has anyone compared SD-2/SD-3 to Sony MDR7550/1000? Is there a big gap between these iems?
I have SD 2 and MDR 7550. Here is my take:
High: SD 2 sounds a tiny bit brighter. 7550 has a bit of a grain to the sound compared to SD 2 and is slightly more siblant (I am very sensitive to siblance)
Mid: They sound very similar, but the vocals on SD 2 sound a little more intimate.
Low: SD 2 definitely has more bass impact and quantity. However, due to the dynamic driver, 7550 sounds more natural and a little better decay.
Soundstage: 7550 has much wider soundstage, but the depth is about the same and SD 2 has better center focus.
Background: This depends on the source, but from my experience SD 2 is a little harder to drive/has more background noise than 7550 due to multiple balanced armature drivers. Straight out of Samsung Galaxy S3 or Sony Walkman F806, SD 2 has substantially more hiss. Amp will solve this issue.
Personally, I find $100-200 difference between SD 2 and MDR 7550 to be a pretty big difference. I loved my 7550 before buying SD 2, but after buying the SD 2 I have never listened to 7550 again. 7550 still has it's own advantages over SD 2 with its natural bass and wide open soundstage, but SD 2 overall sounds more refined and elegant to me. I listen to vocals 70% of the time, and though 7550 excel in that regard, SD 2 does it even better. Due to the bass quantity, SD 2 also has an edge in terms of modern genres such as pop, dubstep, electronic, etc. I also prefer SD 2 over 7550 when listening to jazz or classical music, but some might prefer 7550 in terms classical music due to its soundstage.
Hope this helped.