Seeing as the TH-X00 is going through it's second drop on Massdrop, and will be close to selling out by the time I press "Submit", I thought I'd write a review to try and explain what all the craziness is about.  
 
The TH-X00 are a Massdrop.com exclusive headphone designed by Fostex for Massdrop.  You cannot purchase these headphones anywhere but from Massdrop, and currently there are only 2000 of these headphones in existence, and as of May of 2016, 1000 additional copies will exist.  So scarcity helps build the hype around these gorgeous natural mahogany cupped semi-closed cans.  On the other hand, there wouldn't be any hype or discussion at all if the TH-X00 sounded like garbage.  
 
I picked up a pair of these after reading a rave Head-Fi review about the amazing bass response these headphones achieve-- and then the "must act now" and "exclusive" language kickstarted what I call my "Big Dumb Guy" (BDG) gene and I just HAD to have them.  Right?!  I got serial number 1166.  That BDG gene has cost me tens of thousands.
 
On the face of it, other than the beautiful mahogany, they're fairly ordinary headphones.  The pads are pleather and they're a bit cramped, the cable cannot be replaced without a solder job, you have to use a ridiculous 1/4 inch step-down jack to use them with an iPhone or Astell & Kern player or laptop, and the case is just a basic bag.  That-- is where ordinary stops.  Plug them into any reasonably decent source, and you're in for a ride.  Plug them into a great source, and you're going to hear something very special.
 
The TH-X00 are insanely efficient.  At just 32 ohms they're compatible with any source you can find, which is why the 1/4 inch jack makes no sense.  No matter.  I'm pairing them with the AK240 and Chord Hugo... yep... $3500+ in source gear for a $400 headphone.  Trust me, it's worth every penny.  These cans scale extremely well with the source.
 
Because the speaker tech is trickle down from the basshead Fostex TH-900 and TH-600, you would expect a lot of bass, and these don't disappoint.  Where the TH-X00 jumps ahead (in my opinion) is they tightened up the bass and removed most of the bloat that often muddies the lower frequencies.  Yeah, there's still a little bloat, but it makes the headphone fun-- it has swagger.  I love headphones with an attitude.  The bass is rich, deep, and powerful (even explosive at times), without losing too much definition as basshead cans tend to do.  This was a tuning choice by Massdrop, and I think a wise one.  Where the TH-X00 falls behind the upper price range cans (say, the Audeze LCD-3) is bass speed.  But just the fact that it's worth comparing the bass to any LCD, at just $400 dollars, it says a lot about how good the bass is on the TH-X00.
 
The highs are open, but not extended.  At first listen, I thought the highs were muted and I was almost disappointed.  But putting on Supertramp's COTC-- "Dreamer" the triangles ring very clean and clear-- the harp on the beginning of "School" is crisp and even airy-- but without a lot of brightness or sparkle that sub-$500 dollar headphones amp up in the name of "fidelity".  It's a very unique sound-- because it gives the headphone a slightly dark signature like more expensive models, but you're getting the full frequency range.  
 
Soundstage is better than you might expect, and I'm guessing this is because the design is only semi-closed.  It's no HD-650, but there's enough width to give you a nice presentation and there's above average imaging and definition, too.  
 
So where does this headphone fit?  I have no problem calling it the best $400 dollar headphone on the market.  In fact, I think it's the best sub-$500 dollar headphone out there.  I also own a Bowers & Wilkins P7-- which I place well ahead of the famed Sennheiser Momentums, and I seriously looked at the HiFiMan HE-400S-- which is a bargain at $300.  But the TH-X00 sounds like a $1000 to $1200 dollar headphone to me (maybe higher), and given its scarcity, it's easy to see how nearly 700 of the 1000 units in the SECOND drop have been claimed in just 18 hours.  My P7's have been gathering dust since November.
 
My usage-- They're a bit bulky, but I bought a travel case and I take them with me to work on days when I know I have paperwork and on the road when I travel.   I took them on a recent flight to Dallas-- despite the semi-open design, very little sound leak on an airplane, my neighbor didn't complain at all.  Paired with the AK and Hugo-- I'm getting hammer of the gods for in-flight entertainment.  These cans are addictive.  
 
I don't use them much at home, mostly because I have the HE-1000 which get nearly all of the listening time.  But if I'm in the mood for lower level listening-- I will reach for them.  The other point I'd make is this:  They're fun headphones.  They're not analytic.  I'm not doing reference-level listening, I'm kicking back and enjoying music.  With the HEK, I find myself searching for tracks that show off what the headphone can achieve (which, to be fair-- is reason enough for owning them-- they're my favorite headphone on the planet at the moment).  With the TH-X00, I'm able to let go of the technical prowess and rock out.
 
If you're lucky to pick up one of the remaining 300 in this latest drop, you're in for a heck of a ride.  
 
