Earpad mod for Koss/Massdrop ESP95X. This only works with the Massdrop Velour pads and is 100% reversible to stock in seconds. $5 mod.
There are many earpads made for the Koss. They all affect the sound in different ways. Some of the custom pads are quite expensive, and there's no way of listening before purchase. I wanted to experiment without investing a fortune and wanted to tune the pads to my tastes.
First, I thought about stats and pads. A better seal increases bass response, up to a point. Totally sealing the earcups can reduces bass, dynamics, and soundstage. Bass is probably reduced because there is too much pressure build up inside the cup and the ultra light weight, low power electrostatic panel can't overcome it. Most electrostaic speakers and headphones aren't closed back or in a box. So, first design point is to allow some leakage.
Second, closed back earphones almost always sound closed in compared to open air phones. The close proximity of the pads may cause reflections that muddy staging cues. Earpad reflections need to be controlled.
Third, the pads need to be tuneable and easily returnable to stock. The exact amount of seal and reflection should be adjustable to suit owner's tastes.
THE MOD
Mod uses 5/8" velcro (the part with hooks). Buy the NON STICKY sew on type ( Do not sew). It naturally clings to the velour pads and stays where it is placed. I used 1 10" piece for each earcup. After months of listening I decided to add another 1.5" to each ear cup. You may decide upon a different length. Velcro allows this to be adjusted instantly. Notice that 11.5" is too short to surround the whole earcup. This allows some air leakage for more dynamic bass. Make sure to locate the Velcro right up against where the pads attach to the earcups.
11.5" won't encircle the complete earcup. It makes a difference where the open gap is placed. I placed the reflection prone velcro behind the ear and left the front open. There aren't any high frequency reflections in front of the ears to reduce sound staging cues. Set up properly, the modded phones sound open like the stock Koss. The 1.5" additional Velcro wraps around the bottom front of the pads. This positioning proved quite important to bass quanity and impact. See photo (I hope it works) to show placement of velcro.
I use a PonoPlayer or sometimes Ayre Codex into the Koss energizer with stock power suppy and an ADC Sound Shaper analog EQ. Without changing EQ settings, the sound has more impact and dynamics in the bass with as good if not better sound staging. The Velcro's width is slightly less than the earpad so it won't touch your face. This mod also fixes one small gripe I have with the Koss. It allows correct L & R channel identification by feel, even in the dark. Velcro gap faces front. Hope some of you will try this mod and do a little experimentation. Would love to hear your thoughts.