Originally Posted by gnarlsagan
Can anyone give a brief rundown of the differences between the P, S, and B series? I read the blurb on the etymotic site but it isn't very specific.
The P series is boosted a lot in the highs and lows. Is this a large difference from the S series? How does it affect the sound signature?
The S series is designed to compensate for high frequency emphasis in all CD recordings. Do rips of CD's retain this high frequency emphasis? I though CD's stopped using emphasis years ago.
What's up with the B series? How does it differ in frequency response from the other two?
I hope these questions are relevant enough for this thread. I believe they are.
B is the original ER4. At the time, we didn't have any other variants and ER4B was 'ER4'. The original ER4(B) is designed not for modern music with stereo recording (remember, that was 20+ years ago), but for binaural recording which was considered better for headphone listening (still is, actually). The 'pod' on the cable has a small circuit of resistors and capacitors to tune the sound.
S is the 2nd irritation of ER4, where the capacitor in the pod was removed to retune the sound. This is due to the popular demand where people find ER4(B) being a bit too bright for stereo recording (binaural recording tends to sound slightly darker, so the B is tuned to compensate it). So ER4 was made into two versions, B for Binaural recording and S for Stereo recording. Since both still have the same inline resistors, they have the same high impedance.
P comes much later to the game, in the age of CD player and iPod. Since these sources often can't drive the 100+ ohm ER4B and ER4S with loud enough volume, Etymotic decide to lower the resistors value (to 27ohm), but doing so compromised the overall accuracy because the FR curve has deviated much more from the 'ideal curve' than ER4B and ER4S.Edited by ClieOS - 8/8/12 at 7:50pm