Pros: Solidly built, bass oriented, mildly V shaped signature that does not sacrifice the midrange.
Cons: Jack is bulky, may not accomodate all phone cases. Bass over bearing out of the box requiring some burnin to sound it's best, has a midbass hump.
When I received my package I liked the look of the IEM and accessories. It came with a good selection of tips and a very nice semi hard case. The cables looked very durable and strong. The only issue I had was the jack only just fitting my phone cases jack entry port. The cable is flat and nice and supple helping it to lay down flat against the ear when warn over ear. If I had one issue with the IEM design it's the lack of easily identifiable marking for left and right ears. Note this IEM IS MEANT TO BE WORN OVER EAR but can also be warn hanging down at the cost of comfort and microphonics.
Out of the box when I first listened to the IEM I was more than a bit concerned that the bass was over cooked as it was causing me a headache. The mids and treble were both well presented though and I knew I was going to like the warm tilt of the midrange as well as the nice sparkly treble which was nice and clean and not exhibiting much if any sibilance or grain.
I then put these on my computer and left them to cook a mix of music and my burnin files. After 20 hours of this burnin the bass had started to tighten up and not be as over bearing. Another 50hrs and the bass was as tight as I can hear in regards to any further change.
The burned in headphone has a definite bass orientation that has a bit more mid-bass hump that I like but one that many people will really enjoy as my personal taste in sound signature is generally to bass shy for most people. I find the bass to be tight and good for genres that have a driving bass line but a bit lacking in texture for bass oriented instruments like the Cello. This is not to say it is no good for classical genres, it just isn't as resolving as what I like. BUT I haven't found any headphone in the price range of this IEM that is so don't let this dissuade you from looking at this IEM in comparison to like priced IEM's.
The mids of this headphone are less pronounced than the bass and the treble but I never found myself feeling like I was being short changed when listening to any music. The mids have a warm tilt that is very satisfying and clean and they worked very well for male and female voices. I particularly like listening to Dianna Krall and Patricia Barber.
The treble is also well done and sparkly without crossing the line into sibilance or exhibiting any grain. I found cymbals to stand out nicely in pieces where they were an integral part of the music without overwhelming of being overwhelmed. In comparison I also have been reviewing the Brainwavz Delta which had a decided graininess to the treble. So youo see a definite step up in sound quality from the Delta to the S1.
So the over all signature of this headphone is a mild V shape that does not make the mids recessed or distant. The sound stage put you near the front of the stage but not to close allowing for everything to present without sounding cramped or messy. In regards to genres this IEM will be great for bass oriented genres like dubstep and probably trance, I really liked it with Jazz and some classical such as choral or orchestral, it worked with most classic rock and was nice with Celtic and country music. I only encountered the odd song that the mid-bass started to be come more than I could comfortably handle.
In comparison to the new Brainwavz Delta I think the S1 is more technically adept but is also more colored in it's sound. If you want balanced on the cheap the Delta is probably your best bet. But if you want a bass oriented warm sound the S1 will definitely fit the bill. I won't go as far as to say this is the best IEM for it's signature style and price point as I do not listen to a lot of IEM's with this signature but I do think it will at least hold it's own against most IEM's that have a similar signature if not beat many of them.