Measurements for Soundcare SuperSpikes
The
measurement:
A
calibrated loudspeaker has been fed with a sinus wave on each frequency level.
The loudspeaker has been places upon a calibrated pressure sensitive microphone.
For each frequency the signal is fed through the loudspeaker and the output
level is adjusted to specific level which is referred to as 0 db.
Then
the spike is placed between the loudspeaker cabinet and the pressure sensitive
microphone. The same signal with the same output level is used. The level from
the microphone is then measured. The direct sound through air from the
loudspeaker to the microphone is never measured louder than –30 db for any of
the frequencies. The curves will therefore show the approximate transport of
energy from loudspeaker cabinet through the spike and down to the microphone.
In words the damping of acoustic feedback is:
|
50
Hz
-11 db 100Hz
-10 db 150Hz
-6 db 200Hz
-1 db 300Hz
-6 db 400Hz
-3 db 600Hz -3 db |
800Hz
-1 db 1600Hz 0 db 2500Hz
0 db 3200Hz
-5 db 6400Hz -2 db 9600Hz
-2,5 db 12800Hz -3 db |
We do
not know of any other that has measured spikes this way before. Until now spikes
only have been listening tested as far as we know. This is a way to try to
measure the benefits in a way that makes it possible to show the results on
paper. There can be inaccuracy because of unknown resonances and other unknown
influence, but we are sure these results show how spikes reduce acoustic
feedback.
The different models, threaded and self-adhesive have been tested. The results are so similar for the different models that it does not influence the curve.