The MDR-MA300 changes somewhat after about 10+ hours of burn-in. However, the source/synergy also matters greatly. It seems like the engineers at Sony tuned these guys to play with more neutral sounding sources vs. the "brighter" Sony house sound.
My initial reaction is at the end of this post.
My current impressions:
Bass: Still boomy, farty, uncontrolled and sloppy. Even more so with Sony gears than non Sony gears. Odd that. I think the mid-bass range is heavily affected here. In fact, I had to floor the bass bands on the Walkman to get to a point where I'm not bothered by their flabbiness. It's still here and present after about 10+ odd hours. I'm not sure if additional burn in will have effect positively or negatively.
That said, when I paired these with the Sansa Clip Zip (Rockboxed) and the iPad 2, the bass (mid-bass) was tamed a bit, noticeably. I considered the Walkman's output to be a bit on the bright side. Well, they still are. Just to be sure, I checked against MZ-NH1 (old HiMD player). And yea, severe mid-bass bloat. It seems as though my other phones are tuned for Sony gears (a lot of the headphones I have plays well actually) and these for other gears. So... yea, severe mid-bass hump makes these quite bloaty.
If nothing else, source matter with these cans (synergy over burn-in I'd wager).
Mids: No appreciable improvements after 10 odd hours. Still somewhat recessed and veiled.
Trebles: Sibilance is more or less gone. The veil is somewhat lifted, but I still think the upper range takes a dive around 18-19kHz? I can't verify this however, without measuring equipment... which I lack. So...
Soundstage: Opened up a bit, but is still unimpressive when compared to the slightly more expensive cans ($70 range. Sony signature store here in So Cal sells the MDR-SA1000 for $75 with tax. I would take those in a heartbeat over the MA300s).
Generally, my collection of open-ended cans have leaner, tighter, and well controlled bass that do not overwhelm (Modded HD555, SR60 + G-Cush, MDR-SA1000, Pioneer SE-A1000). I think the overemphasis on the midbass of the MA300s makes it questionable. Oi. I have no clue if Sony had planned on making a mid-range to complement the MA700s. But right now, as it stands, the MA300s, whatever merits they have, gets squashed by the mid-bass bloat.
This, however, makes for a killer set of cans to watch movies and TV shows with. Especially action type with lots of booms and kablooies.
Unitaskers? Perhaps. Here we go with another 10 odd hours to see if there are additional changes.
They are, however, very, Very, comfy. So, there is that.
Just got these from the local Sony Store (not their flagship store at Culver City, go figure that one out). Not a review, just impressions at this point.
These are about an hour or two into its burn in phase. Keep in mind that, however, that I'm not a big burn-in proponent/believer. This is un-equalized output from a Sony Walkman, NWZ-E465.
These are open air/open back design. The drivers are on hinges, so they will move back to match angles with your earlobes. Unless your ears are super huge, it should fit in the cup. Cup material is lined with a little rough cotton materials with foam covering the drivers proper. It's softer than the materials that's used to cover the MDR-SA1000/3000 but not as soft as say the HD595. Like cheaper lower-end Sony's they use dual cord entry. The top of the headband lacks any padding. Disappointing and adds to a bit of discomfort in what is a pretty comfy and cool headphones. With any good set of open air cans, there is zero isolation in or out.
Housing is huge. I mean HEUG. It's good 3 to 4 inches thick.
The driver housing is in an open back. I'm not sure if I will want to classify this as an full open cans though. The driver housing outside of the ears is covered/closed. So, the drivers are not fully open. It's better to consider these as semi-open, I suppose. I'll have pictures up here for you to decide shortly.
Soundstage so far is somewhat disappointing. It's more along the lines of 2D, flat, and doesn't extend outside of the cans, though I'm at this point inclined to blame my tracks than the cans... I need more materials that exploits soundstaging to see if I'm just over-reacting. (My Walkman currently lacks the tracks that I test headphones with, so...)
It has quite a deep bass profile. For an open ended cans, the bass extends quite a bit way deep. Like Subwoofer deep. Not controlled mind you, but flabby, wet, farty bass. "Why so Serious" from Dark Knight soundtrack has a deep bass only movement around 3:30. The headphone does handle the bass in that it actually can play the portion. However, it adds an artifact (an audible tick) where there shouldn't be (I've listened to this track quite a bit on other phones and sources). Perfect for watching movies, as I'm watching The Dark Knight and it fits perfectly.
Aside from one bit of brief, passing sibilance, I've not noticed any obvious. Mids seems to be a bit recessed, but as I said, I don't have my reference tracks on my Walkman to say this one way or another. Female vocals seems to touch off sibilance a bit more. Dido's vocals seems to have a bit more edge to it than she normally does.
There seems to be a veil over the high end of the cans. Again, these are about 3-4 hours old at this point so I've no clue if this will change as it gets broken in. Sibilance as well. Seems to take EQ quite well for now.
I have to say that the MA300 is somewhat middling in its performance. I don't know if I want to keep these. These are good entry Open Air cans. But anything from Grado would smoke these. Likewise, the HD5xx line from Sennheiser or Sony's MDR-SAxxxx line offer better performance. The latter now can be had as low as $70 at their flagship store, and right now, is money better spent than MA300.
I know there was a theory floating around that Sony just took the XB drivers and slapped them in open housing. AT this point, I'm inclined to agree. Lazy move if it's true.