Responses from hifi78

Remove Radio Station Background Noise
The antenna is likely your tonearm cable, where it loops over top of the arm. Reach out to VPI for their input on solutions.   
REL Subwoofers help
It really depend on your speakers low frequency response in your room. My speaker go flat to about 42Hz and roll of gradually from there. I run the crossover at 30HZ for a stereo pair of S5 SHO. Lower crossover and higher gain is the way to go.  
Diffusion vs. Sound Absorption views
Diffusion actually reduces the strength of reflections off of the front wall, behind the speakers. QDR diffusers placed vertically will reflect out horizontally into the room and most QDR's need at least 6ft between them and the listener to fully ... 
Distance from the front wall for magnepan mg 20.7
Those who believe a sub will ruin imaging have heard the wrong sub or didn't know how to integrate it.  Buy a REL sub or two and you will be blown away.   
Bass trapping - corners or walls?
I have followed the method outlined in the article above and it worked well for controlling bass resonance issues.  Bass traps place in the corners behind my speakers actually resulted in less ambience eventhough the reflectors were aimed into the... 
Balanced Preamp recommendations up to $5,500
I'm very interested in your feedback on the XP12 and XP17 as I have not seen many reviews since they have become available....