Power Cable Suggestions Needed

You might look at the Zavfino cables.  I find that they have a good grip on the bass.

@brylandgoodman - I have owned several different Harbeth speakers, although not the 7's and, like you, I do not have a lot of room for speaker repositioning.  However, contrary to what they say on the Harbeth forum, I have found all the Harbeths I have owned have been very sensitive to speaker stands and the interface between the stand and the speakers.  I would say the most important think is that using Blu-tak or a soft interface makes them more bass-heavy and possibly muddy.  In bright rooms, this may be the solution for some.  But with your issue, I think you should try some type of hard interface under the speakers.  I have used spikes and casino chips, which both worked to clean up the sound.  The only issue is if you have kids or pets that could knock the speakers over, you need a more secure mounting.  The other thing I found with my old SHL5s, which had dual binding posts.  Using Audience jumpers cleaned up the bottom end considerably, so you might consider that as well.  IMO, Harbeths do work best with those rigid metal stands.  I used to use the Epos I think it was ST-15, but you can't get them anymore.  I guess a different power cord might do it, but I would try the casino chips or something like that first.  Costs you nothing. 

If you are into DIY then I would suggest checking out the Furutech video of power cable assembly on the Audio Union website. I operate Audio Union.

I had several Cullen PCs, well made, BUT...

I have a couple WireWorld Electra 7s that Im no longer using (MSRP @ $240), I haven't listed them, but Im sure we can work something out if interested

Cullen or nordost blue or purple. I’m a shunyata fan, so it you like them and can pushed the limits to an alpha an sigma…..wow. Substantial difference than the venom. Just saying.