Review: RBH EP1 In-Ear Headphone

“So when are you guys gonna do headphones?” I jokingly asked the staff of RBH Sound when I visited them at January’s CES show. A boutique speaker company, RBH focuses on the sort of relatively high-end products that independent dealers like to sell. I never expected they’d join the mass-market speaker companies now crowding into the headphone market. But while I expected the RBH guys would scoff and roll their eyes at my remark, I instead encountered an uncomfortable silence and averted gazes. Something was up, I knew.

Now we all know what that “something” is: the EP1 Noise Isolating Earphones.

The EP1 looks like a cross between the Skullcandy Titan and the Phiaton PS 20, both of which I happen to like a lot. Like the PS 20, the EP1 has a large flange that’s intended to help block your ear canal for better isolation. To further enhance the EP1’s ear-plugging capability, RBH includes silicon ear tips in three sizes, plus a set of Comply T-400 foam tips in medium size. Thus, your chances of getting a good seal—and as a result, the best possible sound—are about as good with the EP1 as they’d be with anything other than a custom-molded in-ear monitor.

The sound of the EP1 better be special, because on the surface, there’s nothing interesting about it. It comes with a generic spring-snap leatherette case. It doesn’t offer iPhone control or an inline microphone. It doesn’t come in a variety of designer colors. And the fabric-covered cord snarls more readily than your grandma’s Chihuahua. I can easily find a similar level of headphone luxury for $39, maybe even less.

Unfortunately, I didn’t have a chance to convene my usual headphone testing panel for this review, but I’ll toss the EP1 into our next session and add their opinions later.

The dog-walking test

I got my first impression of the EP1 while out on a quick walk around the neighborhood with the schnoxie I’ve been keeping for a friend. I often put on a new set of headphones for these walks just to get a rough idea of what they sound like; by the time we get around the block I usually know whether a headphone is above, below, or right about average.

This walk was a little unusual, though, in that I stopped to revel in the EP1’s sound quality even more often than the schnoxie stopped at trees to look for squirrels.

“Spirit,” from jazz guitarist Mike Stern’s Voices CD (stored in 256 kbps MP3 on my iPod touch), quickly reveals the differences among headphones. In the tune’s mix of piano, drums, funky electric bass, Brazilian-style vocals, and Stern’s trademark reverby, twangy, ultra-legato lines, there’s something to screw up almost any headphone. But the EP1 didn’t screw up. I kept stopping during our walk to revel in the big, ambient sound the EP1 delivered, and that it didn’t rely on the usual trickery (like boosted treble) to get that effect.

When we got home, I had the chance to compare the EP1 with some of the other in-ear monitors (IEMs) we’ve recently raved about. While I and our panelists liked all of these headphones a lot, the EP1 made them all sound slightly flawed. Through the EP1, I couldn’t find anything to complain about in the tonal balance or the portrayal of the various instruments in “Spirit.” But through the B&W C5, the piano sounded rather thin. Through the Audiofly AF78, the treble — the cymbals and snare drum, specifically — sounded too prominent and the bass seemed thin as a result. Through the Rock-It R-30, the snare sounded confined and tiny, more like a toy drum than the real thing.

It’s in the drums where the EP1 gets things especially right. So many IEMs emphasize the cymbals, or damp the cymbals, or make the cymbals and snare sound like they were recorded in a trash can, or make the kick drum boom, or kill the kick drum’s impact. But on Wes Montgomery’s version of “What the World Needs Now,” the whole kit seemed well-balanced and accurately portrayed, with perhaps just the slightest upper-treble emphasis bringing out the cymbals a bit, and the EP1 providing full but tight bass to keep Montgomery’s solid groove going.

Enough with the jazz, already. The kind of music most people actually listen to on a regular basis also sounded great through the EP1. In Led Zeppelin’s “Dancing Days,” I got the full sonic picture of John Bonham’s perfectly tuned drum kit, Jimmy Page’s wailing, Moroccan-influenced guitar lines, and Robert Plant’s whining vocal.

The only thing I might have wanted from “Dancing Days” was a little more of John Paul Jones’ bass. I doubt many people would consider the EP1’s sound thin, and it’s fuller-sounding than any of the IEMs I mentioned above, but it’s definitely tuned for accurate, rather than pumped-up, bass.

(By the way, I used the largest of the silicon tips — I have a love/hate relationship with Comply tips, and while they work wonders on my Blue Ant Q2 Bluetooth headset, they didn’t give me enough bass with the EP1.)

The EP1 treats vocalists especially well. Singers who often sound shrill to me through IEMs, like Joni Mitchell, sound studio-smooth through the EP1. I kept hitting repeat on “Free Man in Paris” ’cause it just sounded so great with these IEMs. Not only did all the instruments and vocals sound natural and well-balanced against each other, the sound had a more open, compelling sense of space than I’m used to hearing through IEMs.


I measured the EP1 using a G.R.A.S. Type RA0045 ear simulator, a Clio FW audio analyzer, and a Musical Fidelity V-Can headphone amplifier. I used the supplied medium-sized silicon tips, which fit the ear simulator best. I inserted and reinserted each earpiece several times, and settled on a position for each that gave the most representative result.

The EP1’s frequency response measurements suggest it might sound a little bassy to many people. With most neutral-sounding headphones, there’s a fairly narrow boost somewhere between 2 and 5 kHz, but with the EP1, the entire band is boosted. There’s also a bigger-than-usual bass boost centered at 45 Hz. Perhaps the broadness of the boosted treble band counteracts the rather large bass boost. Adding 70 ohms additional output impedance to the V-Can’s 5-ohm output impedance to simulate the effects of using a low-quality headphone amp had almost no effect, boosting bass by less than +2 dB at 20 Hz.

Total harmonic distortion (THD) at 100 dBA is among the lowest I’ve measured, running below 1% at all frequencies except for a small, narrow distortion peak of 2% centered at 4.7 kHz. Impedance is nearly flat, averaging 18 ohms except for a slight rise to 20 ohms at 20 kHz—plus a small impedance peak at 4.7 kHz, right where the distortion peak appeared. Coincidence? I think not.

Isolation is above-average for an IEM, dropping from -10 dB at 100 Hz to -24 dB at 1 kHz to a maximum of -40 dB at 13 kHz. However, I still don’t feel that my measurements capture the full isolating effects of the large flange. Measuring with the ear simulator (as I did in this case) bypasses the flange acoustically. If I use the full ear/cheek simulator, with the fake rubber ear, the EP1 measures no better than any ordinary IEM, but that’s because the eartip doesn’t fit fully into the rubber ear.

Sensitivity measured with a 1 mW signal at the rated 16 ohms impedance is 101.5 dB average from 300 Hz to 10 kHz, 103.6 dB average from 300 Hz to 6 kHz.

Bottom Line

As I always say, it’s tough to give a totally enthusiastic recommendation of any headphone — especially an IEM — because individual impressions vary so much. However, I’m stoked enough about the EP1 to say I haven’t found a dynamic IEM I like better. My only caution is to those who like headphones with powerful bass, because while the EP1 doesn’t sound thin, I doubt anyone would describe its sound as “kick-ass.”

The EP1 is pricey for what it is, but I think its sound quality makes it worth the money.