Shure is one of those manufacturers every engineer and musician knows. Its hugely popular SM58 has been the star microphone of live shows for decades. How strange it feels to see a concert with a singer who isn't using a 58! Far from being the result of a carefully crafted "marketing" strategy, the SM58 has earned that trust through its performance and quality. A resounding success. But can this model be improved?
Another of the brand's milestones was (and still is) the Beta series. Under this banner, the manufacturer proposed a series of improvements to many of its star microphones, which brings us to our two guests in these pages: the Beta 58A (with the particularity that it is wireless) and the Beta 87A, the latter a condenser. Both models, in their non-Beta versions, have been a benchmark for many engineers and musicians; let's see how they perform in their "improved" versions.
Beta, the noticeable upgrade
Why did Shure come up with the Beta series? Presumably the brand "listened" to its customers and turned their (always constructive) opinions and criticisms into a new series. For example, a Beta 58 differs in a great many ways from a, let's say, conventional SM58. First, and most obviously, the Beta58 has a supercardioid design, while the SM58 is cardioid. This request would give tighter control over feedback from monitors, although it reduces dynamic response at off-axis angles (which can be a problem with singers who are not very experienced at handling a handheld mic). In output level, the Beta 58 is 4 dB higher, so it achieves a better dynamic level at FOH, or, to put it another way, it needs less preamp gain, which means less added noise. Speaking of noise, according to the manufacturer a Beta 58 has "less" handling noise than a 58, and its protective grille is even much sturdier. There is also a noticeable difference in frequency response, which is more extended in the low and high frequencies. Does that mean the Beta 58 is better than the SM58?
As for the Beta 87A and its traditional counterpart, the differences are smaller, though not negligible. According to Shure, the Beta has a more uniform polar pattern across all frequencies, which translates into better control of the frequency response without running into "feedback," something common with condenser microphones.
Before tackling the performance of each unit under test, I would like to comment on the meaning of the "A" that follows each model name. It stands for an improvement in the transformer fitted to the microphones. This output transformer, which is also responsible for the higher price compared with the "non-A" versions, prevents loading losses when the microphone signal is split to different consoles (for example, part of the signal to the monitor console, another to the recording console and another to FOH). Without this transformer, the microphone signal would change every time we split it, something nobody likes, that's for sure.
Beta 58A, the cordless version
The unit we received was also from the ULX series, which means that a wireless receiver (such as the ULXS4) is needed to use it (it is not included). The transmitter is built into the microphone itself, which makes the device reliable and rugged.
As is traditional for the brand, the bottom of the microphone houses the space for a 9 V battery, and two buttons give access to 1,400 programmed frequencies, more than enough to avoid any interference problems. For the lazier among us, the "Automatic Frequency Selection" option automatically offers a choice of frequencies for clear transmission. Unlike other transmission systems, this Beta 58A does not include a mute switch, only the on/off switch; but the truth is that if everything is properly connected, no noise is heard when you switch off the transmitter (as did happen with earlier versions). For added security, it comes standard with the typical cover that makes it hard for the singer or user to switch off the microphone or change the frequency by accident.
With the wireless transmission issue sorted out, let's tackle the microphone itself.
As we have already mentioned, the Beta 58A has a supercardioid design and is intended, like its SM58 sibling, for vocals, both live (surely its standard use) and in the studio. According to the manufacturer, this design maintains the supercardioid pattern across its entire frequency range, which on paper ensures perfect control of feedback, but also minimal coloration.
Since it is designed for vocals, we gladly accept a not entirely linear frequency response (from 50 Hz to 16,000 Hz), which tries to avoid the almost always annoying proximity effect: at 2 cm, 200 Hz is up by barely +5 dB. Its resonant frequency is around 180 Hz.
Continuing with its frequency response, two pronounced peaks stand out at around 4,500 and 9,000 Hz, although we can ignore the latter. Curiously, for many years this 4.5 kHz peak was described as the secret of the Beta series' success. The reality, however, is something else.
In my tests (live and in the studio), even though there were differences (quite noticeable ones) between an SM58 and a Beta 58A in terms of frequency response (but also in dynamics and, above all, signal output, both in the Beta's favor), I usually cut a little around 4-5,000 Hz on the Beta, and adjusted the console's high-pass filter (an Allen&Heath GL4000) in the same way. So the question, in a direct comparison, should be: is it better to cut frequencies or leave them as they are?
The truth is that in these first tests I was using the same voice, which was perhaps not well suited to the Beta 58A's "advantages": everything extra it offered me, I cut back to get noticeably closer to what a "workhorse" SM58 gave me with hardly any EQ changes.
Obviously, it's not that the results were bad, but rather that the chosen singer did not need the Beta 58A's services, except, as I was able to verify later live, for its greater control of feedback, which is definitely better on the Beta.
But when I switched singers, to one who needed more low-end presence and aimed to be a "present" lead vocalist, I dropped the traditional SM58 in favor of the Beta, precisely because of that "extra" it can offer. Here it proved tremendously useful, with a natural, lively and "dynamic" voice, just what I was looking for with that singer.
Beta 87A, give it phantom power
Being reluctant to use condenser microphones live (feedback problems with monitors are much more obvious), the truth is I should change my mind, especially after trying this Beta 58A. Its supercardioid design, more precise than in previous versions, must have a lot to do with it.
Taking advantage of the same situation as in the previous case, already in the "studio" I was surprised by the microphone's good frequency response. With a grip that seems weak but is secure and not very prone to (though it doesn't prevent) handling bumps, I was surprised by the detail and naturalness of the sound. No proximity effect at all, which is welcome in this type of microphone, also for vocals. The polar pattern confirms perfect rejection of any sound beyond 130º.
Obviously, live I had to check what happened with the monitors and, sure enough, the problems surfaced. To get a good level of detail in the sound, this microphone demands generous gain; but in exchange there can be much more feedback, as was the case for me. Curiously, inserting an EQ on the monitor around 5,000 Hz prevented the hiss that heralds the tedious, unwanted squeal, right where the microphone's frequency response shows its first peak. The next one is around 9,000 Hz, although it resists dropping to 0 dB until well past 15,000. As a result, the microphone is much brighter than, for example, the Beta 58A tested earlier.
Conclusion
Although both microphones are designed for vocal use (and knowing that most of us will use them live rather than in the studio), each has its advantages and drawbacks. The Beta 87A offers a much more dynamic, bright and "fun" sound, although it demands precise control of the monitors. When we reduce the gain to avoid feedback, we lose much of the frequency advantages of this condenser microphone.
The Beta 58A will be a perfect ally with certain voices, while with others it will offer no advantage at all over a traditional SM58, except for its better signal output. Being wireless adds an interesting extra. But both, without a doubt, are more than up to the task for a quality project.
