Has anyone tried the ER4S with the JDS Labs C5's bass boost before? It sounds great to me. It's great since the bass boost of the C5 has a centre frequency of 20Hz and pretty much focuses on the sub-bass. Also, the 6.5 dB boost as 20Hz pretty much flattens frequency response at the sub-bass area while slightly raising the upper bass frequencies (300Hz) by a 1dB or less. What do you guys who have tried it before think?
I have many times. With the er4s properly fit deep and sealed I find the 6.5 db is excellent for the sub bass, but the rest of the boost, although still much better sounding than most earphones, affects the mid range too much. It results in a very warm sounding er4s overall and takes away that very clinical (in a good way) precise treble. Also, it is centered more around 80hz, so depending on the music, some songs can sound too bassy with the boost. Things like electronic sound exaggerated. All in all it's still very good. But half the amount or a lower cutoff point would be better. It's better used for movies and tv in my opinion where it doesn't affect transparency as much.