Bass speakers are a kind of bass driver only used for the lowest tone part of the audio spectrum: for consumer systems, it is usually lower than 200 Hz; For professional on-site sound, it is usually lower than 100 Hz; For thx approved systems, it is usually lower than 80 Hz. due to the limited expected frequency range, the design of bass speakers system is usually simpler than traditional speakers in many aspects and usually consists of a single driver packaged in a suitable box or housing. Because the sound in this frequency range is easy to bend due to diffraction, the speaker aperture does not have to face the audience, and the bass speakers can be installed at the bottom of the shell, facing the floor. The limitation of human hearing at low frequency alleviates this problem; This kind of sound cannot be located in space, because its wavelength is larger than higher frequency, and higher frequency has a different effect on the ear due to the shadow of the head and surrounding diffraction. These two cases are the basis of our location clues.

In order to accurately reproduce very low bass without unnecessary resonance (usually from the cabinet panel), the bass speakers system must be firmly constructed and properly supported to avoid unnecessary sound caused by cabinet vibration. Therefore, a good bass speaker is usually quite heavy. Many bass speaker systems include integrated power amplifiers and electronic subsonic filters, as well as additional controls related to low-frequency reproduction (e.g., cross knobs and phase switches). These variants are called "active" or "active" bass speakers, the former including a power amplifier. C bass speakers and "passive" bass speakers require external amplification.

In a typical installation, the bass speakers are physically separated from the rest of the

loudspeakers cabinet. Due to propagation delay, their output may be slightly inconsistent with the phase of another bass speaker (on another channel), or slightly inconsistent with other sounds. Therefore, the power amplifier of the bass speakers usually has phase delay adjustment (about a 1-millisecond delay is required for each additional separation foot from the listener), which may improve the overall performance of the system at the bass speakers' frequency (maybe an octave above the intersection). However, the influence of room resonance (sometimes called standing wave) is usually large, so in practice, such problems are secondary. Bass speakers are widely used in the sound reinforcement system of large concerts and medium-sized venues. Bass speakers usually have a bass reflection port (that is, a hole is made in the speaker and a pipe is connected). If properly designed, this design feature can improve bass performance and efficiency.</