Anyone HEARD the qol 'signal completion' device?

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.

I’ve 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, I’ve been listening almost exclusively to Trifield for the past few months.

Meridian’s 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 doesn’t 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. Let’s say I took a limited frequency band up to, say, 3kHz. I’d let that play. Then I would take another band-limited signal from 3kHz to 6kHz and put it in the opposite phase. Now they’re playing together. They’re not interfering because the two are not really playing the same frequency simultaneously, If you keep doing that with other frequency bands, it’s 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 QOL’s 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

I have had a QOL in my system for about a month (speakers are Maggie 20.1's). All I can say is that Robert Harley in TAS articulated my experience to a "T". EVERYTHING he said is true. I could not have said it better if I tried.

Gcsakakini, Glad you like the Qol. I have had mine for over a month. I could never go back now. I leave the Qol on all the time.
Did you happen to notice what I posted above? When I moved my speakers a little, they locked in place and the dyanmics really shined.
That's probably why the 6 moons review on the Qol was so confusing. They used 7 different unfamiliar systems that were'nt really dialed in.

I have been listening to the QOL for a week in my system. For details on the system pls see the audiogon systems section. The QOL is set up after preamp and before amps via xlr connections. Here are some subjective and objective observations (generally corroborated by more than one listener):
-when we ran a signal sweep we got the exact same frequency response but 2db higher
-although I have not measured it, perceptive change in volume is different between recordings and ranges well above 2db on occasion
-the stereophile comment of instruments sounding like they are “illuminated from within” is our own experience also
-soundstage grows significantly both in width and in height. My speakers are 4 meters apart and throw a 6m stage usually, with this device we get another meter (3 ft) depending on recording. That is not subtle
-where I differ with some of the positive reviews is that this change in stage comes with two negatives: imaging and depth. The sound is a bit more flat and imaging detail in this system is worse. The tight controlled and “you are there” instruments we hear normally become very pleasing to the ear but a bit more diffused. I think it is subtle enough that in a less resolving system it may not be noticed but here it is obvious and it is a real issue since this extra believability is quite important for a lot of recordings
-the main effect I get is an increase in ambiance. My ears feel like they do when I play an out of phase recording (eg in XLO’s test CD). I therefore assume some out of phase information is added. The in phase info is not lost obviously, hence the greater sense of envelopment in ambiance. The cost of this is what I described earlier
-the effect differs from recording to recording. In general it is a pleasing improvement but sometimes not (especially where specific instruments are prevalent and the loss of imaging is bigger)
-I find the built quality to be the equivalent of a $300 CD player with the exception of the larger faceplate. The buttons are terrible and the device tends to send surges of signal when turned on and off (my other equipment doesn’t do that). The circuity looks very simpe to replicate and my guess is that it is very very cheap to make (this guess is not corroborated by any expertise, just the fact that the amount of electronics and their quality are much less than what you would find if you opened a cd player from pioneer)
-the s/n ratio is much lower than my other equipment so that is not good. I assume the best implementation will be if and when preamp makers decide to stick this in the preamp itself