Pros: Easy to connect, multiple surround speaker angles
Cons: Poor equalizer, poor volume control
Disclaimer: Many of the problems I note with the DSS2 can also be attributed to the lossy compression of Dolby Digital. However, since the DSS2 is intended to be used as a surround sound processor, I feel it would be disingenuous to review it as a simple headphone amplifier. I believe that most people looking to buy the DSS2 are looking at it to provide Dolby Headphone, and therefore will be trying to run a Dolby Digital signal to the device.
Let's be clear, the Turtle Beach Ear Force DSS2 was made to solve a very specific problem: How do we add Dolby Headphone to a console? For that, it actually does a decent job with its six-position configurable speaker angles and ability to run all of the game audio to the processor with a single TOSLINK cable. I'm sure many high-level console gamers will be pleased to gain Dolby Headphone surround sound and an advantage over their competitors.
What it was clearly not designed for was running PC audio, listening to music, or watching movies. PC users' relative lack of interest in S/PDIF means that Dolby Digital support on PC S/PDIF connections is a complete crapshoot. For the majority of sound cards, no matter that it's onboard or discrete, The DSS2 has no choice but to upsample a 2-channel stream lacking any directional cues. Just in case you own an ASUS Xonar DGX like myself, let me save you the effort and tell you right up front that it doesn't support Dolby Digital. The Intel chipset onboard your work computer's Dell motherboard does, though.
Once the sound is on the DSS2 you had better not touch the equalizer button unless you want a great example of what overdriven, blown out, terrible audio sounds like. The presets (your only equalizer options) are so absurdly heavy-handed that they would actually be better off removing the feature entirely. The DSS2's poor UX starts to manifest itself here, as you have to wait until the full cycle of LEDs plays out before you can switch modes again. Not that you'll be switching often or even should, but the fact that you can't quickly compare EQ modes was a poor decision on Turtle Beach's end.
As you try to adjust the volume, the first thing you'll notice is that the knob has very pronounced detents. The second thing you'll notice is that the volume control is completely digital. The third thing you'll notice is that there is a hard volume floor. To its credit, I couldn't find out if the DSS2 had a volume ceiling, but to its discredit, it can easily get loud enough to damage your hearing or headphones. This is a very poor design for a volume control, which I often want to turn down to "ambient" levels and rarely want to turn up to "headbanging" levels.
Finally, the sound signature itself has two very distracting crystallized and reverberating effects. For electronic music and game sounds this isn't as noticeable, but it completely destroys the warmth of vocals and the fullness of an orchestra. I would go so far as to specifically recommend against using the DSS2 when watching movies or listening to most music.
I can't help but feel like the DSS2 would be a far better device if it were actually designed for one purpose. If Turtle Beach said "make a great console device to add Dolby Headphone", they could have added a belt clip to the back and a USB-rechargable battery for use at tournaments. If they had said "make a great external PC headphone amp", they could have replaced the TOSLINK, analog, and AUX jacks with four 3.5mm inputs and added some ballast to hold itself on your desk. The problem is that they apparently said "we want to sell to both", and made a poor compromise.