Let me start off by saying that I am not a professional audio engineer - only someone who loves surround sound and has been looking into this market of DSP Headphones for about 8 years now.
Will it really matter if a signal is 5.1 vs. 2.1? Will it only simulate 2 speakers in the DSP or can we hear a Digital surround sound processed off of a 2.0 input signal?
While it is obvious, it is important to remember that "almost" all headphones only have 2 drivers in them. So regardless of the signals coming into it, it still only has stereo speakers to produce the sound. From
my personal experience with Digital Surround Processing (DSP), whether it is a 2.1/5.1/7.1 signal coming in, it actually has a very small part as to creating a surround sound effect in stereo headphones. What matters most is how well that DSP can take that info and create a surround effect. I kinda feel like the 5.1/7.1 virtual surround headphone is a gimmicky sales tactic. All this is informing the buyer of is that the DSP can except that type of signal for audio information... it doesn't automatically mean that you will be able to hear a difference between the two input signals
.
For example. I have a sound blaster X7 (DAC/AMP) that i use for gaming. It can take an input of Dolby Live 5.1/7.1 surround sound. However, the Sound blaster has a built-in SB-Axx1™ multi-core DSP chip (SBX) that creates its surround sound effect. I personally think it is one of the best on the market currently.
The catch is my stereo sources sound just as good to me, surround sound-wise, with the DSP on with my stereo content. Yes, it helps me sleep better at night knowing that I can put a Dolby Live 5.1/7.1 surround sound signal into it... but outside my of OCD Audio brain, I cannot tell you that I hear a difference between the two. In fact I have heard more convincing surround sound from a great stereo recording with DSP then a 5.1 signal.
I am in hopes that this new Audeze DSP will rival and be superior to the SBX DSP. This is the risk in buying it before it comes out for full review by many. But it is telling us that it will give a convincing surround sound effect from a 2.0/2.1 signal. Plus if you add the head-tracking capabilities of the headphone, I feel it will make a huge difference in tricking our brains into hearing surround sound out of a Stereo input signal.
Okay... that is my amateur nonscientific expectation, that anyone smarting than me in this area will probably tear apart
, but I can only make my own opinion off of my own experiences.