Influence of DC offset on bias

Speaker sensitivity can only tag volume level difference of channels when you listen realy quiet. There also factors to mention such as stereo volume pot. Other than that it has nothing to do with speaker sensitivity.

Of your amplifiers, I'm only familiar with the circuit in the GAS amps . . . and both are fairly representative of a common-practice solid-state amp with an emitter-follower output. The complimentary diff-amp is kinda fancy but by no means unique, and the Ampzilla's bootstraped outputs are typical of many higher-powered amps of the era.

So to answer your question, small amounts of Vos are really only possibly of concern to your woofers, in terms of a static displacement in the voice-coil position or eventual loss of magnetic flux. While there is indeed a small difference in current between the halves of the output stage as a result of a DC offset, the optimum bias point in a Class B amp is dependent on the voltage between the output transistors' emitters, not the current through the output stage. And yes, they are sometimes the same thing in practice, but if you were to change the value of the emitter resistors, the optimum bias current value would also change. And since the bias generator sets the voltage between the two halves of the output stage (not relative to ground), the presence of an offset doesn't change the transfer function of the output stage.

The main issues with output stage biasing are how well it's maintained with variations in temperature and line voltage, and how much an increase in signal current affects the linearity in the crossover region. And these issues span everthing from circuit design, the characteristics of the transistors themselves, the layout of the wiring and circuit board, and the physical packaging and thermal design . . . there are no universal solutions.

Okay, Kirkus, you've clearly discerned that my issue is about what ends up reaching your ears. So is this why I hear an audible imbalance when using my multimeter I achieve identical specs and afterward complete the procedure while listening to music when I adjust the bias?

A SS amp without autobias circuitry or stabilization of quiescent current faces these following problems also previously mentioned by Kirkus:
1. due to the age the parameter mismatch percentage increases.
2. due to the temperature and other room conditions mismatch increases unlike vacume tubes.

There are quite large number of quiescent current stabilization circuits designed and created so far and they have advantage or disadvantage of one to another, but the best ones IMHO is implemented in Bryston amplifiers.

Up until before this post I believed that every SS amp post mid-70's will have it as a matter of fact and quite frankly, I'm shocked of what so-called 'purists' are able to build these days. If you somehow will be able to shoot me the circuit diagram, I'd like to take a peek on that.

As to Meridian 559, I'm surprised. It should be something else on the signal path such as loose wire(interconnect?), solder joint, preamp volume pot etc...

I have no schematics but the LSR&D amp was designed by Marshall Leach at Georgia Tech University and is the well known Leach Low TIM amp. Few were commercially produced and subsequently became a DIY project for which Dr. Leach provided parts and instructions via mail order. It's easy to find schematics for this amp just by googling. There was nothing wrong with the 559 as far as I could tell. It functioned as it should. It was just unimpressive. All of the other amps I've mentioned sound better, the Leach being the best of the lot. The Ampzillas are a close second, Bedinis third and finally the 105's but only because they begin rolling off right at 20hz. It's probably why they sound so good otherwise.