It’s important to use accurate speakers that have a flat frequency
response. If your monitors are weak in the bass, you will tend to
boost the bass in the mix until it sounds right over those monitors.
But when that mix is played over speakers with a flatter response, it
will sound too bassy because you boosted the bass on your mixer.
So, using monitors with weak bass results in bassy recordings; using
monitors with exaggerated treble results in dull recordings