McGary Audio

Tuesday, August 4, 2009

Home Recording On A Budget:
Shure SM-27 Condenser Microphone

by John Gatski

Shure has been producing high-quality, USA-manufactured microphones for more than 60 years — offering up the ubiquitous SM-58 and SM-57 dynamics, as well as its high-end KSM-32, full-size condenser and excellent KSM-137/141 instrument mics.
To play in today’s hyper-competitive microphone market, many U.S. manufacturers have gone offshore to make cost-effective, good-performance microphones, produced mainly in China. But Shure has produced an assembled-in-USA mic that competes with the Chinese-made mics in price, but offers quite good quality sound and features. The Shure SM-27 is a nice match for home or professional recording tasks.

The SM-27, priced at $460 MSRP and $299 on the street, is a full-sized condenser microphone. It looks similar to the high-end Shure KSM-32/KSM-44 microphones. It features an externally biased, condenser element with a 1-inch mylar diaphragm. Its cardioid polar pattern and side-address design allow for direct recording of sources, such as voice, acoustic/electric guitar, drums, brass, violin and piano. The larger diaphragm also makes the microphone better suited for voice or instruments.
Like all condensers, the microphone requires 48 volts of phantom power from a standalone microphone preamp or a mixer preamp. With a preamp-to-A/D converter interface, it also can be used for laptop recording.
To make it more versatile for live sound or louder recording applications, the microphone includes a 0 dB/-15 dB pad switch to accommodate different preamp gains and a - 6 dB/-18 dB low-cut filter to reduce enhanced bass proximity effect when close-miking instruments, such as drums or acoustic guitar.

Spec-wise, Shure rates the microphone at 20 Hz to 20 kHz response. There is no stated tolerance, but the mic’s factory-supplied measurement response plot is mostly flat to 3 kHz; there is a gradual rise of about 4.5 dB to 7 kHz, a 2 dB decline at 8 kHz and a 1 dB rise to 15 kHz. The response falls off at 15 kHz-20 kHz by about 3 dB. Overall, the response is typical of good-performing condensers I have sampled in this price range.

The self noise is an excellent at 9.5 dB, and rated maximum SPL is 133 dB before attenuation. No problem with loud guitar cabinets for this mic. The microphones comes with a carrying pouch, and a screw-on collar mount that will fit any mic stand. For vocal use, you might want to buy the optional suspension mount and foam screen.
As founding editor of Pro Audio Review for more than 13 years, I have sampled scores of microphones, expensive and budget. The SM-27 is a testament to the kind of quality you can get from a low-cost mic these days. This microphone is ruggedly built; the switches worked perfectly — and the finish application is consistent.

The set up
Although the SM-27 can be used with almost any instrument, I used it in my familiar setup of acoustic guitar, electric guitar/amplifier, and vocal. My test setup included the excellent-sounding API A2DA microphone preamp/analog-to-digital converter combo (up to 192 kHz), Accusound microphone cables, and TASCAM DVRA-1000 DVD+R high-resolution stereo recorder. I also recorded onto a Apple Macbook Pro laptop via Benchmark Media MPA-1 mic preamp and Benchmark ADC1 converter.
All tracks were played back via either the TASCAM or the Macbook Pro, each connected to the Benchmark Media DAC1 Pre driving a pair of AKG 701 headphones. All components were connected to the AC via Essential Sound Products premium AC cords.
After mounting the mic on an Atlas mic stand, I recorded three acoustic guitars — a Martin Custom Shop OO-28, a production-line Martin OO-18V and a Gibson SJ200 — and Gibson L5CES electric hollowbody jazz guitar with Fender Twin Reverb Reissue amp. Vocals were done by me with mostly spoken word recordings and then comparing the same recordings made on other mics.
I mounted the mic on an Atlas mic stand and connected it to the preamp. Since I only had one SM-27, I could not do a true stereo recording, which I love to do with acoustic guitar. But I selected the dual-mono option on the recorder and was able to make a variety of recordings and get a sense of the microphone’s sound.

The audition
First up was my recently acquired Martin 00-18V, a small-size, solid-mahogany/Sitka spruce top with 24.9-inch scale length. This is an excellent fingerpicking guitar with complex harmonics and a midrange emphasis that is only flattered when recording with a good microphone. I played around with the distance and finally settled on 10-inches from the guitar — aligned with the sound hole. I set the API converter/preamp for 24-bit/96 kHz audio, and made several recordings.
The recording playback was impressive. This sub- $350 retail microphone showcased the Martin quite well. The midrange and low-treble treble rise characteristics of the mic never overemphasized the the Martin. There was a bit of boost in those frequencies, but in a pleasing way. I really liked it.

I then switched off to the rosewood body guitar — the Martin Custom 0028. It has a mellower upper-mid and low-treble projection than the mahogany-body 0018V. Again, this low-cost Shure really showcased the darker flavor of the small fingerpicker guitar, but yet relayed a slight warm presence of the top end that sounded nice when played back through the editing laptop and Benchmark DAC1 Pre.
I got more daring and pulled out a Gibson Super Jumbo SJ200, a solid-maple body with spruce top, to see how the SM-27 handles a big booming guitar with a flatpick. I initially set it up with no roll-off, but with the 10-12-inch mic placement the bass was a bit overly boomy with this big guitar. So I engaged the -6 dB low-cut filter, and no more boom. The cool, crisp, pronounced big sound of the Gibson was tracked just right. For a low-cost mic; the Shure SM-27 does a big guitar proud.
With the Gibson L5 CES jazz guitar and Fender Twin Reverb, the mic captured most of the essence of the humbucker pickup and hollowbody’s warm, expressive, sonic colors. It did not quite capture the ultra presence like some of my more expensive mics with 24/96 recording — such as the Shure KSM-32, a DPA condenser, Audix SCX-25, or my Lawson Tube L251 big tube condenser — but I was satisfied with the quality at such a good price. To do the guitars full justice, however, ya gotta mic in stereo. Therefore, when you plunk down your credit card, buy two!
My voice sounded pretty good. — a little midrange emphasis, but not overly pronounced or sibilant. I did not try the SM-27 on drum overheads, violin, piano or brass, but the smoothness of guitar recordings showed me that its is not an overly mid- peaked or treble-peaked mic that could impart recorded harshness. As a budget mic, I think it will be fine for those instruments.

The verdict
Despite the lower price, the Shure SM-27 is a good-performing, full-size microphone that offers the desired tonal characteristics you want from a condenser; it is quite worthy of the Shure moniker. Couple the solid performance with a decent mount and a carrying pouch at $300 bucks street, the SM-27 is recommended for the basic computer recording crowd, all the way up to the seasoned pro who needs an extra mic in the studio.
For more information on the SM-27, visit

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