I have just bought an old AVR 350 through the Classified Forum. There is a 4db difference between the LS and RS speaker outputs as measured by a Sound Pressure Meter App on my tablet. There is less output on the left channel than on the right. If I change the speakers over from L to R the L channel is still the same lower volume as before so it is not a fault with the speakers. I can compensate for the difference with the Level settings in the setup but is this cause for concern? Is this a common problem and is there a fix?