Senn HD800 Ultimate, "S" Mod
May 5, 2018 at 11:56 AM Thread Starter Post #1 of 59


Headphoneus Supremus
Oct 15, 2010
This is an HD800 to an 800S mod, not a SDR mod.
It is made more improved over all past mods,
plus secrets learned along the way.

just called it the Ult "S" mod.
Call it whatever you like.

I will post the performance evidence first,
then followed by the procedures, and discoveries made alone the way...

HD800 to an HD800S mod:

Here is a initial comparison to an SDR mod, to show the difference in more upper FR (air), and more lows:


Stock also has more elevation than SDR, above 10khz.
This is why many internal mods affect the ambiance of the soundstage.

Both mods were previously impossible to have without the 6k ringing(diffuse sound), but while both FR changes are good, this mod goes further to eliminate the "diffuse" nature.

More differences:
30db down.

Notice that all decay is faster than .5ms (!),
all way down to 1k..
No 6kringing like stock and even 800S...
Clean CSD, unmatched by any HD800 or HD800S elsewhere (in regards to FR & decay).

Here is a screenshot of the best fabled never released annax mod:

At 50db down a slight 1-2ms decay in trebles, (arguably the cleanest ever made)

Now here is mine 50db down:

(click to expand as looks too big to post large)
At a deep 50db down,
Fast decay of .05-1ms in WHOLE trebles range!
This is proof of no ringing(!)
This is unmatced by any modded HD800, or HD800S... ever before...

Here is a plain stock HD800, with actual ringing around 2.5k area, in CSD at 47db down. You can see the ripple peaks:
hd800 47db dwn.PNG

Here is this "Ult S" mod with zero ripples at same area, same 47db down:
HD800 Ult 47db dwn.PNG


Notice that the harmonics below noise floor,
And also to see is unique is the horizontal linearity of the harmonics.

In this one, the ambient noise was too high, so the white line (THD) reflects that,
and I removed the bass as debatable points because of the noise, but it was a gradual incline with the bass.
So the Bass measurements were too skewed because of the dam ambient noise so I will try update in future post.

One important point to note to make,
is that no other HD800 has ever had a linear distortion (no spike) in the trebles range,
and also stay below the noise floor... ever..(that I know )..
This is unmatched by any modded HD800, or HD800S.

Hear is my Impulse response:

First, It should be noted that this impulse, being the HD800, should be viewed already as a notably clean and noise free impulse response..
Small signal wiggles before the main peak, would reveals system distortion,
of which there are none here.

The main signal is the large first peak.
*There is Less negative overshoot than an 800 or 800S.
*The lack of a strong second upward spike after the initial transient is very important,
and is less than other HD800 or 800S...
This is said to indicates a more coherent sound, and superior imaging.

*The tighter rise & fall of the lines being tighter to the red line ( in this Mod), compared to stock,
is also indicative to cleaner response.
All below the 20 mark is already very good, especially if before 500ms.

*The smaller signals after the initial up and downward spikes,
are the ringing/reflection amplitudes of the enclosure,
of which is also better than any HD800 or HD800S.

*Suffice to say this Impulse response as a whole, is also unmatched, by any modded HD800, or HD800S.

About this mod:
There was no mod available, to make an HD800 sound similar, (but better) to an 800S...
So this was the goal... As you can see by my performance measure.

No other HD800 or HD800S has this level of performance...

Add to that, To also have the hallmark Sennheiser trebles and better bass than the 800S...

This mod WILL give you the bass, without the added blurry harmonics of the 800S(!).

This mod WILL preserve the treble "air" and signature Senn trebles, that other mods either kill off(rug liners & creatology foams) ..

This mod NOT intended to replace the neutral "Super Dupont" mod,
which flattens and evens out the trebles...In order to also lessen the 6k resonance.

This mod CAN be partially applied to FURTHER REDUCE riging in the "Super Dupont" mod..
Essentially making it superior to the fabled never released specs of the annax mod.

