18
Figure 24 shows mechanical views of the 3635 subwoofer, which is intended for use with the other models
in the 3000 Series product group. The 3635 subwoofer has a useful lower frequency limit of 28 Hz (- 3 dB), as
compared to 18 Hz for the 4645C. The power rating of the 3635 subwoofer is 300 watts, as compared to 800 watts
for the 4645C. One is clearly not a substitute for the other, so specify accordingly. The 3635 is intended for use
only in small room applications with the other members of the 3000 Series family.
F. Surround Requirements:
As a general rule, the total ensemble of surround loudspeakers should be capable of producing as
much acoustical power as a single screen channel. Today, the JBL 8340A surround loudspeaker is capable of
producing total acoustical power output in the range of about 2 acoustical watts. Since a typical dual woofer
JBL screen loudspeaker is capable of producing continuous acoustic power output of 28 watts, it is clear that
14 of the 8340A’s will be required for power matching. Typically, in a large house, 12 to 16 units will suffi ce. The
careful designer should not specify less than this quantity. In smaller houses a similar quantity of 8330A’s may be
specifi ed. The 3310 surround is normally specifi ed in smaller spaces as a complement to the other systems in the
3000 Series. The specifi c arraying of surround loudspeakers will be covered in Section V-C.
Several views of the surround models 8330A, 8340A are shown in Figure 25A and 3310 are shown in
Figure 25B.
Figure 23: Front and side drawings of 4642A subwoofer.
Figure 24: Front and side drawings of the 3635 subwoofer.
Figure 25A: Front and side drawings of JBL surround loudspeakers. 8330A and 8340A (A); 3310 and 2502 bracket (B).