Is DEQX a game changer?

Good progress Al. As you mention, over the coming days when you start to evaluate by listening, I recommend you play familiar music, preferably with a fair amount going on in the bass frequencies. It's at this point that you may choose to vary the correction limits slightly and load four marginally different configs to compare how they sound side-by-side.

As you become more familiar with the software, you may repeat this several times until you arrive at exactly what you want. Nothing beats playing the most 'challenging' music in your collection and making minor corrections until you have eradicated every possible irritation. In my case, I am quite inquisitive and experimented by slightly changing the correction limit frequencies, amplitudes, crossover points, slopes etc until I learned the impact of each variable. All the time keeping close to the original recommendations of Alan Langford and the DEQXperts I consulted. The only aspect that I have never modified is the original measurement window boundary.

This took around six months or so because I am also dealing with digital crossovers and time alignment to two separate subs which in themselves needed alignment together so the setup has more complexity and variables. More than two years later I have not found any music that needs me to change anything so the effort was well worth it.

Thanks, Andrew (Drewan), for your always valuable inputs.

For the time being, at least, I’ve completed my assessment of the two correction filters I described in my previous post. The clear winner was filter 2 (the one that was created from measurements taken at a 42 inch distance), vs. filter 1 (created identically except from measurements taken at a 30 inch distance), and vs. bypass mode (which was outperformed by both filters), and vs. the several filters I had tried some time ago which were created from measurements that were compromised by close placement of the acoustical panels I used.

Most of the evaluation was performed with classical music, which is what I and my wife primarily listen to. Some rock, pop, and folk was also included. The degree of the differences between filter 2, filter 1, and bypass mode varied widely depending on the recording, ranging from barely perceptible to quite dramatic.

Perhaps most notable among the differences that I and my wife perceived were on some recordings having overly bright string sound, including some string quartets as well as symphonic recordings. Those became much more enjoyable with the filters engaged. Not because the sound was dulled down, but because there seemed to be increased detail and improved definition in the upper midrange and lower treble, as opposed to a more homogenized presentation of those notes, which in turn resulted in the brightness being less objectionable. I recall that some time ago, either in this thread or in the “sloped baffle” thread, Bombaywalla had commented that time coherence will provide benefits along those lines. Both this experience and many previous experiences I’ve had comparing sonics between my speakers and my Stax electrostatic headphones have me convinced that he was right.

Room corrections, which I haven’t yet addressed at all, are next in the queue!

Best regards,

--Al

Al and I already traded PMs about his progress. For the benefit of others, I mentioned in PMs to Al that room correction will take him across the goal line.

I also surmise that Al may find that he like a different room correction adjustment for each type of music that he likes. For example, he may like bass augmentation when he plays pop and rock. In contrast, he may like a flatter FR adjustment when he plays classical.

That's the beauty of the DEQX. It enables the listener to fine tune his or her system to his or her specific tastes and preferences.

An update for those who have been following my progress with the HDP-5: There will be a further delay until I perform the room corrections, due to an unrelated issue that has arisen in my system.

I've recently been noticing significant loss of definition on high frequency percussion, especially on high frequency piano notes. That has not been evident with my Stax headphones, however, just via the speakers. Since the headphone amp is driven by an output of the DEQX, in bypass mode of course, that pointed to my power amp as being responsible. And sure enough, when I lightly tapped on its tubes with an eraser, with the amp powered up, I found that one of its four vintage Sylvania 6SN7GTB's had become highly microphonic.

I have a number of other 6SN7GTB's on hand, but I don't want to use them for anything involving critical listening, such as the room corrections, as I had tried them in the amp a couple of years ago and didn't care for their sonics. So I'm ordering some additional tubes ("tubes" plural, as I'll want to replace the corresponding tube in the other channel with one that matches).

I'm pretty certain, btw, that this issue would not have affected the speaker measurements or speaker corrections I have performed. The problematical tube is only in the path of one channel, and the speaker measurements and correction profiles turned out to be very similar for the two speakers. Also, the tube still measures fine on my Hickok tester, and when I performed the speaker measurements the speaker was considerably further away from the amp than when in its normal position, and was pointed in the opposite direction of the amp.

Best regards,
-- Al

Quite the odyssey Al. Enjoy those new tubes!

And how are you liking the DEQX as a DAC to your headphones, relative to other digital sources you have used with them?