This is the only mod that eliminates the resonance problem WITHOUT killing, or neutralizing the trebles...

This is an all unique mod comprising of nobody else tweaks, liners, etc..
It was a year long project that me and another member @ Olegausa finished about over a year ago,
so is about high time it gets revealed.
The upgrades revealed here will be up to the user
next posts coming soon...

Some more measurements...

Comparisons of this mod to another HD800SD with StephanAudio hardwired:

This is a "clarity" tab in REW showing a graph visual representation.
This mod is on right side.

This is the "distortion" tab in REW showing the red line (2nd harmonic) distortion go up around treble region, which is one indicator of the HD800 treble resonance this mod solves...
Notice this mod on right side devoid of such elevated distortion.

This is the "Filtered IR" tab in REW.
Here we see in numerical value, the "clarity C50 & C80" results.
As you can see, the C80 measurement is the one to look at.

On a plain or SDR moded HD800, expect to see 19-20 or lower.

This mod's "C80 clarity" at 56, is more than double of the original HD800, even with a center driver mod like SDR.

I don't expect these numbers to be beaten by any HD800, anywhere...
Hopefully someone in future will "carry the torch" and achieve more?
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May 5, 2018 at 11:56 AM Post #2 of 59


Headphoneus Supremus
Oct 15, 2010
im on lunch...

Ok ready?


AND MAY BE DIFFICULT FOR YOU TO REVERT, AND POSSIBLY DAMAGE YOUR HD800 IF NOT DONE CORRECTLY ...( if your a klux, which your not, and even if you were that wont stop you, right?)



This mod will retain and preserve "presence" and treble air without fatigue,
as the resonance is Eliminated!!!
All while the upper trebles range is preserved without the inherent dips of the 800 or 800S.

Once completed, you will now have now a more focused solid sound with more full and palpable bass(!) Than either stock 800 or 800S..

This is THE ONLY Ultimate 800"S" mod in existence.

Upon completion,
You will now have the deepest and best quality HD800 bass.

You will have most lazer sharp imaging sounding of any the HD800 mods.

It WILL NOT kill Soundstage(!)...
Thats the big pink elephant in the room,
That many deny,
in their quest for a flatter frequency response...

Specifically, many other HD800 mods( by the inherent usage of special rug liners, fillers, or other materials)...

They all work by covering up or filling up the inside(!),
so they all have the side effect of killing the spaciousness and soundstaging,
Which is the hallmark of the HD800.
This approach, is more accurately described,
as "absorbtion".

After trying those other "great" methods, I was unsatisfied after initial joy of ""treble peak" loss,
As I found the signature overall sonically dead and not as lively, in all moded 800 versions..

This forced me to chose another path.
Instead of absorbtion, we go to the root of the resonance problem,
to stop it with dampening, not absorbtion.
Sound damping, and sound absorbtion are two very very different things.

That way, we preserve more of the HD800 Soundstage, by keeping interior dimensions untouched and spacious,
and also keeping the upper frequency range preserved,
which is responsible for treble "presence" and "air"...

It is also already proven (in another site), that the HD800 driver Frequency Response is actually smooth, when tested apart from its enclosure.

This aludes to the obvious problem of the enclosure.
A problem that STILL has not been adressed.
So the solution was damping.
Just like the HD650 was later proven(in another site) to improve with dampening.

Due to the complexity of the HD800 design, it was never considered or accomplished successfully untill now..


List of all modifications:

Sonic Mods:

specific material to slow down the bass pressure from escaping pads
sub-bass seal and Impact preservation, inserted to the inside of ear pads.

*2-rear grill Anti-reflection mod,
This is accomplished by using specific deflective material by grill.
Yes those mesh metal screens in rear affect sound,
but you don't have to take them off (idiot approach).
No grill removal is necessary, as other mods, and this solves listener fatique from rear reflections.

