An introduction to Hi-Fi Systems. Part 2: Loudspeakers
Making music come to life
Loudspeakers are the end of the chain in a Hi-Fi system. After the signal has passed through the source, the cables and the amplifier(s), the loudspeakers convert electrical signals to sound pressure. As with everything in high-end Hi-Fi, this has to be done on the best possible manner for the music to sound as realistically as possible. But what is important for a loudspeaker to be able do so? Apart from the more common defining qualities of a loudspeaker like the quality of the drivers and the crossover, there are aspects that are less obvious but equally important to consider if you truly want to get the best out of your Hi-Fi system.
Going the extra mile
Acoustics & diffraction
The acoustics of your room are the starting point when choosing a loudspeaker. Acoustics signficantly impacts listening experience. Even the best loudspeakers can sound dull if the acoustics of the room are poor or if the loudspeakers and the room simply do not 'match'.
When sound waves hit a sharp edge, slit or holes, they tend to bend around it. This is called diffraction. If this is not properly controlled, in some rooms the effects of diffraction become audible, negatively impacting the listening experience. The highest quality speakers are designed based on a process where diffraction is predicted and controlled.
Dispersion
Dispersion is the direction in which the sound from a loudspeaker radiates. The dispersion of a loudspeaker varies with different frequencies. At lower frequencies, where the bass portion of the music is dominant, a loudspeaker directs sound more equally in all directions. As the frequencies increase, sound is more and more focused towards the axis of the drivers. The science behind this have to be incorporated in the design process when choosing the placement and angles of the drivers on the cabinet.
Apart from loudspeaker design, cables influence the dispersion pattern of a loudspeaker too. Matching your cables with your loudspeakers carefully can have a significant effect on the performance of your system.
Cabinet resonance
The movements and vibration of drive units produce music. This is basic loudspeaker design. But, for every movement or force, there is a reaction force that comes with it. When a drive unit moves to produce sound, an amount of force is sent back to the driver in the cabinet. As a result, the cabinet can vibrate as well. Vibrations of the loudspeaker cabinet can cause resonance and unwanted noise, which decrease the sonic performance of your system. Controlling this is one of the most important factors in loudspeaker design. Proper design significantly improves sound quality.
Internal wiring
When the electric signal enters into the loudspeaker, the signal is converted into music, it travels through the loudspeaker via the wiring inside the cabinet. Therefore, high quality wiring is essential to ensure the best signal transfer. People often go to great lengths to optimise the cabling of their system to get the best out of it, but forget to consider the internal wiring of their speakers. A lot can be lost by having bad wires in your loudspeakers.
Details matter
There is a lot more to loudspeakers than what meets the eye. Small changes in the choice of materials, room acoustics or even small vibrations of the loudspeaker cabinet can significantly affect the sonic performance of a hi-fi system . That is why it is important to look further than basic loudspeaker design when you truly want to get the best out of your system.
