Cable: 1.2 meter 3.5 mm straight plug & 3 meter 6.3 mm straight plug
Sensitivity: 115 db
Response Range: 10-28,000 Hz
Weight: Approximately 334 grams
I purchased these when they first came out during Black Friday in 2016, when they were on sale for $100 CAD. Until these I had mostly spent all of my money on IEMs since they're a lot more discrete to wear outside and I'm on the go a lot. I got the 598 CS because I wanted something more comfortable for when I'm sitting at my desk at home. At the price I paid for them and for what I need them for, I think they were a great purchase and I'm very happy with them.
Design and Build Quality
Out of the box, the 598 CS come with just the cables, and the headphones themselves. You get a 3m 6.3 mm jack, and a 1.2m 3.2 mm jack with a one button remote and mic. They do not come with a case nor do they fold at all. The body is all plastic but it doesn't feel cheap. The whole thing looks solidly built, nothing seems like it's about to break and nothing moves in ways it wasn't intended to. I'm personally not a big fan of how they look but given that I only use them at home, it doesn't matter. The cables are my one big complaint. While, its nice that the cable comes with the a remote, it's still far from great. The remote itself is fine, but I've had these for a couple months now and the cable is still hasn't fully straightened out so I doubt it ever will. It's just a regular rubber coated wire and has a straight jack at the end.
Headphones - 8/10
Comfort with these is amazing. They feel fairly light and I have no problem wearing them for the whole day. The ear pads are made of a weird material that seems like a cross between velvet and leather and have what feels like memory foam on the inside. I'm not sure what either of the materials are exactly but they feel amazing. They feel firm on your head but not in a constricting way. They don't make me sweat even after hours of use. The ear cups the selves easily fit my whole ear, nothing else to really say about this. The headband is synthetic leather on top and bottom, and has nice padding. Not much to say about this either, it's just good. They're feel fairly light and have solid clamp. They feel very secure on my head while not compromising on comfort.
Sound isolation is not that great, with no music playing I can still hear even just the hum of my computer next to me. As expected, they also leak a fair bit of sound. Even at 50% on my google Pixel, someone sitting next to me in a quiet room would be able to hear them. Given that they're closed back I expected a lot better. It sounds like a lot of it leaks through the back plates so even if you changed the pads I'm not sure how much it would help.
Really easy to power, I usually listen to them through a Fiio e10k but my I can reach a comfortably loud level at around 75% on my Google Pixel.
Highs - (7.5/10) - The highs are solid. They're nice and detailed, but sometimes sound a tiny bit too far back. They usually didn’t blow me away, but were also never disappointing. No big complaints but also not much to praise.
Mid - (9/10)- Mids are rich and warm sounding. I've been blown away by the amount of detail in certain songs that these provided. Male vocals sound especially warm and lifelike.
Lows - (7/10) - Bass can feel disconnected from the rest of the song sometimes. It's still very detailed and rich but it doesn't jump out at you. It's not bad necessarily. Percussion sounds very nice and punchy. If you're looking to hear skull shattering bass in every song these won't give you that. For me personally, I still found bass heavy genres like EDM sounded really good and it was more so things like classical music with more nuanced/atmospheric bass in which it felt lacking sometimes.
Sound Stage - (8/10) - Sound stage was a lot better than I expect, it's really nice for closed headphones. I was thoroughly impressed. Imaging could’ve been better, only distinct let, right and center.
Separation - (7.5/10) - Separation is really clean. Vocals stick out exceptionally well. Even in fairly busy orchestral music I could make everything out nicely.
Overall - For the price, the combination of great highs and mids, with a clear low end and exceptional sound stage and separation provide a great experience for the price. That being said they don’t do anything overly exciting or interesting, just a good quality, fairly neutral, generic sound.
It's kind of weird how they're closed headphones, but at the same time have very little portability and pretty satisfactory sound isolation. That being said, for my home use where there's other people constantly doing their own things these work great. I can't hear anyone, and it doesn't matter if there's sound leaking. If you're using these in a busy home but still want to keep to yourself, these are a great pick for the price. When I got them they were on sale for 100 CAD, at this price, I think they're a great purchase. Regularly they cost 150 CAD which is the same as ATH-M40x. I've personally never tried the ATH-M40x but I have heard a lot of good things about them so you'd need to do more research, but either way these won't disappoint.
EDIT: Added a bit more depth to sound review and added a specs chart.
Pros: Effective Noise Isolation, Nice Sound stage, Great Lows and Highs, Nominal Impedance of only 23 ohms, Very comfortable, built quality is also good.
Cons: Bass could have been punchier...
Sennheiser has launched an excellent closed back over ear headphone which has the premium sound of the legendary hd 5 series but instead of the traditional open back design this has a closed back nature but has got a sound stage which deserves to be appreciated despite its a closed back headphone. Unlike its other siblings, this can powered by any device to get good quality sound due to its lower impedance of only 23 ohms.Comes with inline remote mic facility with play/pause feature that works effectively on almost every smartphone. These headphones boast of very nice instrument separation and clarity especially the Vocals on these are very pleasant to hear as the mids are a bit forward. highs are nice and not piercingly high and also the bass is deep but could have been punchier. Mids are okay(dont except them to be clear like an open back headphone), but the highs are lows are much more noticable and this headphone has a overall warmer sound signature.No issues regarding sound leakage.A dedicated amp will increase the bass, clarity and overall sound quality but it works fine with ur phone so there is no urgent need for an amp.This is a good treat to a lot of people who has always expected the senn's to sound louder and these do it nicely without no distortion at full volumes. Also the build quality is good, can't demand for more at this price.