*3- Rear dampening Anti-resonance mod.
(done after first 2)
This is a specific resonance killing material,
on specific areas in back of driver.***
Not any will do!

*4- Metal ring replacement Mod.
(Done Only after 1-3).
The driver edge metal ring is removed and replacement with a vibration damping ring and felt cover.
The problem in the past was that it was not thought out, and done alone...
Done alone solves nothing, just like trying to clap with one hand.
You need equal and opposing mass, which is the Anti-Resonance Mod.

*5- The 800"S" Resonator Mod.
This is a hot item, get it while still in production.

Before "you-know-who" hears about it, and discontinues it!

Supplemental Mods:
*6- Internal wiring replacement mod.
Replacement here is like a magnifying glass effect.
Care must be taken in replacement wire selection,
as this WILL affect the headphone signature tonality,
from sweet to dark, but not in a FR way. In a cable sense way.

My advice is to NEVER replace, unless you're sure.
This is an HD800 modding secret unknown before.
That the internal wire has both an actual resistance and sonic aspect.
Stock internal wiring preserve sweeter sense, so recommendations at end.

*7-installation of mini XLR connectors..


One more note before Mods:
IMHO the SD mod insertion, is the most neutral version.
It is actually the most Excellent for neutrality.

Compared to this "S" mod, the SD mod is a more tame (less lively) sound.

So Mod number 5, is for those that prefer the 800S type signature,
for a more " full ",lively or engaging sound.

For those that like their more linear "SD" Mod signature,
you can still implement all other mods listed here,
to elevate your SD mod to a clearer, higher level.
As the "SD" mod only adresses the Frequency Response signature (6k & trebles elevation).

Actuall Mods Next..
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May 5, 2018 at 11:57 AM Post #3 of 59


Headphoneus Supremus
Oct 15, 2010
Now onto the Mods:

Sonic Mods:
*1-subbass mod.
*2-rear grill anti-reflection mod,
using micro liner by grill
*3- Rear dampening Anti-resonance mod.
(do after 2)
*4- Metal ring replacement Mod.
(Do Only after 1-3).
*5- The 800"S" Resonator Mod.

Supplemental Mods:
*6- Internal wiring replacement mod.
*7--installation of mini XLR connectors.

These mods not for the faint-hearted.
Try at your own risk and it helps if your have some competence in modding and patience.


This whole pad mod has been updated, to instead, to using the Dekoni ferenstrated lambskin pads, combined with a Specific silicone seal, extracted from a cheaper but nice non-senheiser replacement pad, which is mentioned further in the thread.
Here is pic of the required silicone (plastic) seal:

So continue to the below method, only if you are using stock pads:

1- First off,
is the "BASS Pressure/COUPLING SEAL" MOD
Take about an 8" long & 1" wide "rubber tape", and fold in half.


Insert into pads, working your way around the inside,
keeping the rubber flat,
without crushing the tape into a roll:




Sonic results are an increase in the bass "seal", providing a more palpable presence of the subsonics, not noted in measurements, and so the air pressure/ bass feel of impact escapes less thru the foam pads.

This mod is easily reversable.
The tape has no adhesive, and only sticks to itself when folded in two,
Which matches the with of interior pad flap.

When tucked nicely inside, it gives a gentle lift to the pads.
It prevents the older pads "sag" & collapse, and keeps the "new pad" feel and lift, for better soundStage as well.

Once settled they feel normal.
It gives a more solid coupling to face,
so less bass impact is dissapated out of the cloth pads.

Next steps involve pulling off the pads and opening unit, which is why we did this one first.


Next mods involve the dismantle of the unit, and while not hard at all, still I will assume you already know how to do this.
Pull off pads,
Unscrew the ring but be careful as the rear plastic assembly will come off,
so hold unit together and gently remove plastic rear which house the rear grill.
Carfully slide out rear grill & plastic while holding driver unit to its base.

