Fix the biggest problem with your system: the interaction between your room and your speakers. Especially in difficult rooms, this makes a more significant difference than any other improvement to your system. Also, this is the very best way to integrate subwoofers seamlessly. Free shipping in CONUS. No PayPal fee.
This is a preamp, DAC, speaker correction and time correction software and hardware, so picking a category is a litte difficult. Free shipping in CONUS by FedEx Ground.
DEQX uses real measurements of each individual speaker to generate a precise correction filter that restores the amplitude and timing coherence of the acoustic signal from the speakers. Only after the individual speakers are calibrated for true high fidelity does DEQX correct for the room's acoustic modes – resonances present in all listening rooms that muddy and confuse the bass region. This will resolve the digital/analogue domain debate for you by just toggling between on and off. It makes a remarkable difference.
This unit contains a DAC and is designed for stereo and the incorporation of a subwoofer. It is the only way to incorporate a subwoofer seamlessly into a stereo system, giving clear bass notes. You will be able to discern the distinction on well-recorded songs between a bass guitar note and the kick drum.
Nothing tames a difficult room better. I have two of these units and am selling one because I am moving up to Bel Canto Design Black EX, which should be able to handle the easy room (bass region only).
You will need a microphone stand and a high quality microphone to set it up. I do not have the standard calibration kit.
I will put you in contact with the engineer, Larry Owens, who can set this up for you. He is in Denver and will take over control of your computer; you will move the microphone at his direction. (He noticed I had a microphone at the wrong angle when he was taking measurements.) Do not do this yourself.
There are a number of reviews. Check the DEQX home page.
From Stereophile 2017 Class A Recommended Components:
DEQX PreMate D/A preamplifier/equalizer: $4995
In a field where, as KR puts it, "all automatic EQ systems conflate speaker correction with room correction," the DEQX PreMate stands out: In use, this DSP engine begins by measuring and analyzing the speakers—in exclusion of the listening room, to the greatest extent possible—then generates filters to correct frequency response, optimize time alignment, and, if desired, create a customized active crossover for that speaker. After that, the user can, if he or she wishes, completely discard the speakers' internal passive crossover components (although that's not required). Bass management and, ultimately, room correction can also be implemented with the PreMate: icing on the cake. The PreMate Incorporates a volume control and switches for choosing—or not—from three preprogrammed configurations. The usual variety of connectors provide S/PDIF, AES/EBU, TosLink, and USB inputs; there is also an XLR input for a calibrated mike (included), plus a variety of analog outputs, to use for the main stereo channels and subwoofers. Apart from noting that "the learning curve is steep," KR was unequivocal in his praise for the DEQX PreMate: "It made my very good speakers undeniably better, smoother and cleaner." (Vol.37 No.12 WWW)