MicTested
SM57 vs SM58: Same Price, Different Cartridge
MicTested
Buy the SM58 for a voice and the SM57 for anything else, and the reason is one published number rather than a preference. Both cost $109. Both put out −56.0 dBV/Pa. Both stop at 15 kHz. The SM58 publishes how much it rejects from the sides and behind, while the SM57 publishes a curve and no figures. On a stage with a monitor pointed at the grille, no other row of the two sheets matters as much.
For an instrument the argument reverses. The SM57 reaches 40 Hz where the SM58 starts at 50, and its flat grille puts the capsule closer to a drum head or a speaker cone than a ball grille allows.
What actually differs
| SM57 | SM58 | |
|---|---|---|
| Price | $109.00 | $109.00 |
| Sensitivity | −56.0 dBV/Pa (1.59 mV/Pa) | −56.0 dBV/Pa (1.59 mV/Pa) |
| Frequency response | 40 Hz to 15 kHz | 50 Hz to 15 kHz |
| Off-axis attenuation | not published | 2 dB at 60°, 10 dB at 120°, 20 dB at 180° |
| Output impedance | 310 Ω | 300 Ω |
| Weight | 284 g | 327 g |
| Grille | Flat, polycarbonate with a steel screen | Spherical steel mesh |
| Cartridge part | R57 | R59 |
| Grille part | RK244G | RK143G |
| Owner rating | 4.9 from 131 | 4.9 from 165 |
Five rows carry a difference worth acting on. Those are the low end, the rejection figures, the grille shape, the mass and the part numbers. And the rest is the same microphone twice.
No, they are not the same capsule
The common claim is that the two are one microphone in two grilles. But Shure's own parts lists say otherwise. The SM57 guide names its replacement cartridge as the R57, shared with the SM56. The SM58 guide names the R59. Two part numbers, two cartridges, and Shure sells them separately.
What the folklore gets right is that the two are close relatives with the same published sensitivity, though the difference on paper is small. What it gets wrong is the mechanism. The 10 Hz at the bottom and the shape of the response aren't the grille alone.
The grilles differ too, and by their own part numbers: RK244G on the SM57, shared with the 545SD, and RK143G on the SM58. And neither fits the other.
The rejection figures, which only one of them publishes
| Angle | SM58 attenuation |
|---|---|
| 60° | 2 dB |
| 120° | 10 dB |
| 180° | 20 dB |
Twenty decibels at the rear means a sound source behind the microphone arrives about a tenth as loud in pressure as the same source in front. That's the number that decides whether a wedge monitor aimed at a singer starts feeding back. Eleven microphones out of the 82 collected here publish these angles at all, and the SM58 is one of the eleven. The SM57 isn't. Both are cardioid and both reject from behind, but only one says by how much, and a figure nobody prints can't be compared.
But this isn't evidence that the SM57 rejects less. It's evidence that a buyer choosing for a live vocal has a number for one and nothing for the other.
10 Hz at the bottom, and what it is worth
The SM57 publishes 40 Hz, the SM58 50 Hz, and neither states a measurement level, so the gap can't be checked against another maker's numbers. Inside the catalogue of a single maker it still means something. Shure chose to print a lower figure for the instrument model.
Ten hertz at that end of the range is roughly the difference between the lowest note of a five-string bass and the lowest note of a four-string. On a kick drum, a floor tom or a bass cabinet, that region carries weight a vocal never reaches. On a voice it carries mostly stage rumble, and that's why the vocal model gives it up.
The grille is a working difference, not a style one
A ball grille holds a singer's lips about two centimetres off the diaphragm. But a flat grille lets the capsule sit against a drum head, inside a kick, or a few millimetres from a guitar cone. A third shape skips the stand altogether: a Sennheiser e604 clamps to the rim at 60 g. That geometry is the reason engineers own both, but it's not a preference. The distance a grille enforces changes the proximity build-up and the maximum level reaching the capsule.
And the mass follows the shape. At 284 g the SM57 is 43 g lighter, which matters on a boom arm hung over a drum kit though not at all in a hand.
Same price, so the choice is not about money
$109 each, which makes this the rare comparison where cost drops out completely. Neither carries a pad, a filter or a switch. There's no maximum SPL from either. Neither needs power.
Because it undercuts both by half and puts out 2.5 dB more, the $54 PGA48 is worth naming here. The trade is its low end, which starts at 70 Hz, and Shure prints no rejection figures for it either.
Common questions
Are the SM57 and SM58 the same microphone?
No. They share a published sensitivity of −56.0 dBV/Pa and a 15 kHz top end, but Shure lists different cartridges, R57 against R59, along with different grilles and different low limits.
Can the SM57 be used for vocals?
Yes, and it often is. What it lacks is the published rejection figures and the ball grille that sets a working distance. What it adds is 10 Hz at the bottom that a voice doesn't use.
Can the SM58 be used on instruments?
Yes, with one caveat. The ball grille keeps the capsule further from the source, which changes the level and the proximity build-up on a close-miked drum or cabinet.
Which is louder?
Neither. Both publish −56.0 dBV/Pa at 1 kHz, which converts to 1.59 mV/Pa, and both sit sixth and seventh from the bottom of the seventeen dynamics here that publish a comparable figure.
Which one to buy
A voice into a PA with monitors on stage means the SM58. The rejection figures are published, the ball grille sets the distance, and 50 Hz is deep enough for a voice.
A snare, a guitar cabinet, a tom or a horn means the SM57. It reaches 10 Hz lower, sits 43 g lighter on an arm, and its flat grille goes where a ball can't.
Both, if the work is mixed. At $109 each, with the same output and the same top end, owning one of each covers stage vocals and instruments without a compromise in either direction. And that's why so many racks contain both. Neither choice is a mistake the other one fixes, though, because the cartridge and the grille are answering different questions about where the microphone will stand.
Sources
- Shure SM57-LC and SM58-LC product listings at B&H Photo Video: prices, rating counts and star distributions.
- The product markup on those listings: frequency ranges, sensitivity, dimensions, weights, mounting threads, and the off-axis attenuation figures published for the SM58.
- SM57 user guide at Shure: output impedance, housing materials and the R57 cartridge and RK244G grille part numbers.
- SM58 user guide at Shure: output impedance, the spherical steel mesh housing, and the R59 cartridge and RK143G grille part numbers.
- Medians, positions and the count of microphones publishing off-axis figures come from listings of 200 audio products collected the same way. How those are converted and compared.
What the counter showed on 20 August 2026 is what the prices above say.
What we did not doNeither microphone has been in our hands. Every figure above is Shure's or its dealer's; what we add is the side-by-side and the part numbers that settle whether the capsules are the same.