You will be using a micro sized "shelf liner" by the grill.
It is easily attainable at stores.
Cut shapes of thin shelf liner

Insert by grill and leave rear of unit open for next mod...
Make sure the "liner" looks like this:

This will erradicate listening fatigue due to reflection of Upper frequencies.

This is both absorbtion and but more fine knit for dispertion (instead of the metal reflection) without killing soundstage and clearing depth.
This is suggested also to improve all 800 mods.


3rd- the Rear Dampening, Anti-resonance mod:
This most important mod will require the most skill and competence, or just patience.
This is THE mod to improve the SD mod as well.

The specific choice and layout of materials is very important.
We will be using Only

Do not use normal dynamat, or other brands, which are noted to be thinner.
Do not believe claims of better materials either, as that is not key.

We specifically need the thickest possible, for a specific reason which is "mass loading".

The objective here is to "mass load" the rear area of the driver coupling to the basket...
This application of the physical vibrational control of the structure, which will shift and eliminate the structure's resonance problem.

This is not "absorbtion" of existing sound. This is vibration attenuation thru deadening AND Mass loading.
This is accomplished with use on both sides of driver, sandwhiched with both rear and front mod next mod 4.
Changes to the mass loading affects the vibration of the structure,
and thus the resonant frequency of the structure vibration.
That means the shift & elimination of the resonant frequency is a measure of the density of the structure.

Killing structural resonance will control the problem itself,
rather than to bandage it up thru sound "absorbtion",
like the existing HD800 mods of past.

First, we get some specifically cut pieces of DYNAMAT EXTREME!
Make sure it is "Extreme" version, and keep the silver on the outside.
The silver part of this material is necessary for "vibration attenuation" thru change of layer density(usage of different layers).


The basket frame is generally a difficult area to dampen,
So here are the specific locations (critical) for this mod:
Don't waste your time to do this halfway, or by using another material, or another location.

First off,
At The Back of driver inside area,
apply dynamat extreme in these sections:


Once done, set aside and position rear grill mod2 over it, to get ready for closing with next mod...


4- Driver side damping, ring mod.
We replace the metal ring with a same shape ring using dynamat extreme (!):

The ring was nothing more than a "washer" used to hold the driver in place.
It was an obstruction to access the area needed to dampen the souce of vibration to the structure.

This DYNAMAT ring is of an equal location and position, of the rear Dynamat location on other side,
for driver damping on both yet opposite opposite sides of the driver.

This is the specific methodology used, to dampen resonance, and stop the 6k ringing...

This ring is integral to, and is the missing link to the puzzle that was needed for optimal vibration reduction...

Control on BOTH sides to neutralize the structure,
NOT ONE SIDE, as done with past metal ring mods...
You cant clap your hands with one hand right?
You need two..
Same rules apply when dealing with forces (vibrations).
Doing this ring only mod is alone, without rear mod, does NOT work (like clapping with one hand),
and metal ring removal is nothing more than placibo without the DYNAMAT EXTREME on BOTH SIDES.

What should also be noted, is the angle of the damping. Physics for results.
The smaller back-side center of dynamat "ring" shape, combined with the larger frontal dynamat "ring" shape, are is a position to be in a linear line to the basket angle..

This resulting positional "angle" is both the purpose, and what makes it effective to dampen the basket..
A Specific choice rather than over doing "blindly" or excessively damping the headphone with dynamat.


All previous mods must be done and position in place before placing these sticky rings on.

Once front is covered, you won't be able to find the screw hole!

No problem,
just shine a light from the backside, and see how the four screw holes line up exactly with the frame:

*pic* later as its on my phone.

So you wont miss any hole location when putting screw back thru dynamat...
You WILL NEED to use RUBBER CUT pieces, for washers to hold driver in secured,
And for the long screws that need the washer depth.
Then cover the silver side with any color choice of adhesive felt, for looks:

There you go... done.
As you see, I tried both flelt and creatology strips over the ring.