UPDATE:  Massdrop has just released a variation on the TH-X00 in Purpleheart wood.  I did BDG it again, and picked them up.  They don't arrive until August of 2016, but I'm such a fan of the original, I can hardly wait to hear the improvements.
 
At CanJam LA 2016 I had the opportunity of A/B listening with the Fostex TH900.  The biggest difference is detail.  The TH900 were articulate during complex passages, the TH-X00 sort of glossed over those passages.  So for $1000 bucks you add detail, a bit more flash on the cup, removable wires, and an arguably more complete sound.  That's not to diminish the TH-X00.  It's still a terrific everyday headphone, and I brought them to CanJam to let my friends have a listen as I went from vendor to vendor-- I never heard a bad word about them.  

I was a happy P5 owner and I've been a huge B&W fan for quite a while.  Their products always fall into that "Bose done right" category.  B&W makes the consumer grade products which Bose SHOULD be making.  Extreme high quality without sacrificing sound quality.
 
Enter the P7.  I'm happy to report with the P7, B&W took everything they learned in the making of the P5, and improved upon it.  The prime difference between the P5 and P7 is the P5 is on-ear, where the P7 is over-ear.  The P5 were very picky when it came to ear placement.  You could get 5 different sound signatures out of the P5 by simply changing how they sat on your ear.  The P7 does away with all that fiddling.  Put them on, and they're good to go.  
 
But not right away.  The P7 required significant break in before the bass came to life.  
 
Out of the box I was immediately impressed by the build quality.  This is another high-end assembly by B&W.  The attention to detail is obvious.  Highest quality leather ear cups and head pad.  Beautiful chrome skeleton and brushed aluminum.  These are remarkable headphones, and like the P5, they hug your head like pillows without any fatigue.  They fold up nicely and come with a largish case.  If you're looking for super-compact travel phones, these might not be for you.  The other note on comfort and fit-- if you don't like phones touching your ears at all, these aren't for you.  They are close on the ears.  Sound isolation is excellent.
 
The sound quality is what I call glossy.  Bright without sibilance, punchy without bloom or bloat.  The sound is cohesive in the extreme-- very musical-- but there's not a lot of air between the instruments.  The soundstage is decent for a closed headphone, but it's not of the HE-500 or HD-650 class a few hundred dollars up the road (and open as opposed to the closed P7 design).  I like to call the sound 'winning' at first listen.  It's an intimate appeal, I was drawn to the sound signature immediately and if you have nothing of a higher end to compare them to, you're likely to fall in love.  Switching over to the HD-800 and you immediately hear the lack of air.  Then again, the HD-800 is $1000 dollars more and is open backed.
 
The P7 is easy to drive.  They can be used right out of a smartphone, but obviously benefit from decent amplification.  My Pico Slim matches up very well with them and I imagine the Woo Firefly or even a Burson is probably the ultimate pairing for this headphone.  My WA5LE was overkill.
 
I'm currently using the P7 at work, where I spend long hours wearing headphones.  They've all but replaced the ATH-M50, which I rarely turn to anymore (at 1/3 the price).  I've not done direct A/B comparisons with their nearest competitor, the Momentum, but I've heard both independently, and I favored the P7.  I consider the P7 to be best in class at the consumer grade $400 price point. 
 
If I were considering the Momentum, or a Bose active noise reduction headphone, I'd definitely steer you to the P7.  You will be rewarded.

I'll make this brief.  Apogee is well known for doing quality interfaces for musicians and engineers.  Their Symphony line is really 2nd to ProTools when it comes to quality.  
 
I purchased the Duet2 to be a way into my system for doing voice overs using its mic pre.  I also wanted a nifty interface for my Avid Symphony editing system feeding my Genelec near-field monitors.  On that front it does what it's supposed to do.  
 
I was hoping it might make a good DAC for listening.  Unfortunately this really doesn't run with the high end equipment.  It raises an interesting point, though.  Most musicians use gear to record the music which 'wows' us utilizing technology most of us would deem inferior.  
 
We shove signals through silver headphone cables and the highest end tube gear to reproduce sound which originates through copper cables, cheap guitar pickups and less than perfect recording interfaces. Quite ironic.  
 
The Beatles didn't record on 4 track tape (yes, tape) until the late '60s.  Some of their most complex works were done by playing taped recordings live in the booth and old-fashioned mixing.  Legend has it that Queen, in recording their masterpiece "Bohemian Rhapsody", had recorded so many overdubs on their master that Brian May at one point held the tape up to light and realized they'd nearly worn the tape through.  A quick mix-down to fresh tape saved their work.
 
