Even in small halls, the speakers (SP) installed there have several roles. They may be the same model, but their roles are different. This page introduces what kind of roles SPs have.

Main SP + Sub woofer

This SP is responsible for the main sound output of this hall. This SP creates a "direction of sound" from the front of the speaker to the rear. This SP allows the listener to concentrate on what the speaker is saying.
​
The subwoofer is responsible for bass output. Although low frequencies are sometimes thought to impair the intelligibility of speech (especially in spaces with long reverberation times), in some regions moderate low frequencies may be thought to increase the persuasiveness of speakers.​

Sub SP

Sub SP is installed to provide rear support. This is used when the main SP alone cannot cover sufficient volume. If the venue is large, the main SP alone will not provide sufficient high frequency to the listeners at the back of the venue, making it difficult for listeners at the back of the venue to hear the content of the speech. In this case, SubSP outputs only the high frequencies, ensuring clarity for rear listeners.

Center SP

If the stage has a wide frontage, the main SP alone may not be able to provide enough high-frequency sound to the listeners in the front center. (You need a three-dimensional imagination, but with SP it is difficult to send sound directly to the side.)

If this happens, the listeners here will only hear sounds in the mid and low ranges, making it difficult for them to hear what the speaker is saying. (They have difficulty hearing even though they are close to the speaker.) In this case, the center SP is installed and outputs high frequencies for listeners in the front center.

Fill SP

If a center SP cannot be installed due to the structure or design of the hall, a fill SP may be installed at the edge of the stage. The purpose is the same as Center SP.

SP for 2nd floor

The 2nd floor is located far away from the main SP or in a recessed area, so the sound from the main SP may not reach you directly. This is a SP to complement that location. This SP basically has the same role as Fill SP, and is needed on the 2nd floor, 3rd floor, and under the balcony (the area under the 2nd floor floor on the 1st floor).

​Monitor SP

Monitor SP is different from any of the SPs mentioned above, and is an SP that allows speakers to hear their own voices. Of course, the speaker can hear the sound from the SP for the listener, but the sound lacks high frequencies and has reverberation, making it extremely difficult to hear. When speakers have difficulty hearing their own voices, they feel anxious and end up speaking louder than necessary, which can lead to fatigue. Listeners also get tired when listening to loud voices. Monitor SP is required to prevent this.

Portable

The last one is the portable SP. If the SP is not used regularly, or if there is uncertainty about where the speaker will stand, designers may want to consider a portable method. Users prepare it themselves when they need it and put it away when they are finished using it.

In this case, the designer does not need to carefully determine the location of the SP, but must consider where the SP outlet will be installed. Also, SP should not be too heavy.