New power cables, stands, contact enhancers bla bla bla... Lets be fair these all make hardly noticable or no noticable effects.
The biggest improvements You can get by tweaking are right SPEAKER PLACEMENT, ROOM TREATMENT and for mid-hifi and mid-highend speakers try damping speacker cabinets using special absorbing materials. This reduces boomy box sound and resonances, reduses brighntness and adds musicality. But don`t over try otherwise You loose in details and deepness of soundstage. For bright sounding systems is this the cheapest and more effective method to reduce harshness and add warmth.
These twaks all make easily noticable effects while higly expensive cables, stands and other audiophile stuff are hardly noticable.
This is only my opinion basing in my experiences and doesn`t claim for absolute verity.
Happy tweaking