So what does this have to do with the Duet2?  Well as a recording interface, it does a decent job.  I've done a lot of vocal and voice over work using this small box, some of which you've probably heard on the airwaves and didn't blink twice.  But on critical playback in my high-end rig,  it sounds like garbage.  It's both noisy and colored.  Irony indeed.
 
It serves my edit bay just fine.  And the design is snazzy.  Just don't plug it in and expect to hear magic on your Audeze LCDs.   
 
 

Not that there haven't been a hundred thousand things written on this most-controversial headphone-- but what the heck are we here for if not to give our opinion, right?  So sit back with a cup of coffee, while I'll tell the story of my HD 800 experience.
 
It's funny-- there's a growing Apple-Microsoft type environment growing in the Head-Fi community.  It's between HD 800 owners and fans, and Audeze owners and fans.  If you read any forum with the omni-present headline "Which Headphone Should I Buy?" the two sides make themselves known in subtle ways.  "Well if you're looking for comfort, you can't go wrong with the HD 800," writes one post.  "Way more comfortable than the LCD-2."  Next post: "What?  You're crazy!  I've had my LCD's cranked on my head for like 10 hours today.  Look!  There's still on my head and I didn't know it!"  "Well Sennheiser has been around for seven hundred years.  You know they'll be here after the world explodes and you need new earpads after the firestorm scorches them."  "At Audeze, they hand craft every single component and skip Valentine's Day because the love goes into their products."  And on and on the debate goes. 
 
Point is-- Everyone is going to be predisposed to one type of headphone or another.  I haven't owned an Audeze headphone yet.  I will in the next year or two.  Right now I'm still finding the edge of the envelope for the HD 800, and it's getting interesting.
 
I started my Head-Fi journey in the shallow end.   I needed wanted a custom in-ear headphone which really blocked out sound, so I stumbled across Ultimate Ears Reference Monitors and went through the process of acquiring a pair.  Amazed by the fidelity, I started looking for opinions and found Head-Fi and Headfonia-- which led me to the Slim Pico Amp.  Impressed, I thought I'd try an open ear set of cans for home-- so I bought the HD 650.  Then I thought-- let's put some power down-- so I bought a Burson 160D.  Great, but lots of treble-- let's find a smooth tube amp!  Enter the Woo WA6.  Then I rolled a thousand+ dollars in tubes into it-- and bought the HD 800.  You can already see-- this story isn't going to end well. 
 
The HD 800 out of the Burson and the WA6 were a subtle upgrade over the HD 650.  The bass was certainly tighter, the soundstage wider, but honestly-- the change between the two wasn't all that remarkable.  Still, I kept the HD 800 figuring I can scale them up if I wish, and they were more comfortable on my head than the HD 650-- so the HD 650 were sold so my wife wouldn't murder me.
 
Sure, there were other headphone purchases-- Audio Technica ATH-50s (those still live at work), Grado SR225, Beats (yes, Beats-- wanting to see what the fuss was about-- that's another review), and some in-ears-- Shure SE425 (still for sale), Klipsch, HifiMan, among others.  But the main focus now was my home rig and bringing the best out of my HD 800.
 
The WA6 tube rolling experiments got all the way to a NOS 1957 GZ34 rectifier with a metal base, which cost around the price of the amp-- The HD 800 responded every step of the way.  The bass deepened as the headphone broke in, I upgraded the cable to Toxic silver (exciting another debate over whether pure copper is a better match for the HD 800).  Things were improving but the knock still was that the sub bass wasn't kicking, and the highs out of the Burson made that combo particularly bright to my ears-- damn near to the point of sibilance.  
 
In October, one Head-Fier suggested-- maybe you should think about more power for the HD 800, suggesting a move to the WA6-SE.  I started an eBay search.  This wasn't going to be pretty.
 
After losing a few auctions-- something really bad happened.  A Woo WA5LE appeared-- and no one was bidding.  Yep.  That was the winner.  $1800 dollars later I started looking for FedEx trucks everywhere I went.  
 
This was a major change in the HD 800.  The full range of the audio spectrum was now pumping through my skull.  It was like getting a much-needed pair of glasses after years of squinting.  I never realized how power hungry this headphone really was.  Sure, I can drive the HD 800 with a Fiio E17, they are efficient headphones, but to bring this set of cans to life, it wants pure, clean power, as much-- and as clean-- as you can muster.  
 
I'm not talking about a marginal improvement anymore.  Here's my best analogy:  Say I purchased a Ferrari.  I get behind the wheel and take it for a spin.  Well, it's a Ferrari, so I'm going to be impressed.  What I didn't know-- is that the car came only with a four-cylinder engine.  And while I thought I was getting this good performance, when I dropped a (edit) Prat & Whitney jet engine in, suddenly you are holding on for dear life.  Everything about the car's characteristics changed.  The car can move with the four-banger, but it was really made to handle a lot of power.  Same goes with the HD 800.
 
