SM57 vs SM58
Question: What are the real reasons an SM58 should be used for vocals, and an SM57 be used for instruments? Of course, everybody seems to use these mics as mentioned. No one has given me a convincing reason for this, other than 'That's just what you do- everyone does it this way'. Please ease my anxious mind!
Answer: It is true the SM57 and SM58 microphones are based on the same cartridge design. The main difference between them is in the grille design. The SM58 was designed for vocal application and it uses a separate grille with a very effective pop filter. The SM57 was designed as an instrument microphone where smaller grille size is preferred. In this application the pop and wind are not usually a concern. The SM57 uses an integral resonator/grille assembly, where grille is actually a part of the cartridge. These two grille designs place the diaphragm of the microphones in a different acoustical environment. First of all, the distance from the top of the grille to the diaphragm is significantly shorter on the SM57 compared to that of the SM58. This allows for closer sound pickup with even more pronounced proximity effect. Secondly, a different resonator/grille assembly design of the SM57 is responsible for its slightly higher output above 5 kHz.
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Question:
---- 09/23/2001 09:37 AM ---------------------------------------------
Hi Why does the 57 sound so much different than the 58? I know the grill affects the sound and so does porting and microphone body shape and size. The specs say the 57 goes a bit lower yet many people feel the 58 is bassier sounding. I'm guessing their perception of bass is actually lower mids but I can't find any frequency graphs on your site to confirm this. I would have expected the 57 to sound bassier because a greater proximity effect is possible since you can get closer to the cartridge but I guess many people's sense of bass is not really low frequency extension.
---- 09/23/2001 09:49 AM ----------------------------------------------
the graphs I viewed in PDF format doen't seem to correspond with what I hear. Do these mics have different proximty effect characteristics?
Answer: The SM58 and the SM57 share the same mic element, the Unidyne III. The only difference between the these two models is the grill design.
The grill design does affect the high frequency response, particularly above 8,000 Hz.
The SM57 grill design allows more proximity effect because the mic diaphragm can be placed closer to the sound source. Proximity effect increases each time the distance from the mic to the source is halved. When a mic is placed very close, it is quite easy to halve the distance: 1 inch to 1/2 inch; 1/2 inch to 1/4 inch; etc. Remove the ball grill from the SM58 and it will be more similar to the SM57 in its low frequency response.
Any other differences you hear between the SM57 and SM58 are likely to be subjective (psycho-acoustic) or due to slight manufacturing differences due to part tolerance.
Question: Do the SM58 and SM57 mics have the same frequency response curves? Is a 58 simply a 57 with an integral pop filter/windscreen?
Answer: The SM58 and SM57 do use the same cartridge. The grill, though, does effect the frequency response to some extent. At a distance, the difference is probably not noticable. But at extremely close distances, the difference is noticeable. Due to the grill, a person's mouth can get closer to the diaphragm of an SM57, thus causing more proximity effect and increased bass when compared to the SM58.
Note that the cartridges are not interchangable because the mounting scheme is different for the two microphones.
