@martin-andersen - the answer to your original question...
Hi after spending the last months measuring my room with REW and reading about room acoustic in small rooms.
I began to wonder how we can hear differences in equipment when the frequency respons in most rooms are bad.
IT IS VERY DIFFICULT !!!
So - treat your room to some sound absorbing or deflection panels before you even start with cables of any type. You may also need bass traps
Once room anomalies have been dealt with then you can start with cables. Otherwise the subtleties of cable experimentation will be significantly more difficult to discern and prone to poor choices
BUT WAIT ! - are ALL your components capable of resolving to the same level ???
If not, replace components that you suspect are of a lower resolution
- errrrr - isn’t that a bit rash???...
- YEP !!!, but that is the approach of many audiophiles
However - many of todays lower priced components are very good BUT severely limited by their own power supplies.
This is where the power cables come into play...
After experimenting with several of my "budget" source components
- I ( AND OTHERS) have observed that significantly better performance is attainable simply by upgrading the power cable on budget components.
As an example - I replaced the power cable on my $300 mini system and my Bluesound Pulse Mini remote speaker and achieved a significant improvement in dynamics, image and bass performance.
The Pulse Mini endeavour was a particular "triumph" because it was conducted in the audio store where I purchased it and the resulting improvements were observed by the owner of the store an his staff, who all could not believe such improvements could be attributed to a simple power cable upgrade.
Once you have the treatments and power cables taken care of then you may stand a chance at hearing the more subtle improvements other cables may make in your system.
I liken power cables to the "plumbing" in your home - without great plumbing, what comes out of the tap is only a fraction of what is actually possible.
I will add that components that contain very good power supplies (like amps) will need extremely good power cables in order to hear a similar level of improvement, whereas, a component with a lessor quality power supply and only a reasonably good power cable may be attributed with a more discernable improvement.
Implementing a single model/make of power cable for all components may not be the best way to invest your hard earned money.
So choose your power cables wisely.
Hope that helps - Steve