A discussion of modern DSP would not be complete, IMO, without mention of DEQX. In addition (depending on model) to being able to serve as a preamp, provide remarkably transparent A/D and D/A converter functionality, extremely versatile and flexible room correction capability and equalization capability, and the ability to support subwoofers, biamping, and triamping, as far as I am aware DEQX products are unique in that they can bring any speaker that is not time coherent much closer to being so. And the great majority of speakers are not time coherent, including all speakers which have a crossover that is not first order (i.e., 6 db/octave). (Vandersteen, Thiel (at least formerly), and Green Mountain Audio are among a small handful of manufacturers of speakers which use first order crossovers).
That said, using a DEQX entails a very substantial learning curve. Also, taking full advantage of its "speaker calibration" (i.e., time coherence) function requires making close-up measurements (e.g., from a distance of 2 or 3 feet or so, depending on the size of the speaker) of the speaker’s response to test tones generated by the unit, with room reflections reduced to a bare minimum. Reducing room reflections sufficiently can mean moving the speakers to the center of the room for purposes of that measurement, or even better to outdoors. Room correction is performed subsequently, as a separate step, with the speakers in their normal positions.
I use DEQX’s top of the line HDP-5 model, and it took me several months to fully optimize its settings to my satisfaction. And that was with a relatively simple setup involving a single pair of speakers running full-range. Although I chose to do it all myself, at my own methodical pace, rather than utilizing the services of a "DEQXpert" via the Internet, who I understand can greatly speed up that process and presumably accomplish it better than many users would be able to.
For further info, and considerable additional detail on the experiences of a goodly number of members with DEQX products including me, see the following long-running thread:
https://forum.audiogon.com/discussions/is-deqx-a-game-changer
Regards,
-- Al
That said, using a DEQX entails a very substantial learning curve. Also, taking full advantage of its "speaker calibration" (i.e., time coherence) function requires making close-up measurements (e.g., from a distance of 2 or 3 feet or so, depending on the size of the speaker) of the speaker’s response to test tones generated by the unit, with room reflections reduced to a bare minimum. Reducing room reflections sufficiently can mean moving the speakers to the center of the room for purposes of that measurement, or even better to outdoors. Room correction is performed subsequently, as a separate step, with the speakers in their normal positions.
I use DEQX’s top of the line HDP-5 model, and it took me several months to fully optimize its settings to my satisfaction. And that was with a relatively simple setup involving a single pair of speakers running full-range. Although I chose to do it all myself, at my own methodical pace, rather than utilizing the services of a "DEQXpert" via the Internet, who I understand can greatly speed up that process and presumably accomplish it better than many users would be able to.
For further info, and considerable additional detail on the experiences of a goodly number of members with DEQX products including me, see the following long-running thread:
https://forum.audiogon.com/discussions/is-deqx-a-game-changer
Regards,
-- Al