Last modification: 01/19/08 19:26

Dallas' Gear Review

 The Edirol R-09 Flash Field Recorder
Sound Professionals SP-TFB-2 In-Ear Binaural Microphones


My Edirol R-09 just came in, and being an early adopter I thought I'd do a few comparisons between recording with the unit's internal mics vs. Sound Professionals' SP-TFB-2 in-ear microphones. Besides being stealthy and cheap, I was impressed by the quality of the sample live recording for this stereo plug-in-power electret condenser pair on the Sound Professionals website. It seemed like a good idea indeed to pick up a pair, as I could then stick the Edirol in my pocket for recording purposes and not have to worry about ambient noise from rustling clothes, etc. Plus, this is almost certainly the cheapest way to perform holographic (dummy head) recordings - trés unique!

Before we continue, take a look at the polar pattern & frequency response graphic for the EDIROL's built-in mics in the graphic above. This is from the back of the box - where, exactly does the "flat omnidirectional frequency response" come from? There's like a total disconnect happening there! At least you know that the lows and highs aren't gonna get shortchanged, LOL - maybe that's a good thing.

OK. On the left, what we have is a 10-second burst of mono white noise played over a pair of Mackie HR824 nearfield reference monitors and recorded at 24-bit using both the internal and external binaural microphones from a distance of two feet. On the right, we have the sound of a CD reference (in this case, Megadeth's Family Tree from Youthanasia) similarly recorded by the Edirol, so you can hear what the transfer curves sound like in the context of a recorded piece of music.

What we see in Fig. 2 is a curve that ideally should be matching fig. 1, although considering the ~.7dB octave slope from 160Hz to 5.2K, that doesn't seem to be the case here. Fig 3's more complex shape has much to do with the size and shape of my ear, but Fig. 4 (recorded externally, not in-ear) is not so simple either!

Purple line - 10 sec. time-averaged mono white noise
Red line - captured from distance of 2 ft, post-normalization
Recorded Music Capture
Reference Track
R-09 internal microphones (front edge aimed at speakers)


Recorded Result
Sound Professionals SP-TFB-2 Binaural Microphones (std sensitivity)

Fig. 3 (in-ear)

Recorded Result

Fig. 4 (outside ear)

Recorded Result

It doesn't take golden ears to tell that the binaurals handle their low-mids well in-ear, at the expense of some bass response - but outside the ear? Impractical, but yowza! While these tests are not intended to be a substitute for real lab analysis (the artifacts of my listening environment do affect this all somewhat) - but it's enough to build a case that the SP-TFB-2's can sound pretty decent. And the Edirol R-09 itself? Right now it may be the only real game in town at this price point, but that's going to change. The manufacturing cost of this box is almost nothing compared to an iPod or a Hi-MD MiniDisc, the mics are just so-so and it offers neither balanced or digital inputs nor a built-in socket for camera or microphone stand. It's also a little too big to cram inside of a cigarette box or a deck of cards, dammit! $275 should be the price point, but until Roland's rival M-Audio drops its price on the $399 MicroTrack it seems like the only game in town. :D

Dallas' Gear Rating : (out of 5)


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