Wisdom Audio DCAB-1 - Manual (Page 32)

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Boost the Bottom of the Planar Ideally, we would like the planar magnetic portion of the speaker to reproduce
as much of the music as it can. Fortunately, these incredibly robust drivers can
handle a bit of equalization to help them reach a bit lower than they would in
the absence of EQ.
In most rooms, you will see that the response of the planar section is rolling off
a bit before it reaches the crossover frequency. Use your first boost filter to bring
the response of this region up to match the average levels you established in the
last step (50–150 Hz and 300 Hz–10 kHz). (The default settings from the factory
should get you close; feel free to modify them to suit the needs of the system in
your particular room.)
Start by choosing a center frequency that is roughly halfway between the cross-
over frequency you selected and the point at which the planar section begins
to roll off. Then add perhaps 5-6 dB of amplitude. You will then have to reduce
the Q of boost 1 to affect a wider range of frequencies. (A Q of 100% is an ex-
tremely narrow spike that is hard to see on a
1 ⁄
3
-octave analyzer, and too narrow
to serve your purpose here.) As you lower the Q from 100%, you will see the
effect of the boost spread out in frequency and increase in amplitude.
Fine-tune the three parameters until the lower end of the planar section’s re-
sponse is fairly smooth and contiguous from the crossover frequency up to
approximately 300 Hz. Remember: Frequency moves the boost left or right in
the RTA Display; Amplitude increases or decreases the size of the boost; and
Q changes the width of the area affected (as well as modifying the amplitude a
bit).
Don’t worry about making this perfect yet. Just make it better. You will refine all
settings later, once things are smoother and small errors are easier to see.
Cut the 5-7 kHz peak The nature of all double-ended planar magnetic drivers is such that there is in-
evitably a peak in the response at approximately 5-7kHz. This is a result of the
sound being forced between the front magnets on its way to your ears. Correct-
ing this characteristic is the next step in calibration.
Use your first notch filter much as you did your first boost filter, except that you
will be removing a peak instead of filling a dip.