Surviving the Shure Microphone Test Gauntlet: Sweat, Extreme Heat, and More
Shure's meticulous attention to durability can be traced back to World War II when Shure Brothers Incorporated became one of the prime suppliers of military microphones.
For Mr. Shure, this was a formidable responsibility. The safety of military personnel depended upon the proper operation of acoustical devices that bore the name of Shure. Needless to say, with the stakes so high – every component great and small became subject to strict quality regulation.
When World War II ended, Shure decided to keep using military quality specifications. The higher quality specifications resulted in lower scrap rates during manufacturing, fewer repairs, and improved product reliability.
Today, Shure have turned a passion for reliable audio into a science; every product is subjected to a stress-test gauntlet – some procedures described below:
Essentially, we test until something breaks, make any necessary improvements and then we keep going until it can't be fixed anymore. Once we're done, we can be confident the product is ready for what the world can throw at it.
The level of testing is very comprehensive, and involves a brutal quality testing procedure including extreme heat, freezing, synthetic sweat, and, of course, the famous drop test.
It's not just the ubiquitous SM58 either; all Shure products are put through a strict and thorough regime. In fact, the standard is so high that our condenser mics are just as durable.
Let's look at some of the tests in detail:
The Drop Test
Each mic is dropped at least ten times onto a wooden platform from a starting height of six feet. The platform is similar to the floor of a conventional stage, which helps to simulate the typical impact of a mic being knocked over during a performance.
What's interesting about the SM58 is how the grill design acts like a shock absorber when it dents. The grill on your SM58 is actually designed to dent. By making the metal relatively soft, the grill acts like crumple zones on a car to absorb impact and protect the precious capsule inside. Once the grill becomes unsightly, replacements are cheap and easy to replace.
Prolonged exposure to sweat can damage electrical connections, switches, and paint. Therefore, considering live performance can be sweaty business, it's important we test meticulously for sweat resistance.
To determine sweat durability, Shure have developed a custom synthetic sweat solution and products are typically exposed to a sweat bath for up to 48 hours.
In addition to the delightful sweat test, microphones spend time inside temperature-controlled chambers. They look like refrigerators, but in addition to creating freezing cold conditions (below -100C), they can be cranked up to extremely hot temperatures.
All our microphones are expected to survive and still function after the above processes are completed.
HALT is short for 'highly accelerated life test'. It's designed to simulate the life time of a mic – battering it until it breaks. Using the HALT chamber we can see what breaks and then determine exactly which components failed first. The whole process gives us a pretty good idea of how far the product can be pushed, but also allows us to identify areas for engineering improvements.
Finally, a first class stress test also requires first class performance testing. Our anechoic chamber allows for completely isolated testing in a room designed to block radio waves in the same way a soundproof chamber blocks external sound.
The chamber also has zero reflections, which aside from making for a really odd space to be in, also enables us to test products in complete isolation – free from external noise sources and reverberation.
Shure owns the most well-equipped microphone design and testing facility in the world. Currently in our 91st year, an obsession with durability that began with World War II is now so deeply engrained in our culture as a company it's hard to imagine things any other way.