The lower numbers are associated with the lower bass frequencies while the higher numbers represent the higher treble frequencies. Optimal human hearing is about 20Hz to 20,000Hz. The closer a frequency response meets that range, the more likely that the sound output is accurately reproduced. Of course, better speaker systems are likely to offer more faithful frequency responses and music qualities. Some models may also work with batteries, for portability.
Images are for visual reference only.
Not all accessories pictured are included. Not responsible for typographical errors.