Hi Jim
Yes, correct if you want to hear the sound coming from the speakers. In the
case of my project, you don't want to hear the sound coming from the
speaker.
It is necessary to carefully adjust the audio level to minimum necessary to
cause the column of air to oscillate. It is easy to overdrive the CW
speaker.
I can measure the SPL 1m in front of the speaker without the pipe and with
the pipe, the net gain is 10 db SPL, the box and the tube change the SP.
The position of the CW speaker is vertical and far from the listening
position, firing up,. Or down in the case of my desk, I don't want to hear
audio from the speakers at all. Think about a organ pipe. The final adjust
in level is tune a strong signal and reduce the AF gain, most case 10 db
below the normal level.
My listening position is in the center of the radio. 2 FT from the right CW
speaker, and 2 FT from the left speaker. The speakers are separates near 3
FT.
Adrian is using one tube open both ends, and he did a great job sealing the
speaker box using absorbent material, so you don't hear the sound coming
from the speaker. The box has a second open speaker so you can switch to
listing without the tube. The pest position to listen to Adrian CW speaker
is 2 to 3 FT from the pipe. Firing on the sides, not at you.
73's
JC
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