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
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