Reviewed on: SoundStage! Solo, April 2023

I measured the Campfire Audio Orbit earphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and an Audiomatica Clio 12 QC audio analyzer. A Reiyin WT-HD06 Bluetooth transmitter was used to send signals from the Clio 12 QC to the earphones. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. Note that I’m unable to do spectral-decay measurements with most Bluetooth earphones because of the latency. If you’d like to learn more about what our measurements mean, click here.

Frequency response

This chart shows the Orbits’ frequency response. See that peak around 5.5 to 6kHz? If you shifted that down by 2.5kHz, this response would look fairly normal. I’m sure that sometime in the last ten years I’ve measured something with a response that looks like this, but I can’t recall what it was or what it sounded like. My guess is that these earphones will sound recessed in the upper midrange, which is where the definition and clarity of human voices happen.

Frequency response

This chart shows the Orbit earphones’ response compared with three true wireless models that have gotten good reviews here. (Models with noise canceling are measured with noise canceling activated.) Note that the KEF Mu3 earphones come pretty close to the Harman curve. It’s easily apparent how much less upper-midrange energy the Orbits have versus the other earphones.

THD

Here’s the THD vs. frequency, measured at 90dBA; I could barely get the Orbits to play any louder. Note that I used discrete sine test tones in one-octave steps rather than my usual sine sweep, because I wasn’t able to find a combination of settings on the Clio analyzer that could compensate for the Bluetooth latency. The distortion is very high at 20Hz, but it’s down to inaudible levels by 40Hz, and very few music recordings have much content below 40Hz. It’s also fairly high at 10kHz, but considering that the first distortion harmonic will be at 20kHz, you won’t hear it.

Isolation

In this chart, the external noise level is 85dB SPL (the red trace), and the numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. Weirdly, in the simulated pinna of the ear/cheek simulator, I got better isolation with the supplied silicone tips than with the supplied foam tips, but in a real ear, the results may be different. I added the Bose QC Earbuds II to show how a good set of noise-canceling earphones compares.

Latency

Latency, measured with the Reiyin transmitter, was typically around 245ms.

Bottom line: The Orbit earphones definitely have a quirky frequency response, which research suggests the majority of listeners probably won’t dig, but Campfire intentionally doesn’t conform to any one target curve, and crafts different sonic profiles for its earphones. It’s up to the listener to decide whether they like this sound.

. . . Brent Butterworth
brentb@soundstagenetwork.com