Is DEQX a game changer?

Drewan77,

How are you using your DEQX? Is it between a stereo preamp and the amps? If so, have you compared the current setup to receiving the digital stream directly into the DEQX and using it as XO/DAC/volume control?

Lewinskih01

I did not require my other preamp because the DEQX does this very well, reducing components in the signal path and it is transparent sounding

It has both digital and analogue inputs, balanced and unbalanced (HDP4 has USB as well but I don't need this)

The DEQX has analogue volume control outputting to the power amps (digital volume option included) and yes, I have used the onboard DAC which is very good, configured as below:

CD transport input to Balanced Digital XLR, onboard DAC, then onboard XO/speaker correction, output to external treble/mid/sub power amps, then to Speakers & subs (likewise for a Digital streamer to coax unbalanced Digital phono input etc)

A Turntable and SACD player use the phono and balanced XLR inputs

One thing that takes getting used to is that the DEQX will make different speakers sound more similar, as in CORRECT. It does something similar for amplification, especially if bi- tri-amping is used. I use tube amps on the top end and class- D amps on the low end, which is something that couldn't easily be done without DSP.

I've been a DEQX owner since 2012 and I'm now on my second DEQX (HDP Express II) and I completely agree with Drewan77. The DEQX is truly a unique product. For me it was a total game changer coming from a very good analog electronic crossover, but you cannot just plug the DEQX in your system, power it up and start enjoying it. In fact, if you are doing it yourself, it takes quite a bit of time and with a complete understanding of the process with its pitfalls as well as the parameters that are to be adjusted in order to get a truly successful calibration. Making a DEQX calibration attempt with an "entry level" understanding may yield noticeably better results than without the DEQX, but almost assuredly you will have left a great bit of improvement on the table that you can try to recover bit more on your next attempt. I've probably done ten DEQX calibrations now on two different systems, and I still learn something new about the process each time.

For a better understanding of exactly what the DEQX does and how it does it, Kim Ryrie, the inventor of the DEQX, in interviewed in a series of YouTube videos you may find to be informative. In one of these videos Kim states that with the DEQX, speaker designers should focus on producing the lowest distortion driver possible and not to worry about phase and group delay issues since the DEQX is quite capable of successfully managing these issues on its own.

One thing that I should point out when you, or even if you are using the DEQX-Expert service to set-up your DEQX is that you really need to use the Earthworks M23 or M30 calibration mic with its associated proprietary DEQX calibration file loaded. The basic Behringer calibration mic and its generic calibration file will get you started, but really doesn’t yield the results that anyone here would probably be looking for.

I have my DEQX configured (currently) as follows:

Apogee Duetta Signature main speakers with GR Research/Rythmik subs
Bi-amp with stereo subwoofers
Apogee ribbons crossover: 920 Hz - 96 db/oct linear slope
Subs to Apogee bass: 80 Hz - 24 db/oct Linkwitz-Riley slope.
Subs time aligned to the Apogees.
Speaker correction above 500Hz.
Conservative amount of room correction below 110 Hz.

Thanks Forrestc ... still trying to drag the DEQX rep out to my house. Maybe he's using a strategy of sales foreplay. Dunno. Hopefully this week.

Btw, your point that "Kim states that with the DEQX, speaker designers should focus on producing the lowest distortion driver possible and not to worry about phase and group delay issues since the DEQX is quite capable of successfully managing these issues on its own" makes much sense.

My Paradigm S8s (v3) use well made drivers that produce very low distortion. My main gripe has been the crazy impedance and phase angle curves. Fortunately, my Ref 150 has the muscle and robust power supply to handle that roller coaster. I use the 4 ohm taps which "taps" (pun) down voltage output variations as a function of frequency response to a small amount.

I am optimistic that the DEQX will make a big difference ... if I can get the rep to engage.

Hopefully, will report back soon.