Listed above are the three most common magnet types used in speakers today. Ferrite magnets, also called ceramic magnets, are low cost magnets that maintain their magnetic strength well. They are heavy and are not generally used for applications that require portability. Speakers that incorporate ferrite magnets will tend to sound better when driven near the maximum handling capacity. AlNiCo magnets were the first magnets used in speakers and are what helped give them a smooth tone. Speakers that incorporate AlNiCo magnets are a more expensive option than ferrite-based speakers, but they are less prone to cracking. Neodymium magnets offer the highest field strength of any permanent magnet known. Speakers made with NdFeB magnets offer a good frequency response, are light in weight and are much smaller than speakers that incorporate ferrite or AlNiCo magnets. This makes them an ideal magnet for small speakers that are required to output a high SPL.