Ponzio. I think you have asked an improtant question that does not have a simplistic answer.
I think the point at which you reach the point of diminishing returns is not limited or even totally detemined by your equipment purchases.
I think you have to take a more holistic view espeically focussing on the miriad of demoestic envirnonments.
There gets to a point in every system where no further imprevement can be made in that environement.
The sad fact has to be faced that most domestic envirnoments, especially in newer open plan designs, reach a brick wall as far as improving sound quality. That point is all over the map.
So I have come to realize that every room/environment has a point where no sinifcant improvement can be made. So in other words the only route to further improvement is a total design approach.
So you porbably have realized that I have been fortunate enought to have the opportunity to take a total desing approach. This is not an opportunity that will come to many.
So with this move, I had a complete blank canvas so to speak. So I could build a very rigid house of concrete. I could set the room dimensions to be optiamal. This is an unusual luxury. I could make all walls very rigid. Even small amount of vibration are a big enemy. All wall, floor and ceiling cavities have been highly damped.
The total design extended to the gorund plane of the whole house, Internet and cable installation, and also aspects of the wiring of lights and especially dimmers.
Now most of the equipment is essentially the same. However the results by listening AND measurement have been highly significant. So diminishing returns by no means applied here. So much so that the audiory effects of the room seem to be by no means dominant, which is highly unusual.
I think there are now a variety of speakers and amps that can probably optimize the performance of many listening rooms, so that the benefit of improved equipment could only be realized by a different or improved environment.
As you know as part of this design there are a number of novel features to the speaker sytem which also play their part. What I'm getting at here is that there does seem to ba a lack of inovation in speaker design. What I mean by this is that speaker design has come to be dominated by fashion and ritual far too much, with incresing price not really being a good reflection of R & D and inovative design in most cases.
