Shure Beta 58A (dates not documented)

A supercardioid workhorse that follows the SM58's footsteps and then sharpens the attack.

Overview

The Shure Beta 58A weighs 278 grams, and that heft turns out to be a handy authentication check - more on that later. It is a high-output supercardioid dynamic vocal microphone, built for professional sound reinforcement and project studio recording. It follows directly after Shure's own SM58, the mic that has been the industry's default vocal tool for decades. The Beta 58A is not a replacement for that mic. It is the version Shure aimed at engineers who wanted a tighter pattern and a brighter top end.

The difference shows up most on a loud stage. The Beta 58A keeps a true supercardioid pattern across its frequency range, which gives high gain before feedback and better isolation from the rest of the band than a cardioid pattern can manage. Sources call the pattern supercardioid consistently - Thomann's listings, Kytary.ie, and Shure's own product copy all agree. At least one reseller listing says "Cardioid," which looks like a catalog error rather than a design variant. The mic needs no power source, which is standard for a dynamic and one reason it survives bar gigs, outdoor festivals, and whatever else gets thrown at a working vocal mic.

Shure's own materials describe the Beta 58A as offering "exceptional intelligibility and transparency across the spectrum." The frequency response is shaped for close-up work: 50 Hz to 16 kHz with a gentle boost above 3 kHz. That upper-mid lift gives the mic its presence and makes a vocal sit forward in a mix without much EQ. It is not a flat, neutral microphone, and it was never meant to be.

Key Features

True Supercardioid Pattern Throughout the Range

The polar pattern is the main thing here. Shure specifies a true supercardioid response across the microphone's entire frequency range. Not every supercardioid mic can claim that - many narrow their pattern only in the midrange and widen at the extremes. In practice the Beta 58A rejects more off-axis sound than a cardioid mic at the same distance. That means higher gain before feedback and less bleed from monitors, drums, or the guitarist's amp.

The trade-off is that supercardioid mics pick up more from directly behind the capsule than cardioid designs do. That catches some users off guard. It is not a flaw, but it is worth knowing before you point the back of the mic at a wedge monitor.

Shaped Frequency Response for Close-Up Vocals

The 50 Hz to 16 kHz response is not flat. It is shaped, with a gentle boost above 3 kHz that flatters the human voice. That lift adds intelligibility and presence, and helps a vocal cut through a dense stage mix without aggressive EQ.

Compared to the SM58, the Beta 58A has less output in the low mids - roughly 250 to 800 Hz - according to Mix (July 1996, p.174). The same review noted that the earlier Beta sat about 2 dB below the SM58 at 8 kHz, a deficit the updated model traded for a couple of dB more at 6 kHz. The result sounds related to the SM58 but noticeably brighter and more present, while the SM58 stays the warmer, more forgiving option.

Neodymium Magnet and Hardened Steel Grille

Shure builds the Beta 58A around a neodymium magnet, which contributes to the mic's high output and helps keep the body compact. The grille is hardened steel mesh, made to take the abuse touring microphones get - drops, stand knocks, and the occasional collision with a cymbal stand.

No Power Required

The Beta 58A is a dynamic microphone and needs no power source. There is no phantom power to worry about, no battery to die mid-set, and no active circuitry to fail. That simplicity is a large part of why the mic has stayed in production and on riders for so long.

Accessories and Physical Details

Shure ships the Beta 58A with a microphone clamp, a 3/8" threaded adapter, and a bag. The mic measures 160 mm long with a 50 mm diameter body and weighs 278 grams. Output impedance is listed at 290 ohms, and open-circuit voltage at -51.5 dBV/Pa (2.66 mV). A windshield is available separately (Art. 135783) but is not included.

Historical Context

The Beta series originally launched in 1989, and by the mid-1990s Shure had updated and augmented the range. Sound on Sound (1996, p.38) noted the refresh, and Mix (1996, p.160) reported on Shure's expansion and improvement of the Beta family at that year's NAMM show. The new Beta 58A carried a list price of $266 at the time, while the Beta 87 remained unchanged at $434.

The revision was not cosmetic. Mix (July 1996, p.174) reviewed the Beta 57A and 58A together and found that the updated 58A had less low-mid output than the SM58 and a revised high-frequency balance compared to the earlier Beta. That was a deliberate retuning rather than a badge refresh. The Beta 58A has stayed in the catalog while many other microphones from the same period have come and gone.

Mix (February 2008, p.79) documented a touring rig where the engineer moved from a Shure Beta 58A to an Audio-Technica AE6100 for main vocals but kept the Beta 58A on backup vocal duty. A 2013 Mix rebate promotion (April 2013, p.7) listed the Beta 58A among the vocal models in the Beta range, so the mic was still part of Shure's lineup more than fifteen years after its introduction.

Collectibility & Value

The Beta 58A is not a collector's microphone the way a vintage ribbon or a rare condenser might be. It is a working tool that Shure has continued to produce in large numbers. The used market is still active, and prices vary widely depending on condition and provenance. One Craigslist listing cited a new price of $169, though that figure is undated and may not reflect current retail. Used examples show up regularly, often described as being in "good pre-owned condition" with "minor wear and tear typical of normal use."

Counterfeits are a real concern. A genuine Beta 58A weighs 278 grams, and at least one seller has used that figure as a verification standard. The weight difference between a genuine mic and a counterfeit is often noticeable in the hand, even if the outside looks convincing.

Shure has refurbished units in circulation. One Craigslist listing described a mic as "completely refurbished by Shure and never used since." Third-party replacement head capsules are also available on the secondary market, compatible with the BETA58/58A, so a damaged grille or capsule does not necessarily end the microphone's life. No common failure modes or repair procedures are documented in the available research.