For years the SM58 was the industry standard for live performance. Anyone and everyone used them. Used live and even used in the studio (SM stands for studio Mic).
It is rugged, reliable, and with its thick capsule and cardioid polar pattern, it helped isolate the main sound source and minimize background noise and feedback. With a frequency response of 50 Hz to 15,000 Hz it was quite impressive back in 1966 when it was first introduced. Even today with a $99.00 price tag is still a popular choice.
However, the old 58 has a dip in the upper midrange frequency, a quick drop off in the response around 13,000 K, and because of the cardioid polar pattern an issue with proximity effect. When you accentuate lower frequencies you muddy them up and it also effects the midrange and masks some of the hi frequency response removing the air that is associated with clarity, space and, sibilance.
However, as the saying goes out with old and in with the new.
Telefunken Elektroakustik created the M80 to give the user a superior alternative to the midrange-laden characteristic of the old 58. With a wider frequency response and higher SPL capabilities, it delivers a condenser like performance. Due to its low mass capsule and thin capsule membrane the M80 presents a wider range of emotion from live vocals and even in the studio.
The head grill and capsule assembly has been designed to reduce proximity effect resulting in added low-end clarity without messing with the mid or hi end frequency providing strength and authority with an open airy character.
The M80 also offers a custom wound impedance matching transformer when coupled with the proprietary capsule assemble gives this mic a clear pure sound unmatched by any competitor today.
The cost although a little higher than the SM58, is still very affordable and the improved performance far exceeds the difference in the price point. If you do not know someone who uses a M80, you soon will.