A loudspeaker, speaker, or a speaker system is an electrical device that can convert electrical signal into sound. They are the most invincible part in audio system and have the capability to produce different and distinct sounds that make music more audible.

The history of the speakers probably started in the year 1876 when Alexander Graham Bell patented the first electrical loudspeaker. From then until 1950 the standard of the speaker was poor if we compare them to the modern one.

To reproduce a wide range of frequencies loudspeaker system requires more than one driver either for high sound pressure level or high fidelity applications. Continuous research, development and revolution in technology have led to a wide variety of improvements like improvements in cone materials, introduction of higher temperature adhesives, improved permanent magnet materials, improved measurement techniques, computer aided design, and finite element analysis, thus leading to noteworthy audible experience.

Choosing speakers is one of the most important tasks while setting up any audio or video system. It is very important to know where the speakers are going to be placed because different rooms have different requirements. Large room speakers require more power in order to output high volume levels without distortion, so one need larger amplifiers for large rooms or more efficient speakers. While making the choice, some points should be kept in mind like balance and frequency range, fine tuning, speaker types, etc.

The term frequency range defines how accurately the speakers can play the highest and the lowest frequency. We may come across some speakers that sound bombastic on a high frequency song while the same becomes almost inaudible at low. A good pair of speakers have the brilliance to strike the right balance and play each sound at the accurate level.

If the frequency range is poor and the balance is not maintained, the sounds tend to become fuzzy or rough when the volume is increased. At the same time the speakers cannot play sounds at low volumes after reaching a certain point. Some speakers will play sounds alike and do not distinguish between soft and harsh tones.

The best way to test the neutrality of the speakers is to play in a recorded human voice. If the recorded voice sounds just the way it does in real life or sounds as if the individual is speaking in just one tone then the speaker is definitely well balanced and has a good frequency range. The balance control not only changes the relative volume of the speakers, but also delays the sound from the speaker closest to the ear so that all the sounds can reach the ear at the same time.

If we talk technically about the balance and frequency range of the speakers directivity becomes an important issue because it affects the frequency balance of sound the listener hears and also the interaction of the speaker with the room. Directivity measures the power density that an actual antenna radiates in the direction of its strongest emission. A loudspeaker with a high degree of directivity can be said to have a high quality.