March 14, 2012

Will this driver work down-firing?

Some drivers are fine in a downfiring orientation, others aren't suitable. It depends on the stiffness of the suspension. A downfiring orientation can cause the cone to sag, resulting in a loss of excursion and output.

Sag = Cms x mms x 9.8

mms is in kg

The sag should be less than 5% of driver xmax


  1. Timely. I'm about to build a small downfiring LT sub, and I was wondering about sag.


  2. I used this calculation before building my downfiring subwoofers.

    A little bit of additional background reading for anyone interested in an adireaudio whitepaper

    Only place I can find it hosted now is here -

  3. You can find just about any old website at the Way Back machine:

    Just search for

    Look at the pages around 2003. You'll find any Adire info that they had in the past.


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