I would like to answer some questions not covered in my review. Please, ask.
What are RE-Zero and RE0
Both belong to those rare dynamic earphones able to compete with armature IEMs in speed, clarity and resolution. Both are on a lean side of neutrality, I would like to have more bass, but I yet to find bassier $100 IEM with the same level of SQ.
They built the same with exception of 4-poles plug of RE-Zero, intended for balanced connection. RE-Zero is provided with converter to the ordinary 3-poles plug, which converter is not convenient for portable use. Shells are metal and sturdy, RE-Zero gun metal color looks better than plain black RE0. Cables are flexible and let you to wear in two ways – both cables down and over the ear.
I prefer both with the tips from Jays (see above), which narrow inner tubes correct some excessive brightness according to my taste. I also removed internal damping foams from RE0 (do not confuse with black protective filters covering the sound tubes). I tried to de-foam RE-Zero but was disappointed with the results, so I put the foams back.
RE-Zero placement in my personal headphone ranking chart
I ranked RE-Zero along with TM5; RE0; ER-4P (custom tips); DT880/250; AD1000. You may find the chart in my Earbuds buyers guide.
Is RE-Zero an upgrade to RE0?
In terms of sensitivity – yes. If your source is weak, like my Sansa Clip+, then RE-Zero plays definitely better.
In terms of SQ, both RE-Zero and RE0 are on par when amped well. They just present different sound signatures. Some will prefer RE-ZERO while others will prefer RE0, and most will have difficulties to choose one.
Sound signatures (with adequate amplification)
RE-ZERO is better in any separate technical terms but mids. Bass is deeper, more linear, accurate and faster. Overall frequency response is more even. Highs are not emphasized and extend higher. Yes, I know that many consider RE0 highs to be a reference. But I think RE-ZERO highs are of better quality. In some tracks, where RE0 produces sibilance, RE-ZERO plays with better details and extension with no sibilance. RE-Zero soundstage is wider, instruments separation and placement have better precision. Speed and clarity are also improved.
RE0 wins in musicality and integrity, it involves more, is more emotional and cohesive. Some mid-bass hump makes rhythmic music more fun. Forward and warmer mids have more body and sound more natural, realistic. Highs are slightly accentuated and more aggressive in comparison to RE-Zero. Soundstage is a bit deeper (surprise). Some ambient noise from live recordings is louder with RE0 and I treat this as a kind of dynamic range compression RE0 provides.
Comparing to ER-4P: RE-Zero is pretty close to ER-4P, closer than RE252. Both RE-Zero and ER-4P are fast, sharp and focused. I compared RE-Zero with custom-tipped ER-4P and I like RE-Zero more (SURPISE!). It presents very similar sound in a smoother and warmer manner, has more body and impact without compromising speed, clarity, bass depth and details.
Comparing to RE252: it is better than both RE-Zero and RE0. It combines strengths of both – it is smooth and fast, warm and clear. It is also has the best bass out of three and more even FR.
With regards to the bass: Total bass weight is the same on RE-Zero and RE0 and depends on specific music/notes/instruments. RE-Zero has stronger deep bass, while RE0 has stronger mid-bass.
Tubes vs SS metaphor: the difference of sound signatures resembles the difference between tube and solid state amps. I may recommend RE0 for tube lovers and RE-Zero to those who prefer SS sound.
Sansa Clip+: RE-Zero is clear winner and a good match. RE0 is too slow and congested with Clip+.
iPod 5.5 gen unamped: I do not like both, my RE252 is better. RE-Zero is dry and lacks bass, probably due to its low impedance mismatched with 5.5 gen capacitor-based output. RE0 is slow, has narrow soundstage and does not separate instruments well.
iPhone 3G: Draw, both plays nice, choose the appropriate for your genres - like RE-Zero for rock, RE0 for pop. Comparing to 5.5 gen, RE-Zero gains bass and warmth. It also becomes brighter than RE0 and this is not good with some music. RE0 gains soundstage width, speed, separation and bass depth.
iPad: both are good match, as with iPhone. And RE-Zero is less bright comparing to iPhone.
Nuforce uDAC: RE-Zero is a good match, while combo of warmer RE0 and warm DAC are veiled in comparison.
Meier Move, Nuforce Icon HDP: I prefer RE0, but this is based on my genres indiscrimination. I see how some may prefer RE-Zero with specific genres like electronic music or fast paced rock subgenres.
General guides for matching: choose RE-Zero for weak or warmer sources, RE0 for powerful and colder sources.
I prefer RE0 for vocals and acoustic instruments, while RE-Zero is better with synthetic or processed sounds.
RE0 is recommended for: pop, jazz, R&B, symphonic music, vocals.
RE-Zero is recommended for: rock, blues, trance, ambient.
Both are pretty versatile, though I consider well amped RE0 as a better all-rounder. It is surprised me being better with classic symphonic music. On the other hand, it is not good with movies, yielding to RE-Zero in imaging, speed, dynamic range and bass depth, which are must for movies.
I thank Fang from Head-direct for providing me with the review samples.
Edited by kostalex - 10/17/10 at 10:26am