Speed drops from 147mbps to 6 mbps when I take it to another room

I bought a WD Livewire last week and hooked it up on Saturday.  My DSL modem and one Livewire unit are at one end of the house and the other livewire unit was about 80 feet away in another room.  The Livewire utility showed the connection for the remote until was at 5-6 mbps and when I hooked up a laptop at the remote end Speed test only got about 120k.  I moved the remote end unit to an outlet in the same room as the primary and the Livewire utility showed 147mbps, so I believe it was set up correctly.  However, plugging it in one room away the Livewire utility showed speeds of only 9-10 mbps. 

Is there anything I can do to improve the speed to other rooms or is this just not going to work with my wiring?

You could try plugging it into different outlets.   Also make sure you’re not using plug strips.  

I’m not using power strips.  I’ve tried a couple of outlets in the same room as the primary unit and get over 140mbps at each one.  But at any outlet in any other room it drops below 10 mbps, and where I really need it I can’t get more than 5 or 6.  I’m tempted to move my DSL modem to a room in the middle of the house and see if that works, but was hoping for a simpler solution.

How old is the wiring in your location?

If it’s fairly new, it may be making use of Arc-fault circult breakers, which, depending on the type, can seriously impact HomePlug AV signals.