Now here's another problem with this new system-- every musical flaw is up front.  Putting MP3 files through it-- you hear every artifact and dropout.  It's brought the worst out of the Burson's DAC stage.  So much so-- I'm now selling the Burson for a cleaner DAC.  
 
Stepping back for a second-- you have to wonder-- what was wrong with the HD 650 and the WA6?  Nothing.  I'm crazy.  I admit it.  
 
But for folks who complain that the HD 800 lacks sub-bass, my first question from now on is going to be-- What are you using to drive it?  Because with the right power, you understand why this is a $1500 dollar headphone.  It's the closest thing I've ever heard to sonic perfection-- yet I'm still rolling thousands of dollars in tubes through the WA5LE, to see where the edge of the envelope is with the HD 800.
 
 
 
 
 
 
 

The HiFiMAN RE-272 are the best sounding pair of non-customs I've put in my ear.  Period.
 
I wanted to try a pair after reading favorable reviews around these parts, and I'm glad I made the journey.
 
The bass is slightly accented without overdriving.  The high end detail doesn't suffer at all.  It's a bit of a closed in sound-- but these are full range earbuds.  They have good detail and they're decent at delivering transients.
 
My main pair of buds are UERMs, and the supreme balance and detail put them in a much higher class (both in sound and price).  But I'd say if you're looking for great sound in a universal fit earbud, look no further.
 
On my ears, these need to be pushed in deep.  They don't image well if they are not firmly seated in the ear canal.  The bass is totally lackluster until you really get them in there.  Once in place, the sound is just terrific, but know that it can take some effort.  
 
Though the shells are constructed well, the cables look like they might not withstand much abuse.
 
My closest earbud by comparison is the Sennheiser IE6.  The RE's surpass the IE6 in almost every area save midrange.  The RE's have a deeper bottom end, better tonal balance, and allow more transient detail than the IE6.
 
There is a slight mid range spike which isn't apparent until you put them up against other headphones, but if I dial the mids down a bit with EQ, the issue is quickly resolved.
 
Put up against the Beats Tour (which I genuinely enjoy) the bass is much looser and more prominent on the Beats, as you might expect, and the RE's best the Beats fall at the upper end too.  The bess is tight on the RE's but not diminished at all.  However the Beats Tour are much more comfortable to wear, and you don't have to shove them in very far to get optimum sound.  
 
HiFiMAN delivers these in a nifty box, with a bunch of extras.
 
I'll be hanging onto these-- and unloading my Sennheiser IE6's (another pair which have to be jammed in to work).  At a cost nearly identical to the IE6, the RE-272 is a better sounding headphone and a better deal.
 
 

I purchased this-- because for around $150 bucks-- how could I pass?  
 
My needs were to provide a way to get audio out of my work computer and drive larger headphones, while stopping my chair from rolling over the headphone cables.  My computer is set on the floor-- and running a headphone cable out of the computer proved hazardous to the cables.  
 
I'm driving a bunch of different headphones-- Grado 225, UERMs, ATH-50s-- for the purposes of this analysis-- I used the UERMs.
 
Okay- the good-- SPDIF, Optical, line, you name it-- you can source it as an input on the Fiio E17.  
 
The E17 easily drives all the above models of headphones.  
 
Sound is decent.  An improvement over any sound card to be sure.  But compared with the Pico Slim, the bass isn't as tight-- the Pico has a great controlled slam, and the transients are not as evident on the E17.  The E17 lacks the airy quality and overall warmth of the Pico Slim-- which is a rich sounding amp.  Of course the Pico is a one-trick pony-- and costs twice as much.  
 
The digital volume is a bit of a downer, but contrary to some-- I like the input control.  The menus are fairly straightforward-- and I can navigate with ease.  It's a clean design.
 
For $150 dollars-- there's not much to complain about.  This is a great do-it-all box, and I use it more than the Pico because it solves more problems with it's USB input and Ginsu-like compatibility.  On pure sound, however-- there's better out there.
 
 
 
 
 
 

I wanted a closed set of cans for work-- and I like to show off new headgear every so often because I live in headphones at work.  The flashy white pair of ATH-M50s fit the bill.  Take that Beat lovers!
 
First impressions when plugging them into my WA6 was -- "Are you certain they're not Beats-- relabeled?"  Wow the bass thumps!  Fun.  I was also pleasantly surprised by the amount of detail and clarity through the upper frequencies.
 
Not a very open sound-- The HD800 is wide and airy-- these are definitely about a closed in, personal experience.  This isn't a knock-- I like headphones with a point of view-- and these ATs favor a direct approach-- deliver the music.  
 
They're supremely efficient.  Not much power needed here.  They can easily be driven by an iPod, iPhone or any player, though amplification improves the sound, without question. 
 
