OK, I plucked down $290 for a pair of XBA-4SL (Japanese version with 0.4m short chord w/ straight mini-plug + 0.9 m extension). I got the Japanese version because of the short cord length which works better for me. Unfortunately, I found it unlistenable.
First, let me be fair to the XBA-4 and validate its virtues. It is has very good bass extension without any boom. Despite what the term "superwoofer" may suggest, there isn't a bass overtone. The bass is simply linear and going as low as you can ever hear, but without any over emphasis. The mids and treble are extremely detailed and not colored. I do find the vocals a little recessed and a little cold, but that is not entirely a bad thing and perhaps more accurate than the phones that bring it up front and warm it up. I prefer expanding foam inserts, but I can live with the single silicone flange with sponge stuffing that Sony prefers. There are enough sizes that you'll find a good fit unless you have ears of a mouse or elephant.
However, none of the pluses make the XBA-4 listenable. The XBA-4, for all its linearity, neutrality and accuracy has one fatal flaw -- for all its sensitivity the XBA-4 picks up all the flaws of an audio source more than it does musical detail, and emphasize the normally inaudible or unobjectionable flaws to irritating and intolerable levels. There is an ever persistent hiss on most tracks -- very much like tape hiss you'll fine on cassette tape except its 3 times louder, higher in frequency and loud enough that it never disappear even when the track is not on a quiet passage. For those of you old enough to remember, it's like a Dolby C NR processed tape without Dolby C NR turned off in the player -- amplified 2~3 times. Sharp, loud, metallic, unmissable, ever present. "Hhssssstssstssstssstrrrsstt". On top of the hiss, you will also find every little pop or crack from an audio track that is normally recessed and unobjectionable on the center stage and impossible to ignore or filter out. Every compression artifact from mp3/aac file or electronic noise less than stellar playback sources like a laptop is also brought out with great prominence. On the laptop you can hear and identify all the electronic noises -- the LCD backlight hum, the SSD access traffic, even the additional electronic noises from when you slide you finger over the touch pad. Even when nothing is playing there is always the background amplifier hiss the moment you plug the XBA-4 into anything... anything at all.
Now, this may be clinically accurate and truly reflective of the quality of the source. But, I am not interested in a tool for exposing, emphasizing and analyzing every flaw in my sources. I am interested in enjoyable music. And, that means a set of speakers, canal phones or cans should make below average recordings sound good and good ones sound stellar. The XBA-4 succeeds in doing the opposite. It makes average recordings unlistenable and good ones sound flawed. Yes, it does just fine with the near perfect tracks that comprises 5% of all music collection out there. But that means that it can at best be something I pull out once a month when I come across something I want to vet for nomination to the ranks of "perfect audio recordings".
I alternated listening to the XBA-4 with a few other audio transducers. A noise cancelling NC300 dynamic canalphone, a pair of (if you guys remember) MDR-484 ear buds, Ety ER-6p, NC300 noise cancelling canal phones, a room setup consisting of a Naim NAT5i Amp with Mission Speakers and the factory Harman-Kardon stereo in my 2005 W203 C55 sedan. I made it a point to listen to the same tracks on all. I also tried the XBA-4 and the various earphones direct from the laptop, via my Sony Xperia phone, via my PSP, via the iPod, via an old WM-DD9 Walkman... with and without an iBasso D-Zero and Total Bithead USB DAC/Amp. Everything else sounds more enjoyable than the XBA-4, and nothing I tried can subdue the hiss and artifacts enough to make the XBA-4 unobjectionable. Finally I pulled out the 4-year old but unused ear buds that came with the iPod. Even that sounded better! Yes, it's coarse, its mushy and its not particularly high resolution and generally lousy. But it is at the minimum not hissing and irritating as hell!
Learning to like the XBA-4 means learning to perform DSP in your brain and filtering our the ever persistent and super pronounced hiss, pops, cracks and other artifacts you'll find hiding in most recordings. You must constantly tell yourself -- listen to the instruments, don't listen to the hiss, listen to the singer, don't listen the crackles, listen to this, don't listen to that. It's a very tiring task and worse than trying to listen to music in a crowded market place because, quite honestly, background conversations and bazaar chatter is less irritating than hisses, pops, cracks and amplified audio artifacts!
Edited by DwightLooi - 5/8/12 at 5:59am