Loudspeaker Designs and Articles for the DIY Enthusiast
Invictus: (adj.) Incapable of being conquered, overcome, or subdued. Invincible.
Synonyms: unbeatable, unconquerable, invulnerable, unshakable, indomitable,
impregnable, unassailable, insuperable, indestructible, supreme, insurmountable,
Horizontal Polar and Off axis measurements:
Above is the modeled and normalized horizontal polar plot. It is noteworthy only in its near uniformity, only
showing the tweeter offset. Below is the actual measured responses of the Invictus every 15 degrees to 90
degrees. -Yes, I know, i left out +/- 75 degrees -Use your imagination and fill in the empty space between 60
This is another way to display the horizontal off axis response, but is measured, not modeled and
normalized as the polar plot. What is significant here is lack of off axis flare or other response aberrations.
The tonal balance and power response remain remarkably consistent, especially for a two way using a 7
inch midwoofer. This indicates a consistent tonality even far off axis, suggesting the off axis responses of
the two drivers were evenly matched.
The key for the various plot measurement angles is reproduced to the left.
Below is the same information as the plots above, but displayed as a color map. A horizontal line drawn through the center of the map would be the design
axis, or 0 degrees. Upper and lower edges are 90 degrees to the left and to the right. The color tape at the right shows the scaling of the map. Most of the
center section of the map is a redish-orange, indicating a reasonably constant response from the 0 dB point. At around 60 degrees off the design axis, the
map starts showing a horizontal bar of uniform green, suggesting the response is linear and about 6 dB down compared to the nominal 0 dB point.
Harmonic Distortion: (SPL scale is arbitrary)
The top plot is with 2.8 volts excitation. All distortion products above 100 Hz are in the 0.1% to 0.2% range.
The lower plot is with 8 volts excitation. There is some increase in 2nd order products, but they are still below 1%
|A two way design using
top shelf drivers
3 different enclosure variations