They are a snug fit-- and barely qualify as an "over ear".  Again-- this is a part of that personal delivery of sound.  You are aware they are on your head-- it's a snug fit, but not overly clamped.  Decent sound isolation-- they should-- given that they are closed.  Pleather covers mean sweaty ears, but they are comfortable.
 
Negatives-- way too much midrange.  A quick trip to EQ window on iTunes fixed that, but they are mid-rangy out of the box.  It's a metallic mid range that without correction would wear on my ears.  There's not much in the way of detail and transients that the higher end headphones deliver.  They don't kill the reverb, but it's not that open feeling you get with higher end models.  While the bass thumps-- the deep deep bass trails off.  
 
The cable is coiled-- It's like a trip back to the '70s.  I scratched my head over that one.  But they do build both 1/4 and 1/8 jacks into the non-detachable cable.  
 
I'm going to hang on to these for a while-- they're fun, they thump nicely.  If I were a DJ, I'd think these were pretty much an ideal pair.  Not going to break the bank-- I can afford to break them-- and they sound nice.  The ATH-M50s are a forward, fast sounding set of cans.  
 
Comparison:  Jumping between the B&W P5 and the M50s-- immediately-- The 50's deliver much more bass-- the P5 is even more mid-rangy- but the mid range is much smoother than the 50s.  More upper end detail on the P5-- and the P5 wins on transients, but the M50s provide a better overall upper end experience-- it feels more balanced.  The P5 is more sensitive to adjustments on your ear.  A slight move changes the entire sonic signature.  The lack of bass and sub bass on the P5 and the over mid-range put the 50's much higher on my sonic scale over the P5 and the construction is better.  The P5 wins on comfort and looks.  If given the choice-- I'd take the ATH-M50 -- if given the choice at gunpoint.
 
 
 
 
 
 

I got my pairs (plural) because my last pair of tried and trusty EC-4s bit the dust.. losing the left channel as they tend to do over 3 or 4 years.  In the past, I'd send $100 dollars and the EC-4s to Shure, who'd fix them and send them back.  Good to go.
 
Unfortunately, Shure has end-of-lifed the EC-4s.  Boo!  So rather than fixing them, they replaced them with two brand new pairs of SE425's-- right off the store shelves.  Impressive that Shure backs their gear as well as they do, it says a lot about the company's integrity.  
 
So now I'm left with two brand-new pair of SE425's.  They are VERY different from the EC-4s, and not in a good way.
 
But let's not go all negative-- the new cable design is terrific.  I like that the cables now break away at the earbud.  Hopefully this will eliminate the left channel issue of the EC-4s (losing contact after a few years due to stress on the cable).  The shape is cleaner and more attractive, but this leads to a huge problem in fit, which is where these headphones fall apart.
 
I started by trying the foam earpieces that come attached to the earbuds.  They didn't get in far enough and the bass was missing-- so I switched to the rubber-- same issue-- the sound was tinny.  Went for the yellow foam-- this was what I used on the EC-4s.  Nope-- no luck.  So I read the head-fi reviews here and someone suggested the white triple tips as the only tip that worked for them-- and that is true-- the second I put the white-triple tips in-- the sound was there.  
 
Full, rich, detailed sound, just like the old EC-4s.  The problem is that the white triple tips are about an inch long and give the feeling like you're being ear-raped.  Yes-- ear rape!  Like-- is this thing going to hit my ear drum?  It's not- but it's a totally uncomfortable situation.   Shure will put Q-Tips out of business!  I can't imagine wearing these for any long-term listening.
 
Sound isolation?  Hell yes-- with this much rubber in your ear-- how can you not get great isolation?  Jeech.  
 
Like the EC-4's there's very good mid-range (maybe a bit too much)-- natural articulate bass-- and slightly rolled off upper frequencies-- no sibilance.  The sound isn't bright, but complete.  Great soundstage.  Wide-- nice for an in-ear.  
 
But if you're buying a $300 dollar pair of buds-- get a pair that won't rape your ears.  Seriously.
 
 

I was on the road last week and wanted a mid to low priced headphones for working out and quick listening.  I own many in-ear headphones now, and after reading review after review how Beats by Dr. Dre where over-priced hyped headphones, I thought I'd check them out for myself.  
 
What I was expecting was a muddy pair of headphones with tons and tons of bass suited for hip-hop.  And that's what they are, sort of.  
 
Beats have so much bass it blows your mind out of the box.  I tend to shy away from bass heavy headphones, so these were a bit of a treat for my ears.  They THUMP.  Forget about nuance, you won't find it here.  My main headphones are Ultimate Ears IERM's.  And they handle bass in a realistic and natural way-- the bass supports the music without dominating the music.  So hearing this much bass is a system shocker.  
 
