Modulation something to dull

The microphone fits perfectly with UV-5R and is well made. Only the modulation is described by the received stations as "somewhat dull" but still understandable.
Even the speakers are connected when playing something the heights, but here is the clarity (in reasonably quiet surroundings) nor given well. In a noisy environment, however, this is likely to be more difficult for it then lends itself to the use of the built-in jack for earphones.