Loudspeaker Designs and Articles for the DIY Enthusiast
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The plot above is the modeled and normalized
vertical polar plot. As expected for an MT design,
there is some minor non-symmetrical about the
vertical plane. Most notably the nulls at -32
degrees and 25 degrees above the design axis.
These are far from the normal listening angles and
will present no issues in normal listening.
The summed frequency response is relatively flat,
and as is my penchant, is slightly tilted, with the
tweeter being about 2 dB below the midrange
level. Frequencies below 200 Hz are not shown as
they are below the accuracy limits of my
Not much to say here except I wish all my designs
came out looking this good. Keep in mind the
vertical lines are just a artifact of the plot. The
phase rotation actually continues downward, but at
the limits of the chart is switched up 360 degrees
so it can be easily displayed. The fact the phase is
almost perfect at the phase wrap makes for a nice
looking plot, but is not any more important than
any other frequency either side of it.
As you can see from the MLTL impedance plot,
this truly is an 8 ohm design, actually spending a
significant portion of the pass band above 10
ohms. The impedance minima is roughly 7 ohms
and the worse case impedance/phase is at 55 Hz
with the phase at -55 degrees, and 13 ohms.
-MLTL impedance shown.
|A two way design using
top shelf drivers
3 different enclosure variations
Modeled low end response:
MLTL response is in red
Sealed in Magenta,
Infinite baffle in Blue (Qtc = 0.5)
Sealed F6 = 40 Hz F9 = 30 Hz
MLTL F6 = 21 Hz.
The response is down 1.5 dB at 30 Hz.