Attenuation vs Frequency


	The following tests were done with the same setup as
with the Resonance vs Stuffing materials page. I wanted to
get the attenuations effect inside the speaker box.


				Table 2

.....................................................................

	Freq.      Polyesters        Wool     Cotton    Fiberglass    Foam
	           1       2     3       4        5          6           7

	50 Hz.     .54     2.5    2.73    .82      .63        1.83      3.35
	250 Hz.   5.19     6.02   6.02   3.88     5.68        7.33      8.18
	800 Hz.   9.63    10.17  10.17   6.38    12.77       13.98     12.77


	
	All values were made with 8 oz. stuffing inside the 1280 cu.in.
box. There was acertain amount of inaccuracy during actual measurments
which I would attribute to various effects such as, more than one path
to the microphone. Call it phasing errors due to reflections, varying
with frequency. I had to somwhat smooth out the table as seen on a
line graph. The low 50 Hz attenuation of low grade polyester and and cotton I
would attribute to their low lofting qualities, allthough it
performs nicely as a effective low pass filter.


					End