But what the iBeats get right is the don't obliterate the high frequencies at the expense of all this bass.  If you took a graphic equalizer and created a massive V with the settings, this is what you get with these.  
 
What does suffer are the mids.  They get buried in the mix.  
 
The headphones give a 70's FM hi-fi sound.  They're clean, quiet, tons of bass, decent upper frequency response (though not as pronounced as the bass), and muted mids.  
 
Soundstage is decent, but not wide.  Open ear headphone people won't be jumping for joy.  They bring a decidedly closed sound.  "Natural" isn't in this headphone's vocabulary, they sound processed.  
 
But that processed sound has a distinct advantage-- low level listening.  It's like the loudness button is built in.  They shine at low volumes, and are worth it for this "feature".  Late at night, some cool jazz-- these will hook you up.  
 
They are comfortable, though a bit heavy.  I don't think I'll be pawing at them, they fit similar to the old Shure EC4's extending in and supported by the rubber earpiece entirely.  
 
Looks wise, they're kinda trendy, as you might expect, but they really need to give a bit more cable length.  Great for working out with an iPod or iPhone (they have a mic and control button built in).  The cable won't get in the way.
 
So don't dismiss the iBeats, they have a purpose, and they're definitely NOT junk.  Is there better sound available for the money?  Sure.  But they are enjoyable in the right environment.  Pull out your Steely Dan FLAC files and give them a spin at a quiet volume.  It's a nice experience.
 
UPDATE: A few months in and I have really grown to like the Beats Tour.  I mentioned they fit similar to my old Shure E4c's.  This is a good thing.  This means they're unobtrusive with fancy over ear clips or wires the drag over my ears and annoy me.  
 
The sound has seemingly mellowed a bit with break in.  Another good thing.  I find these an enjoyable backup to my UERMs.  When my ears need a break-- they're fantastic.  I also enjoy the cable.  The short run means they work well with an iPod or iPhone.  
 
Another great use is movie watching.  The extended bass is terrific for a Batman or other action movie.  
 
Needless to say I'm in "like" with these earbuds, and I would again give them a hearty recommendation.
 
They're kinda snazzy, too.  And the volume rocker/microphone works well. 
 
One final final note.  Beware when purchasing that you buy from a reputable dealer.  There are fake versions on the market (especially eBay) that look nearly identical to the real version-- right down to the box and packaging-- but they sound absolutely dreadful.  

I'm a relative newbie to the headphone game.
 
My reference system (at the time of writing) is a Burson 160D, and having a good reference is essential when you're comparing tubes.  
 
My reference headphone (at the time of writing) is the Sennheiser HD 650, which are known for their veil until you put great amplification with them.  I also own UERMs, which aren't appropriate for this type of listening analysis. 
 
First out of the box I was quite unimpressed.  The soundstage was decent, but not exactly impressive.  The bass was muddy and shallow.  More disturbing, is what happened to passages with a lot of reverb.  The decay would clamp down hard, and you'd lose a lot of transients.  I found myself running back to the Burson, wondering what I was thinking dropping $550 bucks on an experiment.  
 

 
The photos on the web site of the Princess Sophia tube had me drooling, and I ordered soon.  The upgrade piqued my interest as the WA6 began performing.  It wasn't audio nirvana, but the soundstage improved and the bass opened up a bit.  The Woo WA6 wasn't winning, but at least it was in the game.  My trips back to the Burson were suddenly less frequent.
 
Reading another review here on Head-Fi, I read a lot of praise for a stubby, unattractive tube called the GZ34 made by Mullard.  It appears the older you go, the better the sound becomes, so says the pricing and reviews on these short tubes.  I found one on eBay for $120.  A 1958, standard base NOS, and the WA6 was suddenly a force to be reckoned with.  
 
The GZ34 launched the WA6 into orbit.  I've yet to find a tube that can compete-- but if you're looking for a cheaper substitute, check out the CV593.  They're lacking a little on the bottom, but match the GZ34 in most respects, and it's a much prettier tube, to boot.
 
UPDATE:  I've located a 1957 metal base GZ34-- and indeed the sound did improve a bit (not earth-shattering-- but a bit better bottom end and openness.)  I've also received a tip that the Western Electric 422a 274B, if you can find one, is a step ahead of the GZ34.  I haven't tested or found one yet that was affordable.  I've also been auditioning a Telefunken GZ32 rectifier-- and have been quite pleased with its overall presentation.  It is worth noting that all of these tubes mentioned are a quantum leap in sound ahead of the Sophia Princess or stock 5AR4 tubes.
 
