Shure KSM27 Cardioid Condenser Microphone

By • Nov 15th, 2007 • Category: Articles, Audio Gear, Audio Reviews

by Stephen Murphy

Shure made an impressive entry into high-end recording with the introduction of the KSM32 cardioid and KSM44 multipattern condenser mics.

The latest arrival in the Shure KSM family, joining the aforementioned KSM44 ($1,393, see PAR 01/01) and the KSM32 ($1,070, see PAR 01/99) is the low cost KSM27 ($575) fixed-pattern cardioid condenser mic.


At nearly half the cost of its nearest family member, the KSM32, the KSM27 presents an intriguing quandary to potential purchasers. They both are cardioid-only, and share many of the same premium features: 24 karat gold-layered, low-mass Mylar diaphragm; Class A, discrete transformerless preamplifier; gold-plated internal and external connectors; internal subsonic filter (17 Hz); switchable -15 dB pad; three-position low frequency rolloff (flat; -6 db/octave below 115 Hz; -18 dB/octave below 80 Hz); construction includes an internal three-stage pop protection grille and shock insulated electronics.

Shure KSM27

Both the KSM27 and the KSM32 boast low self noise (14 dB and 13 dB respectively), high SPL handling (138 dB and 139 dB with a 2500 ohm load, 15 dB higher with pad), similar sensitivity (-37 dBV/Pa and -36 dBV/Pa at 1000 Hz with 1 Pa = 94 dB SPL) and the same signal-to-noise ratio (81 dB).

Beyond the above features and specifications, the two mics are actually quite different in circuit design and construction. The externally biased KSM27, built to withstand both studio and live use, weighs in at a hefty 22.6 ounces, compared to the permanently-biased KSM32’s 17.3 ounces. The 6.15-inch long KSM27 – over an inch shorter than the KSM32 – has a stocky, rugged feel that instills confidence for use outside of the padded studio world.

Part of the savings realized in the KSM27’s low price comes from the more basic presentation and accessories. The KSM32 and 44 studio models each come equipped with a super-cool locking aluminum carrying case, a full-sized elastic-suspension shockmount, a standard swivel mount and a regal velveteen pouch, while the KSM27 kit simply includes a smaller, low-profile (but equally effective) rubber-isolated shockmount and the velveteen pouch. This is a good kind of trade-off for people looking to save some dough – the kind that does not affect sound quality.

Studio, broadcast, location recording, live sound

Key Features:
Cardioid condenser mic with 1-inch Mylar diaphragm; Class A, discrete transformerless preamplifier; gold-plated internal and external connectors; internal subsonic filter (17 Hz); switchable -15 dB pad; three-position low frequency rolloff (flat; -6 db/octave below 115 Hz; -18 dB/octave below 80 Hz).

$575 (MSRP)

Studio – API 212L mic preamps, UREI 1176 compressor, Zaolla Silverline mic cable, Pro Tools recorder, Westlake Lc8.1 monitors, Hafler P3000 amplifier.
Live recording – Mackie 1604 VLZ-Pro mixer, PreSonus ACP88 compressor, Panasonic 3800 DAT recorder.

In use

So how does it sound? Not so fast, eager readers. Because of the KSM27’s and 32’s many apparent similarities, and one glaring disparity (price), it is important to understand the intended applications for which they were designed.

In the KSM32, Shure succeeded brilliantly in producing an open, natural-sounding mic with a near-flat frequency response, perfect for capturing a close reproduction of the original sound source; an excellent “open-palette” studio mic, easily comparable to mics costing more than twice as much.

With the KSM27, Shure narrowed the playing field (and cost) by producing a mic with a specific application in mind: vocal recording. The KSM27 has a gentle low frequency boost (which increases greatly with proximity) and a hyped top end (a broad curve starting at about 2.5 kHz, rising to almost +5 dB at 6.5 kHz, and eventually making its way back down to +0 dB by 18 kHz). In other words, the “smile” curve.

Shure simultaneously broadened the potential market for its new mic by making the KSM27 rugged enough for live use. That is not to say that the KSM27 won’t work on other instruments, or that it is not good enough for the high-end studio; just that the KSM27 is clearly designed to be a workhorse vocal mic, and that is where it shines, as I found out.

For this review, I received a pair of KSM27s. I proceeded to put them to use in a variety of applications including recording layered backing vocals, lead vocals, acoustic and electric guitar, assorted hand percussion, drum overheads and grand piano.

On the piano and guitars, I got good results, but not good enough to stop me from swapping the KSM27s out for the KSM44s on the actual recordings; too much top and bottom emphasis for predominately middle-range instruments.

The mics proved their worth and then some on drum overheads. With the 115 Hz rolloffs engaged, the KSM27s added the desired high end “shimmer” to the cymbals with little drum “boxiness” in the low mids. The hand percussion recordings also went well (tambourine, egg shaker, triangle); plenty of top end to cut through the mix without additional EQ.

As expected, the KSM27 made a strong showing on just about every vocal I recorded. With the exception of an excessively sibilant female, all the vocal tracks I recorded had a comfortable amount of “air” and low-end warmth. The proximity effect was easily manipulated to provide the “up close and personal” sound, perfect for voice over and broadcast use.

I turned the pair of KSM27s over to recording engineer Andrija Tokic, charged with recording a live event called “Drums Along the Potomac.” The recording consisted of five hours of regional drum corps performances. For the uninitiated, drum corps are typically made up of five to ten marching bass drums, ten to twenty snare drums and an army of fife and/or brass players.

Andrija set up the KSM27s 12 feet apart, 12 feet off the ground and, depending upon the corps, 8 to 12 feet from the front line performers.

The resulting recording, when brought to my studio for editing and mastering, surprised and impressed us both. The tight cardioid response did an excellent job of rejecting major reflections from the rear of the big performance hall, leaving a nice balance of direct sound and close ambience, with just enough hall ambience. The stereo imaging was wide, yet still possessed a cohesive center. Tonally speaking, very little EQ was needed in the mastering process.


My evaluation of KSM27 revealed its strength as a workhorse vocal mic. It is built to withstand constant use in a variety of environments and, when applied to appropriate sources, the mic yields a very good recording. Shure has managed admirably to produce a value-priced vocal mic worthy of the KSM lineage.


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