To say that the transducer is the most influential or important part of the audio chain is ridiculous... In order to achieve any where near the the maximum sound quality available the source is the most important. Then the amplification and transducer can be brought up to the same standard to achieve the pinnacle in sound quality.. ie, when the IEM or Headphone is of equal quality to the source you will achieve the best balance. It is stupid to think that your high quality headphones or IEMs can sound their best when fed a sub par signal.
Yup, garbage in garbage out. The best amps and speakers will only show clearly how lousy your source is.