The felt is more neutral and way to go.
While the creatology strips as they suck up sound a bit.
Using felt first, is suggested.

This mods which increase focus, is a bit of a "double edged sword"...

Because the stock HD800 relied on some "euphoric" diffused trebles to extend a bit of false "soundstage air" to an extent..

So with increased focus, layering & separation,
comes less of the extended false diffused air type soundstaging, and replaces with more depth and accuracy,
For a noticably more palpable and greater experience.

This whole mod is also reversable if ever need.
Only messy, as you would have to clean up the dynamat.

I highly doubt anyone would want to reverse this mod after listening to the lazer pinpoint imaging and clearer textures though...

All mods up to this point can be used on "SD" modded headphones.

**** **** ****

5- The 800 "S" resonator mod:

Another unkown topic, is about the center hole.
Why a center hole?
Why not just cover it up?
Because it will sound closed..(!)

While true, the resonator in the 800S brings more lower spectrum, it is (in my opinion, from my research) was originally intended to be a relief of the internal air chamber pressure (where your ear is).

Placing a "resonator" there covers the excape of pressure, so it mutes low level transients, because the driver membrane is thin.

This effect is most notable in the 820, but only with side by side comparison with the 800.

On the 800S, the effect leads to more distortion, or a "fullness" in lower spectrum, along with greater bass from less escaping air pressure...
So there was a balance to strike, and the 800S was the result. Very nice change, but not as "clean" sounding as the original.

This part of mod will give a very similar sonic character and signature of an HD800S.(!)
Use ONLY these specific Sennheiser "ear-tips"!


Make sure the serial number is same.
No other material will do.

Cut the rounded edges off,
to necessary depth (of an SDmod), and then Insert these tips :

Easyest part of the mod.
Install same as you would an SD mod.
Please refer to the SD thread for installation.
Here is pic with SD on left, and "S" mod on right:

Get them, fresh from DIRECT SOURCE.

OR these other sources, while you still can..

So if the Main source dries up, Look here also:





Wait, What?
Want more trouble?
Look below:


Optional Mods:

Replacement of micro stock wiring CAN give you positive results, "IF" done wisely.

That means replacement with known good sounding wire...

Lets take a look at the super tiny size of this wire(!)
*Pic* ( update later)

OMG broken pin,
And 100 AWG! (kiddn)
It is neither OCC, nor good enough guage.
It will ALWASY present an "impedance" to your system...
And I mean that LITERALLY! !

0.1 OHM RESISTANCE MEASURED ON EACH wire, not including connectors !!!

While that amount may seem small, it does matter here.

From my testing, not only the wiring, but BOTH the wire AND the stock connectors are influencing the HD800 drivers..

Remember, we are dealing with on of the most resolving dynamic driver currently,
So everything makes a difference when you're dealing with the HD800 and why cable changes can be heard with the 800.

The easiest and best suggestion would be to install cable hardwired into driver and eliminate the connector...

I did this at first, but the drawback, is missing the option to upgrade to other cables,
So instead I choose the mini XLR sockets in step 7.

At this point, I can only recomend OCC stranded wire ..
Stock wire was thin for a reason.

Choosing here, makes the difference between sweet or dark "qualities" in the headphone.
Qualities that pertain to cable preferences.
If you ever thought wires make a difference,
At this location magnifys it.

This is my recommendation of only wire to use:
Neotech Stranded AG/GD in PE 24ga:
Neotech AG/GD-24 is a stranded, 99% UP-OCC Silver & 1% Gold chassis wire in a clear PE jacket.
The reason for this wire, and at that gauge mentioned, is that it was the perfect size, and it preserved a similar original qualities of sparkling clarity and resolve, while keeping the main advantage that most re-wiring does, which is a more powerful low end.
Also, the choice of solder.
I used to use normal solder.
I noticed a much better flow and work with Cardas solder.
It was superior.
But now I have switched to
The "Mundorf MSolder SUPREME Solder Silver/Gold"
It was to match the consistency of the silver/gold wire.
I am sure there are other choices, but I will only recommend what I know works.
Better than stock wire, and better than the silver plated wire tried, and better than larger guage wire tried.

