Of all the components in the system, portable Bluetooth speakers are the most likely to fail. The most common problem is a driver crash, usually when twitter stops working. Tweeters are often damaged by excessive current flowing through their voice coils. The tweeter cannot emit the heat quickly enough, and its voice coil is burned.

Another common cause of speaker failure is buzzing caused by loose voice coils. The current passing through the voice coil will melt the glue that fixes the voice coil on the voice coil. This will loosen the number of turns of the wire, and then the wire will rub against the magnet to produce a buzzing sound.

The mounting bolts of the driver will loosen over time and make the whole driver vibrate, not just its diaphragm, thereby reducing the performance of the speaker. Gently tightening these bolts from time to time, especially when the speaker is new, can improve its sound. Be careful not to over-tighten and peel the bolts.

The dynamic driver I described eventually violates the laws of physics. Specifically, the intensity of the magnetic field generated by the fixed magnet is limited, which in turn limits the weight of the cone, the playback frequency of the driver, and the sensitivity of the driver. The heavy cone has a lower frequency (all other factors are the same) but requires greater magnetic field strength around the voice coil to drive. These limitations are particularly severe in large subwoofers.

The solution to this physical problem is an electromagnetic driver (also known as a field coil driver), in which the fixed magnet of the driver is replaced by a large coil used as an electromagnet. The coil is driven by DC from the external power supply plugged into the AC socket. The current flowing through the coil generates a magnetic field, which is pushed and pulled by the magnetic field generated by the voice coil. The magnetic field intensity generated by the electromagnet in the gap (the area where the voice coil is located) is almost twice that of the traditional drive wireless Bluetooth speakers.

Therefore, the electromagnetic bass speaker can be heavier (making it have a lower resonant frequency), but at the same time, it is more efficient. In addition, the bass output of the woofer can be adjusted by changing the current through the solenoid. This is achieved by controlling the external power supply that drives the current through the solenoid. Therefore, the bass output of the electromagnetic woofer can be adjusted to better integrate the system into various listening rooms.