
Periodic Audio’s In-Ear Monitors, Mg & Be
Founder and speaker designer Dan Wiggins started Periodic Audio with a focus on portable audio. With a list of credentials that includes transducer design at Sonos and Starke Sound, I was very curious to hear his personally designed single driver IEM (in-ear monitors).
While balanced armature driver IEMs are all the rage (I’ve had a pair for years), Periodic Audio created a simpler design employing a single full-frequency driver without a crossover point. With balanced armature IEMs, you are tuning between multiple drivers for a specific frequency range (think hearing aids), while a dynamic single drivers IEM allow for a more full-frequency response with excellent time-coherence.
These single speaker driver IEMs are available in 3 versions; Mg (magnesium), Ti (titanium), or Be (beryllium). The properties of the speaker drivers, like mass stiffness, and electrical conductivity differ for each metal chosen. In fact a full frequency response chart and specifications for each model can be found on their website. For the sake of this review, I auditioned the magnesium and beryllium driver versions directly connected to an iPhone 6.
Unboxing these IEMs revealed a variety of silicone and memory foam ear-tip size options, adapters for both 1/4 in stereo jacks and an airplane adapter (man those airplanes need updating). I was even told you can experiment with the ear-tips and once you settle on the type/size you like they’ll send you some extra ones- cool customer service. These IEMs are made of polycarbonate with the single driver, port, and hard-wired cable. While I was initially concerned about the build quality with these IEMs, after using them for over 6 months (3 days a week at gym), I am happy to report they are quite sturdy little buds.

All models include ear tips, 1/4 stereo adapter, & airplane adapter
Mg (magnesium): The entry model ($99) is constructed of 96% magnesium drivers with a N48H neodymium magnet. Everything from the drivers to the volume of the front and rear housing were designed and tooled in-house.
Using the magnesium drivers for some time revealed a favor for mid to higher frequencies, and does so in a way that tips the listener to a revealing top end. The drivers produced an even bass response, but some of the authority and fullness of the deepest bass was bested by the Beryllium drivers. While the mid to higher frequencies are pronounced, I would not call them overtly bright or harsh. Soundstage is decent, but not amazing (yes, I know they are IEM). Articulation of musical attack was good but tighter with the Be driver.
Be (beryllium) ($299): The custom top model from Periodic Audio employs a 100% pure beryllium foil diaphragm with a bonded PEEK surround and N48H neodymium magnets.
Moving onto the beryllium drivers was a major step-up, in every way. Bass became extended and powerful, middle and treble frequencies were better balanced and defined. The control of these drivers allowed for a more intimate sonic view of the mix. The soundstage also had a major benefit from the beryllium driver material- nuanced synth sounds from Herbie Hancock now popped out of hard left and right with piston-like precision.
While headphone amps and DACs will certainly improve these IEM’s sound, I was happy to find they were easily driven by my iPhone 6 heaphone jack/amp.
If I had to knock points to either IEM, it would be the quality and presentation of packaging. While they are supplied with a screw on circular case(cord tangle issues), maybe a zippered pouch would be preferred. A small red dot differentiates right from left ear buds, but man is that dot tiny- can we make it a wee bigger? While it may be obvious I preferred the beryllium driver, let me be clear that the $99 Mg in-ear in no slouch. I recommend taking a listen to each model at the next audio show for your personal preference.
Periodic Audio has managed to bring some thoughtful and musical designs to the in-ear monitor market. This materials based approach offers the consumer options and an education. Real science, real engineers, real transparent.
Anatomy of a Periodic Audio In-Ear Monitor
-happy listening