Ok ,
so now the problem lies in soldering on the connector side.

It is a fragile piece on inside soldering points, and is a sonic "choke point".

YOU MUST have the steady hands of a surgeon to complete this task,
Or you could be out of commission with a broken socket! (On wiring end).

It's like Sennheiser just put it in there to show off and say,
"look at me, I can make a super slick super tiny iem guage connector!"

It really is that fragile inside...
Pic*later of broken internal pin.
Lucky I had extra stock connector.

I found the best way was to UNsolder wires from the driver post first,
Then remove the connector,
Then cut the wire close to the inside connector tips,
But leaving some wire as it is inserted microscopically and deeply inside.
Then tinning(solder) and reinsert into housing to solder the wires on top.




As stated before, the ideal solution would be to totally discard the stock connector...
It is a POS stupidly designed garbage stock connector.

The bottom line is,
those dam forsaken garbage HD800 connectors, WILL "add" to your sound.

So take out, and boldly drill away a larger hole! !
For a mini XLR connector!
The mini XLR I consider easily MORE transparent .

So It was not an easy thing to do either,
as it had to be drilled a bigger hole,
at a slightly forward angle to fit in.

to get that drill bit in THERE,
As it is so close to the driver soldering posts!


This was a silver plated wire which is NOT recommend.

The end result of mini XLR socket is very slick:

And it actually makes it better when using the hd800,
Because the cable is now very Slightly angled forward and away from you.
Plus the shiny connectors are cool.


Enjoy your Ult mod.
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May 5, 2018 at 12:32 PM Post #4 of 59


Headphoneus Supremus
Oct 15, 2010
After a few discussions, it is clear I must clarify on the importance of the:

From further investigation, Senheiser applied a vibration damping scheme, yet it was only partially done inside bottom of the driver.
There is a sorbothane padding.
Sorbothane works in two scenarios.
Compression, or expansion.

The metal ring is specificly used to apply a very even circular compression onto the driver for the rubber/sorbothane to work.
Unfortunately, the did not "sandwich" the driver with sorbothane on the top, so what you have is a partially dampened driver.
A thin felt was applied to the metal ring to help instead of more sorbothane.
This, to me, was a design compromise, and the reason why my usage of dynamat fully resolves this issue.

So instead of compression with sorbothane, I just use dynamat which is a sloppier alternate but most effective.

To complete the optimal design of the hd800 compression, another circular layer of sorbothane would be needed on top, and then the metal ring.
That would also necessitate the use of bolts for the additional necessary pressure of added piece.
There is a member in another forum who uses and made not the bolt size needed.

It is unknown if completing the compression method would be as effective as the dynamat.
It would be cleaner for sure.

I would have to test that idea in future.

Currently, my dynamat method does not involve additional pressure, so the original screws and grill can be retained..

Onto the dynamat method:

I cannot stress enough to use Dynamat Extreme in the perscribed specific location.
I do not suggest in any way to fill the unit up with any Dynamat in any locations.

This is not guesswork,
So I must give some theory and details now...

Only "Dynamat Extreme" is used, in what is essentially two circle shapes...

The shape of the driver edge to be exact,
and for a specifically good and exact reason.

No guessing and splashing dynamat all over unit, in less important areas.

One in circular mass in front, and essentially one behind.

The idea is to stop the vibrational source area (where driver meets structure) in a specific way...

In order to do so, we place an almost equal and opposing mass in front and behind the driver(!) in the specific locations...

Not in any locations far away, which do not have the similar effect.

Think of the HD800 speaker vibration as a moving car tire.

If you want to stop it (physical energy), you must have brakes, which contact on TWO opposing SIDES to push up against, as you cant stop motion with nothing.

