Frequency response of Pleiades linoleum tetrahedron speaker made by Vicky

Signal path:


Alan Parsons test CD 1/3oct bands - Sony CD Player - JVC radio amplifier 9425W - linoleum tetrahedron speaker - linoleum carpet 1m x 2m - wooden floor - non reverberant bedroom - Bruel and Kjaer 2209 at more than 2 ft from speaker


The frequency response is much much worse than expected. The linoleum autatone 5C type speaker measures much much better. A possible cause may be difference of drive unit since so far 2 tetrahedron speakers with same batch Tesla speaker sound very different. Large air gaps as tetrahedron is not glued yet. Or cube gives much better frequency response with such drive unit. The strange thing again is that the pyramid sounds better. And that the mid frequency content that the cube radiates at sides does not sound good. Another auestion is whether the pyramid should have a different volume. Perhaps same volume as cube? Also whether wooden enclosures be compared to linoleum ones, baffles of either material etc.


The linoleum Auratone 5C type cube has a response of + or - 3dB from roughly 100Hz to 14KHz which is very good.
This was measured in a different room a reverberant one. See older posts.


It has also to be noted that these measurements are done more or less on axis of drive unit. It may be that the pyramid has a more uniform frequency response at other angles than cube at other angles. This measure to has not been tried yet.


Here is a rough frequency response of the linoleum tetrahedron.


20Hz
25Hz
31.5Hz
40Hz
50Hz
60Hz  -15dB
80Hz -10dB
100Hz -6dB
125Hz -6dB
160Hz -10dB
200Hz -7dB
250Hz -3dB
315Hz 0dB
400Hz 4dB
500Hz 3dB
630Hz -4dB
800Hz -10dB
1KHz -3dB
1.25Hz 1dB
1.6Hz -2dB
2KHz -6dB
2.5KHz -10dB
3.15KHz -8dB
4KHz -8dB
5KHz -6dB
6.3KHz -3dB
8KHz +1dB
10KHz -3dB
12.5KHz -15dB
16KHz -15dB