On the drive side, tube after tube after tube sent me back to the stock RCA 6DE7.  I still haven't found any worthy upgrade, though I'm currently testing a 6SN7 that's showing some promise.  Woo claims the 6GL7 is the premiere tube for power on the unit, I couldn't disagree more, and I was sorry I flushed the $110 down the drain.  While adding more drive, the GL7s added some distortion and crunch, and reminded me of an FM radio sound circa 1977.  The lesson here is the rectifier tube makes a greater impact on the tonal quality than the drivers, so put your money in a good rectifier and be happy with the stock 6DE7s.
 
UPDATE: When I moved from the HD650 to the HD800-- here's where the power tubes came into play.  The 6DE7 was no longer enough to drive the power hungry HD800.  The GL7 still lacked a bit in clarity for my taste-- so I tried the legendary 6SN7 tubes-- and the pairing is now quite impressive.
 
For intense listening, the WA6 now outperforms the Burson 160D.  That's saying a lot.  However I've spent hundreds and hundreds in tubes to get here.  The Burson excels at everything and gives you a DAC converter and pre-amp to boot.  It's a better buy. 
 
If you like tweaking and hunting-- the WA6 can provide that rare audio nirvana we seek.  But it's going to cost you and be prepared to roll through a lot of tubes before you find that ideal match.  
 
A final word on fit and finish-- this unit is just beautiful to look at and built like a tank.  
 
FINAL UPDATE: Eventually I was using the Burson 160D so little for actual amplification-- I sold it and moved to the Wyred4Sound DAC2.  The amp stage on the Burson was simply no match for the Woo with upgraded tubes.  I sold the WA6 in the fall of 2012 after a WA5LE (yes, I'm officially a Woo addict) came available on eBay for a huge discount.  I couldn't pass on the deal.  What the WA5LE revealed is that the WA6 doesn't have a lot of power to drive demanding headphones.  While the WA6 drove the HD800 fine with the upgraded driver, it didn't have enough power to really open up the HD800 to their full potential.  This is not to say the WA6 isn't a good amp, it's a terrific amp.  But know that by moving up in the Woo line, you do get better sound (deeper bass, better soundstage, etc).  If you're spending more on a pair of high-end cans-- you have to plan on spending more on an amp to bring the most out of your expensive purchase.
 
 
 
 
 
 
 

Having spent time with a lot of Bose QuietComfort (X) headphones on my ears, they all left me wanting better sound.  I work in a noisy newsroom.  The need for cutting back some of the chatter is always a premium here.  Active cancellation was the first stop on the path that led me to in-ear customs.
 
Style File:  The Sennies are pretty attractive, as far as headphones go.  Nice mesh case, and the cups are rather large (appreciated all the more after spending time with Bose). Sennheiser did a great job on comfort.  You can wear these a long time without fatigue.  If the thinking is-- gotta be comfy through an 8-hour flight, then mission accomplished.
 
Cancellation:  Well this is the big headline, and the reason most will be buying them.  If you're all about cancellation, spend the extra cash for good customs.  They do a better job at passive cancellations than the actives ever will.  I can still hear a lot of the world around me in active monitors, though it is muted.  Simple on-off comparisons confirm the headphones do their job, and to my ear, produce an overall quieter effect than the Bose.   
 
Sorry to report, the sound quality out of the 450s is only average.  Decent but not extended bass, stronger through the mids and a precipitous falloff on the high end.  There's very little soundstage to be impressed by. I own little to compare them with, and will amend once my 650's arrive.  I'm expecting this pair to pretty much take it on the chin.  They don't sound 'bad' per se, but they don't 'wow' in any area, either.  I get more of a lift out of my Bowers & Wilkins P5's, which at least show some character and can provide entertainment much as a comfy old pair of slippers will on a cold night.  
 
My use for this pair are as a relief pitcher at work, if I need a break from my in-ears.  They serve that need, but they are definitely not the first pair of cans I reach for.
 
Final Thoughts: If you're a slave to active technology, these are as good as it gets.  The only other pair that did cancellation this well were my old Sony in-ear buds, but the Sennies blow the Sonys away in sound quality.  If I were looking for the best active canceling cans, I'd say look no further.  But you can find better sound for the money.
 

These are my go-to headphones when I don't want to use my customs.  They are easy to wear, sport all-day comfort, provide reasonable isolation-- to excellent if you buy the foam inserts, and are a full-range in-ear monitor lacking very little, and a steal for the price.  I own 3 pairs.
 
I keep a pair of these in my bag at all times.  They come in a round zippered case that's quite protective and unzip in a second.  If I need to grab a quick listen to something, these never let me down.  
 
Construction is good, but about every two or three years I have to send a pair back for refurbishing from Shure.  The wires are a bit thin, but they have never separated like my e5's.  
 
Balance is the word that best describes this set of headphones.  They have excellent clarity, a reasonable soundstage, and decent bass extension (though not necessarily impressive).  
 
