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?

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
make sure they is in phase
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,

Thanks everybody for your responses.  I have been trying varying the cables between various components and no difference.  The last one I will try are the speaker cables to amp connections (I'm bi-amping so there are 2 pairs per side).  If there is still no difference it is definitely the speakers.

There is a return period for them, but want to avoid it unless it's something that is likely to deteriorate over time.  I'd like to enjoy these speakers for the next 10-20 years time frame at least.