Same effect when you blindly load the rear with plain Dynamat,
you essentially do nothing to ACTUALLY STOP the physical vibration.

You only have one side (rear) with dynamat, boucing rear vibrations out to the front thus be added.

This is like a ball (vibration) hitting a soft "wall" (one side of Dynamat) and bouncing back with a dampened (lesser but still there)force back the front!

So your actually amplifying (or actually thickening with more time delayed vibrations) , by adding (deflecting/bouncing) some rear moving energy (vibrations) to the front!
A total waste of time, and not any solution.

What is needed, is vibration attenuation, not spot mass loading, and random diffusion (bouncing vibrations),
which also introduce more complex vibration patterns to the basket structure..

Think of a bell ringing and only touching the inside (rear) .
It still rings but with different ripples of sound.

That's what happens to a "rear only" half done job with regular Dynamat or other material...

It does not stop, as when pinching both sides of the bell, or cymbal...

Like, (last example) what a car brake does to it's wheel, by the caliper squeezing both sides of the rotor.

So what is done to the front, we need to do similarly to the rear,
To achieve "vibration attenuation".

We are addressing physical vibration damping,
in both the
"horizontal plane", and the angled-plane" of the basket...

If you take notice, the rear is in a smaller circle.

So there is a "line-of-sight "angle" between the inner and outer dynamat rings.

This important, because it is in line with the basket trajectory.

So, three things are at play:
not only is the dynamat on both sides,

but it is also on the inner and outer sides of its donut "ring radiator"

And is in an angled proportion to the angle of the basket...(!)


Physical (not diaphram sonics) Vibration is thus optimally attenuated in the angle of the basket structure...

Because the basket structure, is essentially shaped like a "cone" megaphone, so it would naturally amplify or extend out vibrations from the center (including the driver)..

We want the diaphragm sound dispersion, but NOT the driver vibration to be transmitted to the structure,
because the structure can act similar to like a horn speaker.

So my point is, that although we are finally getting good results with other recent methods, (foam, special materials, Pads
Or even the SDR insert & my "S" insert...)

They ALL are NOT addressing the root of the Problem.

They ALL only work to work to "absorb" the resulting sound.

Its like taking medicine for a cold to stop the symptoms, but adds its own drowsy effects(like transient muting), and is not the actual cure.

Only the Dynamat Extreme, "Anti-resonance Mod" will control the root of the Problem.

It "sandwiches" the driver in the "horizintal & basket-angled planes",
to attenuate the driver initial vibrations,
which would then transmitted along the basket, in a similar way a horn speaker amplify!

This is where we get the diffused exageratted soundstage.

No other part of this mod is more important.

No other solution out there, are "Vibration control".

No vibration metholody before,
has taken into consideration my ideas of damping physical vibration,
Both on the horizontal and angled planes..

None have addressed this area in this way before.
You can't just slap some Dynamat on the unit, and expect results,
Or say there are none.

The lack of it being a "driver problem", was known elswhere for a long time.
The driver was not the cause of the ringing.
Once this was known, others tried structure modification with mixed results.

The real issue here, is that my mod proves that the initial vibration from the driver edge,
gets transformed and skewed (resonance) and added into the the physical sound dispersion characteristics (which are known in horn loaded speaker designs because of cone shape basket).

So although this shape is good for dispertion of the soundfield, this specific structure is also transmitting the driver vibrations into the soundfield, making what is observed as an "added" characteristic of an exaggerated and "diffused" soundfield presence.

Controlling the "initial" vibrations before they get transmitted to the structure is the key .

It should be noted,
that although a conical shape structure is designed to distribute the sound field nicely,
It does not have to add/transmit a diffuse the sound field to the sound, as it is doing.

