After the system was set up to my liking I ran the speaker test just to confirm all the channels were working. As expecting everything was set up properly and worked without problems. The Audio Control Panel integrates well with Window's own audio controls and is a much more user friendly interface than most sound equipment.
Testing the sound card was a relatively long process because it including general use (music, movies, workstation) and gaming with both a speaker system and the HP-1 headset. There is no reason to drag through all the minutia, but it should suffice to say that the AC-1 brought a noticeable improvement other the onboard sound from my Asus M2N32-SLI motherboard. For many people sound is sound, but the improved quality and the ability to further customize with an add-on sound card, especially a higher end one, is easy to appreciate. Higher end speakers will of course be better able to follow through with the improved sound quality.
During gaming is when this card was at its best. For this testing I focused on the HP-1 instead of speakers, not only because they are designed to work together, but I tend to game in headphones. Razer's material on the card says to expect better directional perception, optimized audio signals, and improved realism, and these claims can't be refuted. Using the HP-1s, which I enjoy, there was a considerable improvement over the onboard sound. The audio's highs and lows were improved and the audio was finer so pinning down exact sounds and their relative direction is much easier to do. The explosions had more weight to them and the staccato of gunfire could hardly be compared to my old setup.
Conclusion
I have to admit, I generally use my motherboard's onboard sound, but the last generation of sound cards are really winning me over. These AC-1s and Creative's Sound Blaster X-Fi cards are making serious progress in sound quality and audio controls. Despite high price tags, they are bringing great listening experiences to users who are not audiophiles and might not have the time or knowledge to really tweak their audio setup.
As for the AC-1 sound card it is expensive and, if you have a motherboard with onboard sound, not necessary. Furthermore, it is best used with the HP-1s which are not cheap. I was happy with the performance of my speaker system, but gaming in a good headset is, in my opinion and that of my neighbors', the best way to do it. You are not limited to the HP-1s, other companies have cheaper alternatives, but there is the urge to go with the full package.
The system has a few minor flaws, like that the software might be a bit too much to deal with and that the card can't run speakers at the same time as the headset (unless you use the optical). Another detail to keep in mind is that if you are switching to a video card to get better performance (through decreased load on the CPU) you should not expect much of a gain. Our system only realized a gain of a few FPS, generally fewer than four, so this is not a cost-effective upgrade, at least as far as performance is concerned.
Overall, I would say that Razer accomplished what they set out to do. The AC-1 Sound Card is capable of bringing users a high quality listening experience that offers lots of customization, and is great for gaming. I noticed an improvement in my gaming and general use so was happy with the upgrade, but there are a lot of other options to try, such as the Creative X-Fi series, which has gotten a lot of great press. One thing Razer was able to do, which I really appreciate, is to make this card for gaming. The drivers see that gaming needs are taken care of and ESP and Fidelity technologies both shine through while gaming.
