This topic has generated quite the buzz. I've read and skimmed through most of the posts, and I could be wrong, but how does the QOL differ in concept from the old, traditional graphic equalizer? Sounds like A Hi tech, futuristic, advanced improvement on a very old concept; a device that takes into account the limitations of one's listening environment.
Anyone HEARD the qol 'signal completion' device?
An ad in TAS... touting this box. I remain skeptical but would like to know what your impressions are if you have heard whatever it does!
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Interesting. I was playing around with different locations with my speakers and I noticed that depending upon their placement, my speakers sounded louder. When I moved my speakers closer together (maybe 2 feet closer) the music lost some of its dynamics and sounded softer. When I found the right spot which was much wider, the music became more dynamic and seemingly louder. I have never experienced this before. I mean, I have moved the speakers before in and out, side to side, to lock in the center image and bass and so on. But, never has the perceived loudness increased. I wonder if this was due to the Qol. Any of you Qol owners noticed this? I need to try this again without the Qol in the system. |
Ive just read through this thread with considerable interest. I have not heard the QOL, but from what I can tell from this thread and from the information on the BSG website, QOL is designed to accomplish something very similar to Trifield, the signal processing developed by Geoffrey Barton and Michael Gerzon. Although Trifield involves three channels rather than two, both Trifield and QOL manipulate the perception of the soundstage in two fundamentally similar ways... 1. WIDTH. The manipulation of Width expands the soundstage on the x axis. Trifield manipulates the perception of Width by calculating the sum and the difference of the L and R inputs, then amplifying one or the other. You can see a schematic of a typical Trifield circuit here. The Width parameter in the Trifield circuit is similar to the Mid/Side parameter described in the article that Onhwy61 mentioned, which says The M/S approach essentially considers it as being comprised of central and side elements. The Mid signal is the mono sum of both left and right, and basically describes those elements present in both channels. The Side signal is the difference between the two channels, and describes those elements that contribute to the stereo width It follows from this that the balance between the Mid and Side signals determines stereo width. Even though Trifield involves a third channel, the same basic principle determines the perception of Width. 2. DEPTH. The manipulation of Depth expands the soundstage on the z axis. Trifield manipulates the perception of Depth by adding group delay to one or more channels. Again, Trifield employs three channels whereas QOL employs two, but a similar principle seems to be involved. Together, the manipulation of Width and Depth can create a very spacious soundstage, far more spacious than the speakers and the room would seem to permit. I know this from personal experience, as I have listened to Trifield extensively on my Meridian G68. In fact, Ive been listening almost exclusively to Trifield for the past few months. Meridians implementation of Trifield allows the user to set the values of Width and Depth, so he can tailor the soundstage to his particular room and taste. For my own taste, a small amount Width and Depth manipulation yields the best results. The BSG website doesnt reveal a lot of design details, except in a very abstract way. In his interview with RH, QOL's inventor Barry Stephen Goldfarb says this... Essentially the idea was to get out of a single signal both the in-phase information and the out-of-phase information I began to try to figure out a way of tricking the signal so that part of it would play and another part might be cancelled. I then tried layering different frequency paths. Lets say I took a limited frequency band up to, say, 3kHz. Id let that play. Then I would take another band-limited signal from 3kHz to 6kHz and put it in the opposite phase. Now theyre playing together. Theyre not interfering because the two are not really playing the same frequency simultaneously, If you keep doing that with other frequency bands, its like weaving frequencies. A group of frequencies will be in-phase to a limited bandwidth; another group of a different bandwidth will be out-of-phase; and I would add these layers until the entire audio bandwidth from 20Hz to 20kHz was covered. That technique produces a whole audio signal We call it in our patent Phase Layering. The band-limited manipulation of phase is also found in Meridian's Trifield. Meridian's implementation of Trifield is digital, whereas QOL is analog, but again a similar principle seems to be involved. None of these comments are intended to diminish the value of QOL. My own personal experiences with Trifield have led me to conclude that soundstage manipulation, when executed well, can yield very pleasing results. Judging from the owners who have contributed to this thread, it sounds like QOLs execution is excellent. I agree with the observation that the desirability of soundstage manipulation is, to a significant extent, recording specific. It is for that reason that, IMO, a little goes a long way. Bryon |
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