However, in this example, there is one prob-
lem...our low point is far below the actual width
of our desired curve, thus even the flat portion of
the UFW’s desired response will be attenuated.
To avoid this, we need to move our center point
up just a bit, such that it is closer to equidistant
between our “beginning” and “end” points. In
other words, if we move our center point up from
45Hz to 55Hz, our “end” point of 80Hz is now
only 25Hz above our center (instead of 35Hz),
and our “beginning” point is now 30Hz below
our center (instead of 20Hz). Because we must
be equidistant from this center frequency, our
range thus becomes 25Hz to 85Hz—much closer
to our desired value. In addition, because the
system will likely be crossed over at 80Hz, the
additional attenuation above the actual curve will
not affect the UFW’s response.
Now that we know how far above and below we
need our width points, we must calculate the
percentage of a full octave this translates to.
This can be done with the following equation:
[(Bandwidth)x(Center Hz)] + (Center Hz)
Which breaks down to:
Bandwidth(B) = High Cutoff(H) - Center Hz(C)
Center Hz (C)
Thus, in this example, we substitute our points
as follows
(B) = (H) 85Hz - (C) 55Hz
(C) 55Hz
And, finally, we have B = 0.55. In other words,
the bandwidth dial should be adjusted to 0.55 in
order to set a curve width between 25Hz and
85Hz on a 55Hz center point.
C) Level—Now that we’ve defined our peak’s
width, we move on to the goal of this exer-
cise...to flatten it out. For this, we need to de-
cide how much boost or cut will be necessary.
In our sample data, our center frequency (55Hz)
corresponds to a gain of right about 74 dB.
However, as you can see in the above figure, the
rest of our curve is flat at about the 69 dB level.
Thus, in this example, a 5dB cut applied to our
curve will sufficiently “tame” this peak and flat-
ten the response of the UFW-10 in your room.
NOTE: After the filter is set, we recommend per-
forming a new frequency sweep to check results
and to identify where to make fine tuning adjust-
ments.
30
50
80
20
New Center
(55Hz)
Actual Curve Width
25Hz
85Hz
30
50
80
20
Center
(45Hz)
Actual Curve Width
10Hz
80Hz
30
50
80
20
68
74
70
72
Hz
(C)
Figure 5.5
Figure 5.6
Figure 5.7
