Elenco AM/FM Radio Kit - Manual (Page 62)

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2. Bend the four flaps upward as shown.
1. Start at one edge and carefully remove the
baffle from the bottom the kit box.
brown
side
AM/FM-108CK Kit Carton
AM/FM-108 Radio Baffle
NOTICE: Keep the box the kit came in. After you
have completed the radio and it operates
satisfactorily, you may want to install a
baffle to improve the sound.
The final step in the radio kit will be to assemble and
attach a baffle to the speaker. You will need to
remove the baffle located in the bottom of the box. If
it does not want to come out easily, use a knife to cut
the holding tabs.
When a speaker is not enclosed, sound waves can
travel in all directions. As a speaker moves outward,
it creates positive pressure on the air in front of it and
negative pressure on the rear. At low frequencies,
out of phase front and rear waves mix causing partial
or total cancellation of the sound wave. The end
result is a speaker less efficient and distorted.
To eliminate the low frequency cancellation, a
speaker is placed inside an enclosure. Now the front
sound wave are prevented from traveling to the back.
The speaker will now compress and decompress air
inside, increasing its resonant frequency and Q
relative to the free air values. This type of effectively
air-tight box is called an Acoustic Suspension.
2 Screws M1.8 x 7.5mm
2 Nuts M1.8
Baffle