Hmm. maybe not too low.   20 dB means the cartridge is now seeing approximately 70 ohms.  Is it written anywhere what the source impedance of the EMT actually is?

when you say that the load was 5K with the WAD, was that the value of just the resistor used or the combination of whatever resistor you were using in parallel with the 47K mm input?

Obviously you've arrived at 8.2K somehow. How do you describe the effect of raising or lowering the load resistor value from the 8.2K you have now, both on the bass and on the overall balance?