Here are the first initial and easiest HEK mods,
I call, the rear strips (sissy) mods.

For the HiFiMan HE 1000..
What this mod does:
1-Wake up its laid back midrange...
2-Elevated its foggy micro detailing from obscurity.
3-Give it's trebles more presence..
4-Realize & retrieve it's layered soundstage from the current ghostly imaging.
5-Revive some hidden potential,
like was done to the HD800.
This will be a reversable mod,
With 4 levels of choices, but is a starting example for you to try .
OK so onto the mod...
It needs to be critically placed at the key locations I will post in pic, to avoid tonality or soundstage issues.
So this is done by adding a small strip of damping material in two key locations of the rear of each cup.
You will need two strips per side,
For a total of four strips,
long enough to reach end to end.
Here is a pic in bright colors for examples.
*Pic*
Look ma, orange peels!
Just kiddn, it's creatology foam in orange for illustration purposes.

Reminder, these two strips need be in these exact locations to avoid any tonality issues.
*Pic*
Here is is with felt, my 1st choice of material.
This mod is deceivingly simple,
Yet critically placed for preserving tonality & soundstage.
OK, so now onto the four choices of materials:
*pic*
I have numbered them to note both material and sonic preferences:
1- my first choice, a single layer felt strip.
A detailed, lively and spacious presentation.
2- dual felt strip, for some treble attenuation to make more neutral on brighter units without any other loss.
3- felt with creatology on top.
softens trebles further and also softens upper mids. Maybe most neutral but midrange is not as lively on some units.
4- single creatology strip.
My first mod giving a liquid smooth tonality and most treble attenuation,
but midrange presentation is more intimate than others with a bit less percieved bass.
These are the first initial easy mods and can be combined various materials.
The only "rule" is to place them on the exact row pictured.
Enjoy!
I call, the rear strips (sissy) mods.

For the HiFiMan HE 1000..
What this mod does:
1-Wake up its laid back midrange...
2-Elevated its foggy micro detailing from obscurity.
3-Give it's trebles more presence..
4-Realize & retrieve it's layered soundstage from the current ghostly imaging.
5-Revive some hidden potential,
like was done to the HD800.
This will be a reversable mod,
With 4 levels of choices, but is a starting example for you to try .
OK so onto the mod...
It needs to be critically placed at the key locations I will post in pic, to avoid tonality or soundstage issues.
So this is done by adding a small strip of damping material in two key locations of the rear of each cup.
You will need two strips per side,
For a total of four strips,
long enough to reach end to end.
Here is a pic in bright colors for examples.
*Pic*

Look ma, orange peels!
Just kiddn, it's creatology foam in orange for illustration purposes.

Reminder, these two strips need be in these exact locations to avoid any tonality issues.
*Pic*

Here is is with felt, my 1st choice of material.
This mod is deceivingly simple,
Yet critically placed for preserving tonality & soundstage.
OK, so now onto the four choices of materials:
*pic*

I have numbered them to note both material and sonic preferences:
1- my first choice, a single layer felt strip.
A detailed, lively and spacious presentation.
2- dual felt strip, for some treble attenuation to make more neutral on brighter units without any other loss.
3- felt with creatology on top.
softens trebles further and also softens upper mids. Maybe most neutral but midrange is not as lively on some units.
4- single creatology strip.
My first mod giving a liquid smooth tonality and most treble attenuation,
but midrange presentation is more intimate than others with a bit less percieved bass.
These are the first initial easy mods and can be combined various materials.
The only "rule" is to place them on the exact row pictured.
Enjoy!