Headphone Reviews

Sound Quality and Intended Application
I'll quote Ronny Tsai, President of Spider Cable, on the intent of the Realvoice IEM:

"We didn’t name our earphone 'realvoice' by accident, it can represent singers’ true voice."

The Realvoice IEM was designed to bring out the natural timbre of the human voice. Given my penchant for neutrality, and vast experience listening to "voiced" headphones that sound miserable, I was highly suspicious. Well, color me surprised, these things sound great.

With a generally warm tilt (bass accentuated, treble rolled off) the Realvoice is a pleasure to hear. The accentuated bass is not overdone and is well extended. Though slightly loose sounding at times, the bass remains reasonably articulated and well integrated into the mids. The treble is somewhat reduced relative to the mids, but by no means lacking. All the details are well preserved and articulated. The mids are downright glorious, and really do bring out the natural timbre of the human voice. Though slightly warm, it's hard to characterize the sound of these cans as "colored," rather, they are relaxed, comforting, and tremendously pleasurable for a headphone at this price. The Spider Cable Realvoice is definately one of the better sub-$100 IEMs I've heard.

Being a lower cost headphone with headset features, I listened extensively on my iPhone and Droid. I spend a lot of time streaming Pandora while I write, and the Realvoice headphones made streamed audio off my phones a distinct pleasure. Their gentle but articulate highs were never screechy, and they really brought out all the best things in the music without calling attention to the foibles of compressed audio.

Measurements

On the upper corrected frequency response graph, the overall warm tilt of these cans can be seen with the bass elevated on the left and treble reduced on the right. The bass emphasis is mild compared to many IEMs I've tested, and shows good restraint on the designers part. It's interesting to note how flat the graph is between 300Hz and 2000Hz. On many IEMs the bass will start rising at a much higher frequency and net a muffled or murky sound. I think the FR curve for the Realvoice indicates how they delivered a balanced midrange so nicely. The spike at 9kHz is likely an ear canal resonance, and is fairly common in headphone measurements. During pink noise listening tests I can usually hear spikes in highs; I didn't hear this spike during listening tests.

The 30Hz square wave response show the high frequency components of the leading edge lower in level than the humped up top; this indicates a warm sounding headphone. The full length of the top of the waveform remaining well above zero indicates good bass extension.

The 300Hz square wave response and impulse response shows a headphone that may be a tad slow to react, but also shows significant lack of ring and noise artifacts that lead to harsh or grainy sound.

THD+noise data shows a low distortion headphone with very good power handling capability as indicated by the 100dB traces falling below the 90dB data.

With a very flat impedance curve at 18 Ohms and needing 24mVrms to achieve 90dB levels, this headphone will be driven quite easily by portable payers of all types.

All told, this is a very respectable set of measurements for a headphone of this price. Very.

Summary
I was surprised that this somewhat odd design fit so comfortably in my ears, and was tickled pink to hear the great sound of the Spider Cable Realvoice once inserted. It's not often you get to hear such tastefully tweaked headphones that do so many things so right ... especially at this low price point. I heartily recommend these tasty little cans.

Resources after the video!

Spider Cable website and Realvoice product page.
Head-Fi threads on the Realvoice here, here, here, and here.