How long speakers last depends on the quality, maintenance, and environment. Quality speakers that are used responsibly may last for decades. Their high-quality circuitry, switches, and other speaker components have a lower chance of breaking down. However external factors are also important such as maintenance, repairing parts on time, and cleaning regularly. Lastly, the environment such as rooms with a lot of moisture may reduce the life of a speaker.
Materials and Build Quality
The build quality and materials have the greatest impact on the longevity of a speaker. Cheap plywood enclosures are prone to damage. Medium-density fiberboard (MDF) is a common choice, as it is relatively durable. However, wood can start to rot or develop mold growth when left in a humid environment. Plastic does not rot but lacks the acoustic properties of a wood enclosure.
The quality of the capacitors also determines the service life of the speakers. Standard capacitors have an average life of 10 years. The top manufacturers tend to use premium capacitors, which are less likely to break down over time. High-quality capacitors may last 20 years or longer.
Speakers with multiple drivers contain a crossover circuit, which uses combinations of capacitors and resistors to filter the input signal into different frequencies. Active speakers have built-in amplifiers with capacitors and resistors. Capacitors are mostly used in the amplifier to isolate the DC signal from the AC signal and prevent electromagnetic interference.
Most speakers contain electrolytic capacitors, which contain an oxide layer that acts as an insulator for handling high voltages. As the oxide layer deteriorates, the voltage capacity decreases. Worn capacitors can lead to a variety of issues with speakers. If the capacitors used near the inputs on the circuit go bad, you may notice increased interference and static.
If the capacitors used in the crossover circuit deteriorate, the frequency range of the filter changes. More of the signal may go to the tweeters or the woofers. Luckily, you can replace capacitors and extend the life of a speaker.
The surround is the component that is most likely to deteriorate. It holds the speaker cone to the frame. Speakers from the 1950s and 1960s were made with cheap foam surrounds that broke down quickly. Modern rubber surrounds should last decades but are also replaceable.
Environment
Damp, humid environments are not good for electronics. If the environment is too humid, moisture may collect around the panel and plugs, which may damage the speakers and connected components. Extreme cold and fluctuations in temperature are also bad for your speakers. When using electronics in below-freezing temperatures, moisture may form around metal components.
Another common concern is smoke, which can negatively impact any electronics in the room. Smoke from cigarettes and other substances can create resiny, brown buildup inside electronic devices, including speakers and your amplifier. The accumulated debris is difficult to clean and may eventually cause metal components to corrode. If you smoke indoors, consider using an air purifier to help protect electronics.
Usage
The way that you use and treat your speakers impacts their longevity. If you tend to blast your speakers at a high volume, you are more likely to damage the capacitors in the crossover circuit or the amplifier in an active speaker.
Along with damaging the capacitors, listening to music at high sound levels for a long time may also damage the speaker cone. A blown speaker may sound distorted or produce no sound at all. It may start as a small tear in the cone and gradually worsen.
You may also blow the speakers by damaging the voice coil inside the driver. This is typically caused by mismatched impedance levels between the speakers and the amplifier. For example, using 4 Ohms speakers with an 8 Ohms amp may cause you to increase the volume. The increased power produces excess heat that may damage the coil. It can also cause the cone to vibrate violently, causing a tear.
Most speakers include MDF enclosures with vinyl wraps. The wraps are prone to chips and scratches even when buying from some of the top brands. Use caution when transporting or storing your speakers to protect the exterior.
Maintenance
Maintenance is also essential for increasing the life of your speakers. Keep your speakers and audio equipment free of dust, especially near the vents and openings. Dust accumulation may block the flow of air, keeping heat from escaping. Too much heat may damage the coils, blowing the speakers.
You may also need to occasionally wipe the dust cover (grille) on the front of the speakers with a slightly damp lint-free cloth to remove dust and hairs that get caught. As with the capacitors, the dust cover is typically replaceable.
Proper placement may reduce the accumulation of dust on the speakers and the grille. Do not place the speakers in tight spaces that may block the flow of air, such as a small shelf on a bookcase. The speakers should also be placed away from other components to reduce static electricity and interference.
Avoid letting your speakers sit unused for prolonged periods. Capacitors deteriorate faster when they remain unused for extended amounts of time. At least every few months, you should play audio through the speakers to help the capacitors maintain their capacity.