Vandersteen 3A Signatures with 2 dB difference between L and R Speakers

I just purchased a set of 3A Signatures CPO from a dealer, and was running a frequency sweep using a calibrated mic and it shows a 1.9 dB difference in volume between the L and R speakers.  Is this within the margin of being acceptable?  I thought these speakers came in matched pairs, do they not?

Make sure the adjustments for tweeter and midrange on the rear panel are set the same.  (Sorry if that seems obvious ...)
swap speaker wire L to R , see IF problem changes. Speaker located same place ?Vandy open, call.
locate speakers side by side middle of room, test. Who is the CPO dealer ? have you reached out to them ? 
best to you
i had 3a Sig for many happy years
a slightly less tight connection can effect signal strength/volume. either end of speaker wires. either end of interconnect.

verify all tight, measure, _____?

switch the speakers themselves. measure again ___? if difference moved with the speaker, it's the speaker. If difference remained as it was, it's the equipment/chain.

Another reason to have remote balance control. I won't live without one of these. You need the remote control, it won't work without it.

 a few are available now, sometimes none,