R. J. Barny Hiney CET P. Eng. ( BC Pndg.)
e-mail: hiney@bc.sympatico.ca
Las
Vegas Nevada, USA 89103
ATTN:
Josef Tyls Vice-President
of Engineering
Dear
Josef Tyls:
This
report will summarize the tests performed on the Holosphear 4D Mark IIIc
speaker system and MANIFOLD at your workspace in North Vancouver, British
Columbia, on May 6, 1999.
The
system under test and review was the Speaker System intended for use with the
Live and Theatre Entertainment System presently under development by
Holosphear 4D. The frequency
response and audio power tests were verified and conducted on the fabricated
speaker units. The tests were
intended to verify the efficiency and wide dynamic range of the speaker
system. One model of each type
was tested with the listed measuring equipment and the results recorded. Multiple models were compared, the comparisons verified, but
no data was recorded. Technical
details of the units were not provided. The
units are manufacturing prototypes and are to be exactly reproduced in
production.
The
tests were conducted in the audio test and control workshop located at the
above address. The data was
recorded and verified against specifications.
The data was compared to specifications and was not graphed or
analyzed, as there was correlation between specifications and the recorded
data.
The
frequency and ouput power data recorded during this test session were
sufficient to verify the operation of the units against the specifications
provided. If these prototype
speaker systems are reproduced in manufacturing they will meet the stated
specifications.
Please
find the test procedures and results on Page 2/.
If
there are any questions regarding the contained information please contact the
writer.
Yours
truly,
R.
J. “Barny” Hiney
Please
find below the Test Configuration, Instrumentation and Recorded Data:
The
test setup included high quality audio power amplifiers, low resistance/high
power copper leads and 100 watt load resistors of 5.25 ohms. Measured by Micronta #22167
-
CD-ROM player and various sound track diskettes
Measuring devices were as follows:
-Pink
Noise, power output voltages- 3 ˝ Digit PROTEK 506-Dual Slope Voltmeter
-Oscilloscope
monitoring of sine wave output sine wave and amplitude
-Sound
Level Meters
The system was set up near the rear wall of the audio room and the sound
level meters placed 1 meter from the speaker system.
The Pink Noise source was adjusted and level set, averaged over 10
seconds, for an output of (.920 to 1.012 Volts) producing an audio output
level of 88 dB. The output was
standardized at 1kHz at 87 dB ( 1.012 Volts).
The results for the Holosphear 4D Mark IIIc speaker system are as
follows:
30 Hz
66 dB
@ 1.005 Volts
35 Hz
72 dB
@ 1.009 Volts
60 Hz
83 dB
@ 1.017 Volts
70 Hz
86 dB
@ 1.018 Volts
1
kHz
87 dB
@ 1.012 Volts
12 kHz
87 dB @
1.012 Volts
17
kHz
81 dB @
1.004 Volts
20
kHz
68 dB @
1.009 Volts
The system was set up near the rear wall of the audio room and the sound
level meters placed 1 meter from the speaker system.
The Pink Noise source was adjusted and level set, averaged over 8
seconds, for an output of (.800 to 1.102 Volts) producing an audio output
level of 86 dB. The low frequency corner is 35 Hz.
The results for the Holosphear 4D MANIFOLD speaker system are as
follows:
16 Hz
58 dB @ 1.008 Volts
20 Hz
66 dB @ 1.008 Volts
25 Hz
70 dB @ 1.001 Volts
30
Hz
81 dB @ 1.001 Volts
35 Hz
87 dB @ 1.008 Volts
40
Hz
86 dB @ 1.003 Volts
80 Hz
95 dB @ 1.001 Volts
The Crossover network functions @ 90 Hz and was operational.
Various frequencies throughout
the spectrum were measured to ensure and verify flat response. There were no
exceptions or anomalies and data was not recorded.
A demonstration of
performance was provided and the system performance was excellent.