Some clarifications to some of the comments in Gammajo's post just above, for the benefit of others who may read this thread and want to consider DEQX:
Seems intimidating to have to take the speakers (mine about 300 lbs each) into the yard....
While it is theoretically ideal to do this, it is not necessary. That was clearly stated by experienced DEQX users in the "Game-Changer" thread I linked to.
The goal of the DEQX speaker calibration (aka "speaker correction") process is to make the speakers time-coherent (and therefore also phase coherent) at all frequencies above a lower limit falling in the area of roughly 200 to 500 Hz (our hearing mechanisms being most sensitive to phase and timing issues at mid-range and treble frequencies).
If the speaker calibration process is performed outdoors, so that there are no room reflections to degrade the accuracy of the process, that lower limit of the range of frequencies for which the process is effective will be as low as possible, within that area of 200 Hz to 500 Hz or so.
If the speaker calibration process is performed with the speakers moved to the center of the room, as far away from reflective surfaces as possible, that lower limit will be a bit higher than if the process was performed outdoors.
If the speaker calibration process is performed with the speakers in their normal position, that lower limit will be somewhat higher still.
So which of those three alternatives is chosen will simply affect how low in frequency the benefits of the process will extend. The mid-range and treble will benefit regardless of which alternative is chosen.
...and then spend month dialing the thing in to get the best from it.
My understanding is that if the DEQXpert service is used, or the comparable service provided by Acoustic Frontiers, the speaker and room calibration processes can be accomplished in a matter of hours. Or at most perhaps two sessions of a few hours each.
In my own case, I don't plan to use those services. And working at my own deliberate pace, having no previous experience with the product, and with the time I can devote to it limited to some extent by other activities and by the need to not perturb my wife's activities by playing test tones and loud music through the speakers (I use headphones when I want to listen at those times), I envision taking perhaps a month or so to get it fully dialed in. But that's just me.
My speakers are designed for excellent time and phase response across a wide axis.
Regardless of what manufacturer literature may say about time coherence, time alignment, phase response, phase linearity, etc., if the speaker has a crossover and if the crossover is not first order (meaning 6 db/octave), the speaker is not time coherent. If the speaker has a crossover and is not made by Vandersteen, Thiel, Green Mountain Audio, and perhaps one or two others, it is highly probable that its crossover is not first order, and that the speaker is therefore not time coherent.
For background on the benefits of time coherence (which in turn automatically implies phase coherence), see the "Sloped Baffle" thread I linked to earlier.
The Lyndorf idea of not changing the character of the speaker and amps etc, assuming people selected them because they liked them, is also logical to me.
Of course, with DEQX one could choose to simply not do the speaker calibration process, and just use some or all of its other functions (room correction, equalization, DAC, preamp functionality in some models, USB interface in some models, etc). But one would be losing out on what with many speakers in many rooms may be its most important benefit, that is not provided by most competitive products.
Regards,
-- Al
