CONNECTIONS |
| SETUP SUGGESTIONS |
|
|
|
The two 1/4" phone jacks on the 115sA/118sA are wired in full parallel so that any one of the connectors may be used as an input and the other connector as an output to another enclosure. This allows multiple cabinets to be "daisy chained", eliminating the need for several long runs of speaker cable.
Note: A single 115sA/118sA subwoofer represents an 8Ω load to the amplifier. Daisy chaining two of them in parallel will represent a 4Ω load to the amplifier. Only amplifiers rated for 4Ω output should be used in this configuration.
The following polarity convention should be used when making connections to the 115sA/118sA:
Polarity | Phone Jack |
Positive (+) | Tip |
Negative | Sleeve |
USING THE 115sA/118sA IN A SYSTEM
The 115sA/118sA is designed to augment the low frequency performance of the main P.A. speakers. The single reflex bandpass design of these systems automatically rolls off the high frequencies eliminating the need for an active or electronic crossover network. Thus, the subwoofers can be wired directly in parallel with almost any
Nonetheless, a
Two different configurations are shown on pages 5 and 6, demonstrating how easy it is to add a subwoofer to your system. Figure 3, on page 7, shows a more extensive configuration for those set- ups requiring additional power.
The placement of any speaker can dramatically affect its sound. Thus, there are three primary considerations to review when placing subwoofers.
The first is time alignment. The
The second consideration is to try to obtain as much bass as possible from the subwoofer. A speaker in the middle of the floor or up in the air with its back against a wall is referred to as operating in "half space". Placing a speaker near a large, flat wall and on the floor (quarter space) will boost the bass performance by about 3 dB as compared to half space. The more surfaces the subwoofer is placed against, the fewer the number of subwoofer enclosures are needed to achieve a desired SPL.
The third consideration is convenience and the visual aspect of the speaker array. For temporary installations, the subwoofer can be used as a support for a
For each particular situation, a compromise among these three factors should yield the best solution possible.
4