เมืองไทยน่าจะมีใครรับทำบ้างนะครับ
http://www.head-fi.org/forums/showthread.php?p=2772352&highlight=pks#post2772352
"The earpieces improves PK2 a lot. With the earpiece PK2s are Shure-like sound, very very nice. Bass is improved and there is much more detail at mid range. When PK1s working with those earpiece, there are more details than PK2(with earpiece). For PK1, the bass part is a little too much, but this problem can be solved by adding resistors and controlling the length of the in-ear-tube. After I connect 75ohm ER4P-4S adaptor to those custom-IEM-PK1s, booming bass vanished. Sound become balance, neat, smooth and detail."
http://www.customearsets.com/