Just a heads up, my previous headphone was FA-003 and it really serves its purpose well and is definitely the best bang for buck. In fact, I had been taking a great amount of notice about this HD600 vs HD650 debate for a very long time now but decided to go for FA-003 previously for lacking the bucks to buy one of this. One thing I dislike about FA-003 is that wearing it to listen for music for a long period always makes my head feel uncomfortable (even after adjusting the head band in various level), particularly the clamping force that I had. The listening experience is good, but the comfort always prevent me from really enjoying music for a long time.
Now this review is coming from a non-seasoned audiophile and never watched any unboxing video of this product before. I just read tons of written reviews about them. I'm not a professional reviewer of any kind so please bear with me if I spoke something that might sounds funny to you. What is written below is what I have thought in my mind right now.
Here goes the quick review:
When unboxing it from the outer jacket, I'm instantly amazed on how well Sennheiser designed their box. Kind of like a jewelry luxury like box you might say, which I think it should be given this hefty price tag :) Further opening the jewelry box reveals a 'white instruction manual', with the headphone in its great luxury just behind it! Frankly and jokingly speaking, it was the white instruction manual that first grab my attention when opening it (well I suppose because it is white while the rest is black in color)! I thought that it is the last thing that I should see after picking up the HD600. Well normally it should have laid somewhere under the product instead of having it 'in-front' of the spotlight, which is the HD600 itself. I think you might find it amusing as this is the first time that someone actually spoke of something like this :-P
When trying to put on HD600 for the first time, I instantly noticed how comfort it is (after the proper adjustment of the head band of course) and the ear pad is really comfortable. I already wear it for almost an hour now and I am still yet to feel any heat coming from my face. HD600 also give a whole new listening experience due to its open can design. Now don't get me wrong. I still feel that FA-003 gives the almost similar soundstage and sound signature as HD600, but not exactly the same. There is definitely a difference between close can and open can design. But FA-003 really did great even for its closed can design.
Regarding the sound leakage that most people is concerned with open can design, I would say it is of relatively small amount. Well perhaps I am not used to listening to very loud music. With my normal listening level on New Age/Soul music (well how loud can you go when listening to these kind of music. Loudness will definitely have adverse effect whereby these type of genre are supposed to carry a very soothing and relaxing listening experience), I can barely hear the sound leak. Well there is still a small audible sound coming out from it but that is only important if someone is sitting very close right next to you and paying a really close attention to the sound in their surrounding. Otherwise you won't be bothering them much.
Talking about cable, it is very much thinner than the Fischer FA-003 so I guess you need to take deliberate care of it, especially the bending. Some people might find this a cons but I actually prefer a thinner and lighter cable. I always take deliberate care of cable so its not an issue here. I just lay it on top of the table now instead of having it 'hanging' around the floor just as I used to do with my FA-003 cable.
I'm currently connecting this babe to iCAN <--> Fiio E17 and the listening experience is really superb.
Now previously I'm always afraid to purchase any open can design because of the sound leak and no noise isolation. But after trying an open can design, which is the HD600 itself for the first time now, I found it to be very pleasing. In fact, I prefer to hear some external noise so that I can still know who is coming into my room and I can also speak with them without having to remove my headphone. You might have different thought but I guess you just had to try it out for yourself to feel it.
All in all, I must say that this HD600 really worth its price tag. Well it might be a bit pricier but there's always FA-003 as an alternative if you don't mind the slight comfort issue that it had.
P/S: Come to think of it, my most long used earbud is actually from Sennheiser too! The MX-660. Already used it for more than 8 years now and it is still working great!! This only proves that Sennheiser really makes GREAT QUALITY product!!