OK, I've written this primarily for other forums, but feel like i may as well share it here as well....
The new Sennheiser CX300 ear buds are Sennheisers answer to a market that has long been dominated by the likes of Sony's MDR-EX71 and various rivals, like the JVC HA-FX55.
To me, a lot of these earbuds offered reasonable if not particularly great sound quality, often suffering from a recessed midrange and mainly being good if you use older ipods with their well known bass deficiency problems.
There are also the more upmarket phones, like the Shure E2C and Etymotic ER6i etc... and then you can get even higher end ones, however, that would be missing the point...
Previously to this, I have used Shure E2C, JVC HA-FX55 and Sony MDR-EX71.
The CX300 cost me £32 from discount discs, so that puts them just £2 above the EX71.
Trust me when I say, these are worth it. In fact, they absolutely destroy the Sony's, and JVC's. Compared to the Senn's, the Sony and JVC have undefined bass, and no midrange to speak of, and harsh treble, and generally sound unrefined.
Compared to the Shure, well I think these beat the Shure's as well, it makes those sound a bit muffled and midrange recessed as well. The only area the Shure's beat them to my ears is isolation, where because of their design, the Shures attenuate a bit better than the Sennheisers.
From what I have heard of these, you may well have to spend £100 just to match the overall sound quality of these when it comes to earbuds.
In fact, it comes fairly usefully close to my full sized Beyerdynamic DT531 headphones: OK, so they arent as good as those, but the Beyers are full size - so they should be better. The Beyers are more comfortable, and are better in every sonic area, but not MASSIVELY, just noticably. You would never pick the Sennheisers over the Beyers, but you would NEVER wear the Beyers in public, unless you didnt care about looking like a total prat, and didnt mind carrying a pocket amplifier to go with your ipod!
In short, if you are looking for a reasonable pair of portable headphones, you should put these at the top of your list, and frankly, not even bother with any alternative that may cost much less than £100, IMHO
Hi Paul & thanks for your comments. How do they compare to the Koss KSC- 75's regarding sound detail? (Saw you recommending them to someone on another post so I presumed you had a pair) I have a pair of the Koss 75's and absolutely love 'em. Fantastic sounstage and instrument seperation. They just leak a bit of sound, that's all. After all the hype, I decided to order a set of Senn CX300's from 
I'm just asking for a quick comparison between the two, seeing as this guy's got both pairs. It didn't need a few days running in for me to say the Koss 75's were a fantastic earphone. They hit me immediatly. I'm sure he's intelligent enough to give me a description of how they sound now and maybe later after they've been burned in a little... Chill Out.
Just asking for your opinions on CX300's that's all 
... not a big deal.
Big Tony...Sorry mate, I thought you were wittering and lecturing me about the phones being reviewed too early (ie. before they've had a chance to burn in ) I apologise if you meant otherwise 
I've ordered a pair of the CX300's in silver. I also own the Creative 630,s which look very similar. I was very disappointed with those though. I thought the sound was crap. Hoping these have different drivers and a better sound.
.
Linear Mode
