Anyone listen to Zu Audio's Definition Mk3?

Spirit,

I answered this question in a previous post. The five sub controls are interactive primarily insofar as the outcomes of anyone one control's settings acoustically may (likely will) influence your preferences on some of the others. If you change the hinge frequency, you may want or need some adjustment to the PEQ or the level, or both, for example. The phase setting may be more benign to other preferences but even that can influence level, PEQ and hinge preferences. What I wrote in my prior answer was that I do not see the five tuning options as being unnecessary complicated nor preventative of finding appropriate bass performance reasonably quickly. The new control options are not so simple as having only one level knob, but are far less tweak-inducing than a full spectrum parametric EQ and X-over combination. I think Def4 is pretty easy to dial in, and the controls are sufficiently intuitive to be usable by both experienced and novice owners. The primary enabling or inhibiting factor is the user's awareness of what to listen for, or whether they have either an intuitive or finely-honed sense of what sounds "right." Unless, that is, you're measuring, have the gear, and understand what's actionable in the resulting analysis. Not to mention, how obsessive are you -- do you know when to quit?

Phil

Phil, if I knew when to quit, I would have put my wallet away when I paid c$15000 for my first high end system in 1996, and not gone on to spend another c$85000 with never ending upgrades (Zu Def4s pending)! Ha ha!
You're right re prev post, I just wanted to know if control settings were intuitive to get right one at a time esp if they interacted with other settings.
I do know another (non Zu) listener who has an outboard active amp for his bass module with v.similar controls who uses dsp shaping (behringer?) to get correct levels for his room, and wondered if this at all is a route to go down with the Def4s.
Have pretty much settled on the Gloss Black finish, may go from never ending sub bass adjusting to never ending spkr polishing!
I really value your no-nonsense attitude to combining engineering principles and listening experience in your final opinions-can you peruse a couple of items that fit between pre and pow amp and tell me what you think?
First is BSGT QOL, second is NEUTRALAUDIO X-DREI. Both have threads on A'gon in Amps forum.
Marc

213,

I heard the Def4 set up by Zu at a Zu party in Atlanta with all Zu wire and what I would call OK gear. Not very good results. Even installed my Lampizator Dac into the system and it didn't even begin to help the sound coming out of the 4. My 2,which was the Def4 pervious owner, far outran the sound coming from his system. The 4 will not out do a 2 with Ford Focus gear and I heard that to be true. My friend was there and when we got back to FL and heard my 2 he was in stitches with laughter as the 2 was so much better.

I find it very hard to believe you heard Atma/ Tenor amps on your Def and that they moved you away.......what Tenor amp did you hear?

You are a good salesman but you are not going to convince those of us that hear huge sound differences when upgrading to, yes more expensive gear.

You can try and explain this away but what we heard will not be forgotten.

Marc,

In most rooms, when you get new Def4s, you should start by running the sub Volume control at max (10) and as the driver breaks in, you'll likely back off from that over time. If 10 is too much just dial in what's right. Then starting at about 48Hz for the hinge frequency on the low-pass filter, experiment. You'll find the right handoff in the 38Hz - 50Hz range, and again break-in of the sub driver may nudge a change.

As with Volume, start with the PEQ Gain all the way up and adjust subsequently. For the PEQ Frequency, Zu's suggestion was to start at 31 and work around that centerpoint for the right balance. I agree with that so far, at least nothing about my room or system argues for finding balance around the extremes. Start with 0 Phase shift. You should twirl this to hear its effect and return to 0, listen, and tune from there if you hear advantage. I'd move from 0 conservatively. Doing initial setup through this order of priority, one at a time, will give you a feel for the acoustic interactivity of the controls.

An analyzer can't hurt -- even some of the iPhone analyzer apps can be very helpful if you are not confident of your ability to get it right by ear alone.

My general preference is to put nothing between the pre and power amplification. I have a *very* high bar for processors of any type to get over to justify making an exception. I haven't heard the QOL nor the X-DREI, though know about both. From people who have heard the QOL whom I know, reaction was that it seems successful in restoring tonal completeness to solid state amps, and that it is much less contributive to a high quality tubes sytem. That suggests that something like the ASR, which has come up in this thread, might benefit from QOL, since that amp sounds tonally incomplete to me irrespective of its resolution. That's not-uncommon problem in solid state still, even as silicon amplification has conclusively evolved past its once-common characteristic harshness. In any case, over decades of involvement in this pursuit, one thing is consistent -- processors generally don't last long in systems, so I'm open to hearing and being persuaded, but I am intrinsically skeptical about lasting value. I expect to hear a QOL for the first time in a few weeks.

As for X-DREI, it's intriguing but if you look at their own data, you can see that the processor alters every category of waveform fed into it. So is it a fidelity device or just euphonic? I don't know until I hear it but it has to be transformative to win consideration from me. In both cases you can buy/try/return so if you're game, go for it.

Last, regarding these two devices and anything else like them: Both companies deliberately obscure explanation of how they work. Both do it under pretext of protecting their IP. Well, in the tech game, your basic obligation is to innovate for value and then run faster than everyone who might chase you. As long as both companies refuse to explain what their devices do to the signal and how they do it, demand will be truncated and their impact on the market will be limited. It's their choice. At least with the Stein Harmonizer H2, the developer says flatly that his device relaxes the acoustic "stiffness" of air. He doesn't explain how, but he's not putting his device in my signal path either. If you're passing my system's signal, tell me exactly what you're doing with/to it.

Phil

Glory,
Being the owner of the Def 4's you heard and being the former owner of the actual Def 2's you currently own, I will totally agree with you that the sound coming from them at the party was awful. They were essentially plopped down in the room with 0 hours on the speakers and all of the cabling in the system, an amp with an output transformer dying(I didn't know it at the time), and a turntable with a ground loop hum. We could have inserted the best source ever made and it would have sounded terrible. However, now that placement issues, burn in and complimentary component matching has taken place, I can honestly say the Def 4's are so far superior to the 2's in every way that 213Cobra has described that you won't recognize them as the same speaker in my room if you heard them again. I have owned the 2's, owned the 2's with the nano upgrade (which is a nice step forward in terms of transparency, micro and macrodynamics) and now the 4's and it's not even close. I would take the 4's with home depot lamp cord and radio shack interconnects over the 2's with unobtainium cabling.
I am sorry that you had to hear the 4's under the conditions you did because the sound was truly awful that day but I can say without question the 4 is vastly superior to the 2 once setup properly and burned in (assuming complimentary components).