In baseball terms-- these are like lead off hitters.  They consistently get on base and score runs, but they're never going to knock anything out of the park.  They do their job, do it very well, and get on with their business.  They're extremely comfortable.  You hardly realize you're wearing them, meaning you can have them in literally all day and never fatigue.  
 
There are better sounding earbuds out there, no question.  I have a full range of Shure buds at my disposal, but these are the one's I most reach for, and I feel are essential to my kit.  
 
They do everything well, and can be found for under $200 dollars at times.  I have fancier rigs, but for everyday listening and getting work done-- you can't beat them.

What can I say-- they do their job-- which is to protect my other headphones from use when I need to work out.  They do their job well, but let's face it--  they don't sound very good.  
 
 

I've recently amended this review, based on my education into the world of Head-Fi.
 
I've been toying around with getting a set of in-ear customs for a long time.  I caught the write-ups in my audio rags about UE's new product and jumped all over them.
 
I'm a video editor, but I also do a lot of music and mixing, writing, directing, and anything else that has to do with entertainment production.  It's like UE decided to custom build a pair of in-ear headphones just for me.  Thanks guys, much appreciated.
 
My super-secret hope?  They'd make for pretty good listening, too. 
 
I don't have any experience with IE custom monitors prior to this.  I've had about every model of universal buds Shure ever made-- and my favorite pair prior were the e4Cs.  I had the e5's but they hurt the ear after an hour or so.  The I owned one pair of UE's in the past, and was disappointed in their construction.  They were pretty much toast within a year-- but they were low-grade consumer models.
 
No worries with the UERM's.  These things are built well.  I opted for translucent black.  Something about clear and in-ear made me think of gross ear wax I never wanted to face.  The black is pretty striking.  I also did double Capitol logos on the ears.   
 
The customs take some getting used to.  Mine hurt at first.  After a week things chilled out.  There was a time I considered taking them back for a re-fit, but I stuck it out.   
 
Sound quality-- well that's what these are all about- and they do sound fantastic.  I would call the soundstage very good-- but not up to the level of a quality over-ear open headphone.  Brilliant highs.  That's where these really shine.  I notice transients-- particularly in passages with great natural reverb.  Open and extended.  
 
The one common criticism I ran into about this model was the lack of bass.  They certainly can't stand up to the LCDs or HD-650 or HD-800.  And they don't go as deep as Dr. Dre Beats.  But where Beats have a thumping quality suited for pop music, the bass overpowers on everything else.  The IERMs bass is extremely tight.  What they lack in deep low end they make up with in bass detail.  A little EQ will bring the lows in, but the detail in the bass is where these shine. You can sort of hear the skins on the drums stretching and retreating.  You can hear the fingers slip across the bass strings.  They're just ridiculously accurate-- almost comically so.  But in reference listening you don't want that deep extension there when you're trying to figure out what you're listening to.  
 
You might get the sense that I like these by now...  Indeed.
 
I knock the design a bit, because-- let's face it-- there's nothing sexy about the shape of your ear canal.  But the box they come in is smashing-- and has my name printed on it-- but the buds have a hard time fitting inside, so I bought a Pelican case.  It's waterproof anyway-- a good way to protect my thousand dollar investment.  
 
My and my UE's are going to be married for a long time.  
 
 
 
 

I bought these at an Apple store after jumping around between a few display models, and they certainly were the best of the lot that they had, in both sound quality and comfort.  I didn't want to take them off, so that told me something.
 
What's wrong with them-- Well the mids can get mucky-- like there's a film over them.  The bass is loose on the extreme low end-- it gets really slappy in the extreme lows below 200hz.  The treble gives me the most bother.  There's a real lack of imaging in these phones-- they bowl over the transients and there's little soundstage anywhere.  Compared to my UE Reference Monitors, well, there isn't really a comparison.  The UE's do everything so right, it's laughable when I jump to the B & W's.
 
So you'd think I'd be chucking these in a drawer and never look back, but a funny thing-- despite their shortcomings (I tend to address them with EQ- and if you want a different appreciation for them fire up iTunes and put the "electronic" eq on them and dial them in a bit) these headphones are like a comfy pair of old slippers.  They don't do anything particularly well, but I find myself reaching for them often because they're so darned comfortable to wear.  I can take a snooze while wearing them and they're wonderful. Beware- in warm weather, your ears will sweat!  
 
One final note-- because of their flat profile, there are about five positions they can rest on your ear, and each sounds entirely different.  Play around with placement before dismissing them, you might find a really good position and spend the next two months trying to figure out where you had them on that great night of listening they provided way back when.  
 
Yeah, they're quirky and expensive, but they look good and feel great.  I'm not getting rid of them, they're a creature comfort my ears appreciate on the right occasion.  They're not for detailed listening.  They're for curling up with a good book on a cold night.  Soul food for your ears.