To everybody concerned with basic seal, channel imbalance, faulty units etc - the simplest way is to play some pink noise. It can be had online in numerous ways, here
just one : https://archive.org/details/TenMinutesOfWhiteNoisePinkNoiseAndBrownianNoise
You should get a steady "pillar" of sound dead center in your head - anything else is "something wrong". Start with the tips - you may well find that tips you thinkt to be OK actually do not seal *that* well as you thought.
That sound should, above all, sound SMOOTH - if any particular portion of spectrum sticks out, it should be readily apparent. If there are any inbalances, it will be audible instantly.
Regarding both (to me ) known measurements of Havi B3 Pro1 (old version ) - those must have been defective samples. The level of distortion is still very high, but balance issues SHOULD NOT BE THERE. The whole situation did make me apprehensive regarding the purchase of yet another spare pair of B3 Pro1s - if it turns up to be light years removed from SQ of the pair I own, it would just be waste of time.
I wish Havi would tighten up the QC - TT Pod 1(E) are guaranteed to be +- 1dB of within each other, which IS very decent matching, specially for the price. I would prefer Havi B3 Pro1 to be measured and graded, similar to phono cartridges by Grado - the same model of each cartridge from the production line gets tested and graded according to the tolerances; natuarally, mid level costs more than basic, top level more than mid.
Sauggestion $ 40 for the basic, $ 80 for mid and $ 150 for top level - all GUARANTEED.