Of the sound and ear fit is great. What i like best is the easy shift from one source to another. Superior to any other product I've used.

I use these in a live (contemporary) church setting. There is not much clarity at all, and I frequently get lost because I can't hear the bass and drums. As an aux keys player, I need bass and drums in my mix, but I can never hear them. I pretty much rely on the hi hat and rhythm guitar for my rhythm. They are decent ear buds for casual use, but not for a live music setting.

Sound good and fit nice.

Bought two pairs of these and the right ear stopped working in both of them. They were not used more than 5 times each. Disappointing.

I love them

These earphones lack low end and only work if you stuff them into your ears to an uncomfortable depth. As package deal with the U4 they make both products sound cheap. The U4 sounds better with better quality earphones.

I was frustrated by how hard it was to find a really good, durable set of "hook" earbuds for my desktop use -- none of them sounded like real headphones and they only lasted a few years , the way I rode 'em hard. Then I though "hey, what about in-ears buds -- aren't those just stage-grade headphone drivers?" And so yeah, these work perfectly for my needs. They're loud, they're relatively high-fi and they have the right curve for video creation -- not too much bass and any extraneous noise is very conspicuous. They're for very proof-y listening. Maybe not kick-back audiophile, but for audio track troubleshooting they're fantastic.

Being that these are Sennheiser, I expected them to be a lot better than they are. I can't seem to get a good defined mix with them, so I have opted for a different brand. I hope that I can get my money back.

I popped for the Sennheiser earbuds because I thought that lower-priced buds wouldn't give me anything below 75Hz. Well, these sound like a 1970's car AM radio. I use a Boss OC-5 for bass doubling when I play my Martin 6 string. But you can't tell if it's on or off with these. Pitiful. Look elsewhere if you're looking for a full range earbud.

I bought these thinking "Well if they're not that great, I've wasted money before...." and WOW - these are fantastic! Bass response makes you think there has to be a second driver. Thanks Sennheiser and Sweetwater!

I have several Sennheiser products. You can't go wrong with Sennheiser. Their handheld condenser stage mics are amazing.
I bought these in-ear headphones to use with abn XVive wireless in-ear monitor system. I was not disappointed! They are crystal clear and comfortable to wear.

Purchased as part of an IEM package. Excellent quality sound. I can hear every nuance in my voice.

These are simply amazing. I love to put them in and lose myself in the music. The sound is rich. These are way better than the shures at the same price point. Their fit and finish are great. You cant miss we these. Sound as good as some multi driver units in my opinion.
For this price by 2 or 3!

I wanted to get studio monitor ear buds because headphones become so uncomfortable after awhile. I am not at all pleased with these, and they don't even come close to the quality Sennheiser is known for. First of all, believe it or not, their dynamic range isn't as full or as accurate as a cheap pair of Panasonic earbuds I have. Also, there's NO way to keep the left earbud on these from repeatedly falling out of my ear. $ wasted because they're not returnable, which I understand…but I don't appreciate the relatively low quality on these.

I never put a bunch of thought into earbuds, I only used them when mowing or working on something...WELL!, after buying the Xvive wireless in ear system combo with the Sennheiser IE 100 Pro ear buds my under educated arse got a lesson in
" holy crap this sounds awesome!!".
Quite impressed for sure.

The good: They fit well and provide attenuation as advertised. Very comfortable ear loop holds them in place.
The Bad: Frequency response is biased to the high side. With EQ flat there is some bass response but predominantly all I hear is the higher frequencies. And that is across multiple sources. Yes, what a person hears is subjective - the EQ I use to give them an OK sound is Shelf 10KHz - 5db, Shelf 100Hz +3, mids are flat. Works for me.
First time owning IEM's - price point is good. Have no reference to other more expensive IEM's but cant recommend these to future buyers.

I have the Shure SE215s which are a great IEM, but these things in my opinion sound just a little bit nicer. Like any other IEM once you get a good seal the bass thumps with clarity and the highs are crisp and clean. My only complaint and its not really a complaint its more of a preference, I don't like the feel of the cable, it feels flimsy and low quality but I have not had any issues with it yet. With that said, these truly are a great earphone/IEM for the low price. You can't go wrong with these.