HAF-X is an awesome case. I use a HAF 932, but would have chosen the HAF-X if it wasn't too tall for my cabinet.
The large 200/230mm fans are very quiet while still moving the air. I thought that I may need a fan controller, but you really don't.
Make sure you get a quiet video card if noise is important; for GTX cards that means a non-reference design with more than one fan.
Don't forget your power supply design either; I went with a super-sized (oversized for what I needed) Corsair AX1200 which can run fully loaded renders without ever needing to speed up its fan. If you have a properly sized power supply, most will need to move above "idle" to keep cool when you get your cpu cores a crankin'.
If you need really quieter still, you will want a case that has noise baffles in the front (a design where you cannot "see" the fan(s)).
I like Fractal Design, type:Define R3 or the bigger Define XL:http://fractal-design.com/?view=start&category=2&prod=
Neet design and very good sound/noise isolation
I have recently gotten out of an antec 1200 case and into coolermaster cosmos S.
now while it is the uglyest case in 7 navies, it is 630mm deep and thats 1 of the requirements I wanted for my last rebuild.
Now all my cables look a little tidy ish.
Thanks very much for the information given. I'm looking forward to getting the new case and expanding my system a little further.
My PSU and graphics card were only replaced a short while ago, so thankfully they'll suffice for now.
I would be interested in hearing from any other Haf X owners on how satisified (or not, as the case maybe) you are with the noise levels whilst editing video.
I have the HAF X and it is everything I wanted. It is quiet with the stock case fans. I use Speedfan to adjust fan speed but even at full speed, the stock fans are quiet and move a lot of air. I take advantage of the removable bay (I only use one) for a backup HD. Only complaint I have is that the case didn't come with stock connectors for the two USB 3.0 on the top front of the case. In reality, I don't have any 3.0 devices so I modified the connectors to plug into an optional set of plugs on my MB. The build quality of the case is the best I've had. I don't need a second fan on the top of the case (it's optional) for cooling but if you want it or need it, it's there and you can get a fan from CM that will work (with some effort I understand). The MB I have needed a case that could handle an oversize MB; this case does that with no problems. I have 5 HD's, and the drive bays are fully occupied. I would need to start using the external drive bays if I needed to add other disks; which I don't anticipate. I don't use or care for external lighting but if you're into that, the front fan has LED's that you can turn on or off. I don't move my case around much but if I did, I would be careful as the wheels don't look like they would take a lot of punishment.
I would recommend this case without reservations as long as it can accommodate your hardware.
That's very helpful indeed. Thank you very much for such a comprensive reply