Location of compoments.

I just have the amp sitting near the floor between the speakers connected to my gear on the side with the XLR inputs and 7ft speaker cables connecting the speakers

He notes that, if possible, do not locate your audio rack between the speakers, better off to one side. 

And if your components are not in a rack, if one doesn't own a "rack", then what? 

I have never understood the issue of having the equipment rack between the speakers.  It is generally placed back of the speaker plane. Stereo imagine after-all is an illusion created by our brain, based on how the vibrations coming from the left and right speakers are hitting our ears.  There is no "center speaker".  Sound-stage is created by the mixing on the recording.  Unless your equipment rack is placed in the path of the music being sent out of your speakers, can it truly make much of a difference.  And I say "much" as sound waves do not move in a straight linear path, and there could be some reflection off the rack.  But being able to "hear the shape of the rack", and in most rooms, could we really hear the difference?  Moving your own rack would be the only true test, but I personally have not heard a noticeable improvement in my system when moving the rack to the side.  

Not worth it. Get better cables and components and keep it where it is rather than spend more money on a longer version of the cables you are using now. Also it’s best to go with longer balanced cables to amp and keep sp cables short. 

Mono tube amps next to speakers with short runs of speaker cable. XLR interconnects from output of line stage, which are long, equipment on sidewall.