Ever since the Shure SM7 was originally released in 1973 it has been a mainstay in studios – and even on stages – around the world. The SM7 was conceived, first and foremost, as a dynamic broadcast microphone for use in TV and Radio studios. Shure gave its R&D team virtually carte blanche to come up with the ”ultimate broadcast mic”, based on the design principles of the company’s Unidyne III capsule.
A slightly larger diaphragm and the different body design – when compared to a typical handheld mic, like an SM57 or SM58 – made it possible to come up with a cardioid dynamic mic that offered an unusually linear frequency range. Placing the capsule about halfway between the tip of the microphone and the body also cut down on unwanted boominess, often caused by the proximity effect present in unidirectional mics. An internal humbucking coil efficiently eliminates noise pickup via electromagnetic interference from transformers, dimmers, wireless equipment, and the like.
Since its original release in 1973 the Shure SM7 has gone through a couple of minor improvements; the current version is called the Shure SM7B (current street price in Finland around 365 €).
This is what you will find in the cardboard box:
- The Shure SM7B itself with its regular, smaller windshield attached
- A second, larger windshield for windier outdoor applications, or for close-miking vocal performances
- A screw-in thread adapter from the larger US-standard thread to the narrower European standard for microphone stands
- A cover plate to make accidental changes to the EQ-switches at the back impossible
The two EQ-switches on the back give you an optional bass cut and a presence boost. Engaging both switches will tailor the SM7B’s frequency response to something more similar to a ”regular” cardioid dynamic mic, like the SM57 or SM58.
Depending on whether you want to use the SM7B hanging from a boom arm or placed on a regular mic stand, you may want to change the mic’s orientation inside the yoke to have the legend on the back facing the right way up. The owner’s manual takes you through the correct procedure to unscrew the SM7B from – and reattach the mic back to – the yoke.
A good way of conducting a listening test to find out a microphone’s frequency response is to make a recording of pink noise.
Pink noise is a type of artificially generated hiss that includes the whole audible frequency spectrum. In contrast to white noise however, which features each frequency at the same dB level, pink noise is ”corrected” to have all the frequencies sound equally loud to the human ear. This is achieved by decreasing each higher octave by one to three dB in relation to the previous octave. To the human ear white noise sounds harsh and thin, while pink noise provides a much more balanced spectrum of noise, making it easier to notice differences in the all-important mid-range response of microphones.
My first comparison was between the Shure SM7B and an SM57:
The difference in sound is very obvious:
With the capsules/diaphragms of both mics being equidistant to the sound source (a Genelec 8030A nearfield monitor), the SM7B sounds much smoother compared to the strong presence lift and the discernible bass roll-off displayed by the SM57.
Next I used the same setup to compare the SM7B to the recent ”podcast model”, the Shure MV7X:
To my ears the Shure MV7X sounds like a compromise between the company’s legendary stage mics – the SM57 and SM58 – and the broadcast-cum-studio legend that is the SM7B. The MV7X comes close to the bottom-end warmth of the Shure SM7B, while at the same time offering more of a presence lift than the SM7B’s EQ-switch.
One thing the Shure SM7B is not is very sensitive (read: loud).
Internet forums are filled with threads discussing the compatibility of the Shure SM7B with regular computer audio interfaces. Many claim that the mic preamps in most audio interfaces may not offer enough gain to amplify the SM7B to an adequate recording level. Musical equipment retailers have also latched on to this idea, with many offering the mic in bundles with small phantom-powered JFET-amps that bump up the Shure SM7B’s output level by 20 or 30 dB. Products often mentioned in this context are the Cloud Cloudlifter, the Triton FetHead or the Thomann FetAmp to name only a few.
I decided to test how my Focusrite Saffire 6 USB got to grips with the SM7B’s output level, by first recording a bit of acoustic guitar strumming using the interface’s own mic preamp, after which I recorded the same passage using Thomann’s FetAmp between the Shure and the Focusrite.
I found that I really had to add a lot of gain on the Focusrite’s mic preamp (around 90% of the available gain) to get a healthy recording level out of the SM7B without the additional in-line amplifier. Despite the hefty gain level the recording sounded very good and wasn’t hissy or distorted in any way.
Inserting the Thomann FetAmp in the signal chain did make it much easier to get a good recording level out of the Shure SM7B. I only had to add approximately 25 to 30 percent of the Focusrite’s own mic preamp’s gain reserves. In terms of sound I could hardly make out any difference between using only the audio interface and adding the in-line amplifier.
To sum things up, I’d say that a decent audio interface should offer enough gain to work smoothly with the Shure SM7B. On the other hand, the signal boost that one of the relatively affordable in-line amps will bring to the table will make recording the SM7B noticeably easier.
As our main focus here at Kitarablogi.com lies in making music with string instruments, I wanted to find out how the Shure SM7B works as a mic in the home/project studio. For this purpose I recorded two demo songs.
Here’s the acoustic song:
In addition to samples of a bass drum, a hi-hat and a floor tom, I used a wide variety of different acoustic sound sources:
- a metal shaker
- a wooden shaker
- a tambourine
- a double bass
- two tracks of acoustic guitar
- a Weissenborn-type lap steel
- an accordion
- a harmonica
- and several tracks of vocals
The SM7B worked great with any sound source I could throw at it. Nothing ever sounds harsh or thin through this mic, and it was easy to use the DAW’s own EQ to tailor each sound to my taste. The fatter windshield supplied with the Shure, called the A7WS, makes it possible to close mike a blues harp and vocals without any trouble caused by breath noises or plosives.
For the second demo song I chose an environment with electric guitars and amps:
This song contains the following tracks recorded with the Shure SM7B:
- a Squier Bronco Bass played through a Bluetone Bass 200 tube hybrid combo
- two Fender Stratocaster rhythm guitar tracks (stereo left and right) with an EHX Nano Small Stone phaser through a Bluetone Black Prince Reverb all-valve combo
- a Fender Telecaster rhythm guitar track (centre) through a Bluetone Black Prince Reverb combo
- a Fender Telecaster lead guitar track with a Mad Professor Simble Overdrive through a Bluetone Black Prince Reverb combo
- a metal shaker
- a tambourine
- a little bit of vocals
Again, I had no trouble whatsoever recording the different instruments, and the mixing proved unproblematic, too. The Shure SM7B sounds very neutral – in the most positive sense – and doesn’t push the sound into any predetermined direction. This means it never works against you, but rather leaves everything wide open for you to make your own mixing decisions.
Judging from my time with the Shure SM7B I can only say that this mic’s legendary status is not down to hype of any sort, but rather a result of its set of features. The SM7B is no cheap microphone, for a dynamic mic, but it rewards its user with an excellent, almost linear frequency range, great hum rejection, a tolerance for high sound pressures, and very even directivity.
The SM7B works excellently with virtually any sound source you can throw at it. Yes, it was once designed to be a radio and TV mic, but this Shure microphone can handle far more than merely close miked speech.