50mm drivers are common in high-end gaming headsets, where entry-level and mid-range headphones / headsets will typically be seen in 40mm sizes. The larger size allows for better low frequency (bass) extension for crisper, deepr lows that add an extra dimension to music and a bit of extra "oompf" to that rocket you just fired. The larger drivers also allow less "push" to create an equivalent volume of sound, so they tend to lend well to crisper-sounding audio, especially at high volumes or when there's a "cluster" of noises at once, such as your buddies trying to shout commands while all hell is breaking loose.
The audio quality did not disappoint despite relatively high expectations we had coming into reviewing the FREQ5 headset. Sound "feels" as though it's emanating from the room and not blasted into your ears from an inch away (which it, well, erm, sort of is), which gives a realistic, immersive sound especially pronounced in FPS games. A crisp fidelity exists that allows you to pinpoint those creeping footsetps alongside the action in the distance. The bass response, the category that I'm especially picky about (because it's so hard to find that perfect balance between too boomy and not enough punch) left me feeling satisfied. Listening to bass-heavy music is a pleasure, and does a great job at hitting very low notes crisply. Bass doesn't feel forced, which is ultimately what you're looking for. So bravo, Mad Catz, you've made me happy here.
Now, about that "balanced" sound I referred to earlier. Many times companies realize the impact bass has on first impressions, and they'll put alot of design focus on good bass, but then the rest of the highs and overall fidelity goes to crap. However, the fidelity and clarity of the mid and high ranges is fantastic, which makes music listening a joy with the FREQ5s. I use in-ear and studio monitors in my home as my "reference" for music, and these really do shine. I'm listening to some calm, flowy classical now as I write this, and the FREQ5s are crystal clear (if I listen closely you can hear guitar pick scratches and nicks, the gentle thump of a piano sustain pedal; all little details you expect in a high-fidelity audio setup).
Conclusion: they sound damn good. Great (and smooth) bass extension, great clarity / fidelity, and well-balanced and crisp response through the frequency spectrum.
I'll keep this short and sweet; these are really comfortable.
Alright, fine, I'll elaborate a bit. The headset applies a little pressure which gives a comforting snug fit, they don't wobble much even when I'm spazzing like your favorite rockstar. The earcups give plenty of room around your ears so they feel roomy and the padding is soft without feeling mushy and cheap. The only downside is these are well-built, and thus unavoidably on the heavier side, but I haven't noticed any significant side effects of that weight yet, and they remain comfortable for hours. And if they get a little unwieldly, just rotate the earcups so they rest on your shoulders, just like Mad Catz intended.
The microphone is maybe even somehow my favorite part of this package in that it's probably the biggest differentiator. The head is large so it captures more of the sound of your voice, and the noise-cancelling features produce extremely clear audio that sounds very natural. I've even gotten unsolicited comments from my buddies when we are in a chat that the audio is super-clear, and lending it to a friend so I could experience it, I could also tell the difference. It's the best gaming headset microphone I've had the pleasure of testing... there, I said it.
The only letdowns we can find with the FREQ5 invove controls and tweakability. The volume roller is easy to find but doesn't offer any feedback on volume level by feel (it could be at max or min, but you can't tell until you listen) and you really have to roll alot to change the volume a noticeable amount. Likewise, there aren't any indicators of which EQ setting you're on, again you just have to listen for what you want at that time. Otherwise the buttons are well-placed and easy to find / reach without thinking about it. Also, there isn't any software-based tweaking like EQs or virtual surround, which might be a bummer to the hardcore gaming audience Mad Catz is likely to be targeting. The out-of-the-box EQ settings have met my preferences though, so I haven't had much a gripe with it, but I probably can't speak for alot of you out there.