.