The DEQX HDP-5 ($6500) Roon Ready digital-preamplifier includes DEQX DSP-based room correction and DEQX digital crossovers and calibration. I'm not going to type any specs or explanations since you can find all that on the DEQX website. I will, however, share something of greater importance. From my notes about the A/B/C comparisons:

check out DARKO's review of the DEQX with the KEF LS50s

"Shit works."

System: VAF i93 MKII Signature loudspeaker ($16,000/pair), REDGUM Audio amplifiers; RGi35 ($2500) on the tweeters, RGi60 ($3500) for themids, and the RGi120 ($4500) diring the bass.

bubblewrap's picture

Am I correct in thinking that such processing cannot be carried out on MQA?
"MQA requires a lossless transmission system from the file source to the final D/A converter. Benign DSP processes such as a digital volume control (used in moderation) immediately defeat the MQA decoding. The same is true for digital crossovers, digital EQ, and room correction. The MQA stream will be corrupted if any of these common processes are encountered."
I have been using fully active DEQX-style speaker correction for years, and the measurable (and, I would say, audible) improvement is huge. MQA is a tiny, tiny theoretical refinement at the outer edges of what any human can hear - putting it generously. It seems a shame to throw away the former in order to get the latter.

Is there a plan to integrate MQA with these common 21st century techniques entirely in the digital domain? With ordinary PCM, DEQX-type innovation can be developed 'open source' by anyone with an idea. Will it always be this way?