AVS Forum Addicted Member
Join Date: Feb 2010
Location: Monument CO
Mentioned: 30 Post(s)
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Good grief this has degenerated!
I used to work as an electrician and often handled live wires. How much of a shock is felt is dependent upon many variables. A better analogy might be to think of a battery. If you do not load it, the voltage (potential) is still there. Apply a load, and due to internal resistance and cell capacity the voltage will drop a little, increasing to a lot as the load becomes large (i.e. a smaller resistor).
I read Amir's post a couple of times but am practicing and chasing some work stuff so just didn't quite grasp it. I will just note that IME (that is important!) the transformer may be the limiting factor for many AVRs because not all channels are required to provide full power all the time. Big transformers cost a lot and take up a lot of space. For many amplifiers the limitation is the decoupling (filter) capacitors as they cannot support the charge needed for continuous large signals and allow the rails to sag. Even with separate (distributed) capacitors, if the rails sag in one channel, with a single supply that will begin to draw from the others and the entire rail sags. The output transistors drop more voltage as current increases, another source of reduced output voltage, and this parameter is independent of the other channels (to first order). Etc. There are so many variables from amp to amp and system to system, and so many different components out there, that I find speaking in other than general terms can be dangerous Somebody can always find a counter example, be it the behemoth amp that doubles down to 2 ohms or the speaker that exhibits below 1-ohm impedance over most of its bandwidth.
My belief is that for the vast majority passive bi-amping is a waste of effort with negligible audible benefits. The theoretical pros and cons are pretty clear, but there will always be those who claim to hear benefits present or not (expectation bias, and in some case actual differences such as changes in level and such produce a perceived benefit that is not fundamentally due to passive bi-amping but a different change in the system). While Amir makes some good points, I tend to lean with Arny in that in the real world and at usual volumes with typical speakers current limiting is less an issue than voltage clipping, usually due to flat-out asking an amp to deliver more voltage (and thus power) than it can provide. I tend to post during breaks and so have not really kept up with all the opinions; Arny and Amir are both known to me (and me to them), at least in a 'net kind of way, and I respect them both. That said, IME, which includes simulations, a few measurements, and only a couple of trials, I have observed no benefit with passive bi-amping.
I am not into picking winners and losers. Each of us has presented our case with varying clarity and passion, and it is up to the reader to decide. Sometimes the only answer you will ever get is "because I believe/hear it". As an engineer and audiophile I tend to do my own research when something is not clear, either reading a text or refereed journal, measuring and listening tests, or both. As a musician I keep reminding myself that ultimately I am listening to the music, not the gear, and should find better things to do than argue on an audio forum where I am unlikely to convince either side they are right or wrong. Or someplace in the middle. On the net it can be very hard to determine a poster's credibility. Some here have found my profile on Linked In and so forth so at least know some of my background and experience (though none of my audio experience is there, not really relevant to my primary career), other names are well-known in the industry. But there are extremely talented, intelligent, knowledgeable folk that most would not know, names they would not recognize, and grade-schoolers with a PC who can present themselves as Einstein. Can be tough to sort out...
In the meantime, I need to get back to practice. Why every cantata arranger feels they must tweak the key and rhythm of the classics I'll never know, but at least there's lots of fun stuff different from my usual orchestra and big band gigs...
FWIWFM, IMO, my 0.000001 cents (microcent), etc. - Don
"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley