Woofer speakers, also known as bass speakers, are devices that can handle low to low-mid frequencies within the audio spectrum. The word woofer derives from the sound that dogs produce when they bark. The frequency range of woofer speakers is set between 40Hz and 500Hz. It’s worth mentioning that the lowest frequency sound that the human ear is able to hear is 20Hz. Woofers tend to cover the lowest octaves of a loudspeaker’s frequency range, whereas, in two-way loudspeaker systems, the drivers also cover the mid-range frequency. The midrange frequency is usually set between 2,000Hz and 5,000Hz.
Subwoofers are a type of woofer that is designed to cover extremely low-frequencies. Subwoofers are commonly used in home theatre systems as well as in PA systems. The aim of these types of woofers is to increase the bass response. Subwoofers are set to frequencies between 20Hz and 120Hz.
There are several types of woofer speakers, such as standard woofers, subwoofers, mid-woofers, and rotary woofers. In essence, they are all built in the same way, but they have some differences as well.
Standard woofers have a unique sound that is derived by the lower frequency sine wave. Standard woofers are an essential part of higher-end speakers that might contain a woofer and a tweeter, or a woofer, a tweeter and a mid-range speaker. Standard woofers produce frequencies between 20Hz and 2,000Hz.
Subwoofers involve one or more woofers that are held inside a wooden container. The sound produced by subwoofers is mostly felt, now heard, since the human ear is only able to perceive frequencies as low as 12Hz, and these devices can only produce tones lower than 200Hz. Subwoofers are typically used as add-ons to consumer speaker setups. These devices are usually isolated and provide a low-level beat.
Mid-woofers have the best quality sound since they land just in the middle of the woofer range. These types of woofers are set to frequencies between 200Hz and -5kHz, so when they reach either end of the spectrum, the quality of the sound begins to deteriorate.
Rotary woofers use the coil’s motion to modify the pitch of fan blades. Since the pitch of the blades is altered by the audio amp, the power required is much less than that of a conventional subwoofer. Rotary woofers can produce sounds below 20Hz and easily reach 0Hz. It’s worth mentioning that such low frequencies cannot be heard by the human ear.