In this article, I’m trying to give an overview of some commonly used loudspeaker designs. Almost all speakers which are on the market these days are based on similar designs. However, obviously manufacturers are tweaking the looks of the speakers in order to attract more customers. However, the basic principle remains the same.
Probably one of the most commonly used designs in loudspeaker manufacturing is the Bass reflex box. This type of loudspeaker usually contains two transducers as well as support. A port is of four which is punched into one of the walls of the loudspeaker enclosure. In case of the Bass reflex box, this port is provided at the front of the loudspeaker. The low-frequency components which are generated by the woofer are reflected by the rear wall of the speaker and then gets to the ports and exit towards the listener.
Bass reflex boxes can achieve fairly good low-frequency response without being very bulky. Low-frequency response is probably one of the biggest challenges in loudspeaker design. The fact is that normally speakers do not have good response at the low-frequency region unless they contain a large amount of volume. However, large speakers are not easy to move and install. Another design which minimizes the volume beaker while still providing for adequate low-frequency response use internal tubing. The sound waves are guided through these waveguides and then exit what’s the listener. This tubing emulates a large enclosure.
Entry-level loudspeakers usually don’t have a dedicated port and simply contain one or two transducers. As an example, wireless Bluetooth speakers usually have one single transducer for each channel. Therefore these types of loudspeakers don’t excel at reproducing low frequencies.
Also, in most cases home theater speakers don’t have a special low-frequency port. That is made up by the fact that these theater kids come with a dedicated subwoofer. However, if you want to purchase speakers for listening to music then a home theater system is usually not the best option since oftentimes it is lacking in high frequencies.
The way that the transducers are mounted inside the speaker differ between different designs. Most commonly, all transducer mounted to a single wall. However, some speakers mount the woofer vertically. This results in sound exiting towards the top or bottom of the speaker. However, even though this design is a good option for omnidirectional sound distribution, the mid range will be lacking the cost it is radiated mostly towards one direction. The way that manufacturers overcome these challenges by providing a part right in front of the transducer which is designed to reflect these mid frequencies in all directions.