Thank you for the very interesting description of your experiments with a 2.2 sub-sat system. In my reading on the subject (at 6moons.com, for instance), I’ve become aware that subwoofer electronics can sometimes introduce a significant timing delay in the speaker output, creating a latency issue with the output from the main speakers. So much so that some users are apparently forced to reposition their subwoofers nearer to the listening chair in order to achieve a proper time-domain blend with the main speakers.
With the KEF KC62 subwoofers, did you encounter any such latency issues? Did KEF provide a latency value for the KC62? Did you make any adjustments in the Anthem STR preamplifier to compensate for latency, or was that unnecessary? More detail about this aspect of your sub-sat setup would be much appreciated.
I didn’t experience any time-related issues like the ones you’re talking about, but I will say a few things that might help shed some light on the topic.
The analog crossovers used in most of the speakers on the market today introduce phase delays—a form of timing error—but this has never appeared to be a problem. Digital crossovers can add timing errors, too. What you’re referring to, however, is latency—in other words, a flat-out time delay as the signal travels from one place to another. It’s kind of like those old recordings of Mission Control talking with astronauts in space—the radio transmissions were delayed getting there, as well as getting back.
I suppose this kind of delay, if it exists, would be attributable to the design of the subwoofer itself. Since I didn’t experience this problem, however, I didn’t feel the need to ask KEF anything about the KC62’s latency.
But what’s probably most relevant in my setup is the Anthem STR preamplifier and its associated ARC Genesis room-correction and bass-management software. The sophisticated design of the preamplifier and software seems to deal with phase and other timing issues, as well as the frequency response. Most people I know who have tried to create a topflight sub-sat system didn’t have equipment like the STR and ARC Genesis, which could account for the problems they experienced, and why they had to resort to creative solutions to overcome them.
As far as placing the sub near to the listening position goes, you have to consider this: Moving the subwoofer from, say, around where the speakers are to the main listening position changes the timing relationships of the subwoofer and main speakers to the listener, but it also affects the frequency response of the sub as it plays into the room. Therefore, the listener might attribute the sonic improvement to the time-domain changes, but it could also be an improved frequency response that they’re hearing. Or maybe it’s both things, or something else entirely. But without more experimentation, including various in-room measurements, it would be difficult to know for sure what’s really happening. Just know that what I did didn’t result in any time-related problems like you’ve described. I hope that helps.