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I tested the Acoustic Edge on several DVD titles, and did some basic A-B comparisons between true Dolby Digital playback, and QMSS enhanced 5.1 playback, and the benefits of either can be quite convincing. There’s definitely something to be said about the overall enhanced surround sound coming from the QMSS processing: music is appropriately phased into the rear, and some scenes where there’s a lot of echo information become an absolute delight as the sounds literally envelop your entire listening area. In Titan AE for instance, the music sequences gain a lot of energy, and scenes like the ice field chase benefit from the heightened information on the rear channels.

On the other hand, some movies are better off in true Dolby Digital, because QMSS doesn’t provide as clear a center channel, nor does it offer the absolute precision of a true Dolby Digital stream (this due to the fact that it is trying to create rear channels from front stereo streams). The great thing is that QMSS isn’t FORCED onto the user, it is merely another option that you can choose to use when playing back movies, and I find that to be a very powerful option indeed.

Having been subjected to a lot of these types of algorithms, the most impressive thing about QMSS with movies is that it works very accurately. You won’t hear too much leakage into the rear channels, and I didn’t once find any inappropriate sound information being sent to the rear channels (like center channel speech, or certain sound effects that should only come from the front). Forward-rear pans weren’t as precise as with Dolby Digital, but I was pleasantly surprised to find that forward-rear pans were actually quite convincing, considering this type of information just doesn’t exist in the original stream. My guess is that a lot of movie fans with personal home theaters will enjoy the QMSS feature on some of their movies, and yet prefer to stick with DD on their other movies. Even a purist will find some scenes in any movie that are actually better off with QMSS than with true DD.

Control Panel: Settings & S/PDIF

What I didn’t prefer about QMSS over true Dolby Digital is the loss of a true center channel. QMSS will attempt to create a virtual, or phantom center channel from the stereo stream, but it isn’t a very good center channel. Understandably so, since a center channel is the domain of true AC3(5.1) streams. If you have ever compared Dolby Pro Logic to Dolby Digital, you can relate to the difference that can exist in the center channel’s information. Sequences with heavy voice emphasis are most noticeably different. Take for example the opening sequence for Titan AE, or The Cider House Rules, where a character or narrator is talking to the audience. There the voices are infinitely more distinct, more clear, and more tonally accurate in Dolby Digital. The opening sequence of Titan AE was particularly revealing, as the virtualized center channel from QMSS gave a much deeper voice to the narrator than was originally recorded and mixed by the studio. It was a distraction to me, because I remember well the distinct qualities of several characters in movies I watch, but it may not bother others. And again, you can turn QMSS off for those movies where it has a negative or distracting effect on the sound.

There are other applications for QMSS outside of playing just DVDs. When you download movie trailers, or play back other video files, chances are they are not encoded with AC3/Dolby Digital audio streams, and here, the ONLY way to get a good surround experience is through the use of QMSS. The great thing is that QMSS is automatically enabled to process all stereo streams. If the sound card detects that you are playing a stereo stream, it will apply the QMSS processing, so you don’t have to do any extra work to have your movie trailers or other stereo movie material playback in 5.1 surround.