This mod was replicated on two HD800 already, tested and unbeaten over a year already.
So It is proven to be replicated and solid.
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May 5, 2018 at 2:30 PM Post #6 of 59


Headphoneus Supremus
Oct 15, 2010
Pse carry on, mate. We're listening....
ok I updated second reserved post.
Third reserved post will have the actual mod.
It will have lots of pictures.
It will be uploaded tomorrow regretfully as I must leave work soon no time.
It will be worth the wait.
This mod was replicated on two HD800 already.
So It is proven to be replicated
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May 5, 2018 at 11:31 PM Post #7 of 59


Headphoneus Supremus
Apr 13, 2010
Well Grounded, here and now
I look forward to seeing what you have come up with.

May 6, 2018 at 12:58 AM Post #8 of 59


Headphoneus Supremus
Oct 15, 2010
May 6, 2018 at 2:06 PM Post #9 of 59


Headphoneus Supremus
Oct 15, 2010
I will be updating thread with comparison maeasurements done on same measurement rig against another moded HD800..
It happens to be a very excellent mod which is superior to most.
It is a hybrid mod, a HD800 with SDR MOD and my SUBBASS MOD and have HARDWIRE MOD with Stephan Audio Endrorphen cable...
That guy was on the right path when he mentioned and talked about vibration.

Suffice to say that is a very, very excellent moded HD800...
THIS WILL be an ultimate test and showdown, for my Ultimate Mod.
IT should prove beyond shadow of doubt whether this mod is truley worthy.

The key, is using same measurement rig, on a known proven worthy Moded HD800, to have valid data.
To be honest, using a stock HD800 would have been way too easy...
I must test against the best HD800 mods, in order to prove superiority...


I have completed the test measurements for both headphones.

The tests were justified to show mine better but are long winded,
So I will post that later.

But I was suprised they closer in one specific area.

While the diffuse stage was bad and measurable on the other unit,
The 6k ringing actually was better than expected which I will post.
I feel it is due to the SDR mod.

So I will still need to measure a stock HD800, to see how far the ringing lasts when measured with my coupler..

From my testing the diffuse soundfied is not specific to the 6khz ringing or resonance.
It encompasses all the vibrations from the driver.
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May 8, 2018 at 1:41 PM Post #10 of 59


Headphoneus Supremus
Oct 15, 2010
I have updated second post on the importance of the "Anti-resonance" damping mod.

It must be applied specifically or you can be wasting your time.
So some theory and explanations are given.

That part is the most important for achieving focused, lazer pinpoint accuracy and clarity.
It is what makes other HD800 or HD800 sound blurry and dirty in comparison.

If you think your HD800 already sounds clean, and cant possibly get more resolving...

You will be very surprised and awed,
by jaw-dropping focus and clarity.
Actually, if possible, just Imagine the same sound, minus the diffused soundfield.
May 8, 2018 at 7:58 PM Post #11 of 59


Headphoneus Supremus
Nov 13, 2016
I have updated second post on the importance of the "Anti-resonance" damping mod.

It must be applied specifically or you can be wasting your time.
So some theory and explanations are given.

That part is the most important for achieving focused, lazer pinpoint accuracy and clarity.
It is what makes other HD800 or HD800 sound blurry and dirty in comparison.

If you think your HD800 already sounds clean, and cant possibly get more resolving...

You will be very surprised and awed,
by jaw-dropping focus and clarity.
Actually, if possible, just Imagine the same sound, minus the diffused soundfield.
This is the most extensive mod I've ever seen. You are really sumthin', man.
May 9, 2018 at 10:17 AM Post #13 of 59


Headphoneus Supremus
Oct 15, 2010
Can you elaborate on the rubber tape part? Any specific brand you bought?

Also why does it look wavy in your pictures?
It is a rubber tape that had NO adhesive.
Rubber tape is easily found in the hardware store next to the electrical tape.
It is made to be used by electricians, over electrical tape to create a water tight seal for wiring connections that will get wet.

Anyways, it is a tape that only sticks to itself, which is what we want.
The reason you see a bit of it wavy, is because it had to bend inside.
No big deal.

The tape was folded in two, to match the with of interior pad flap.
It tucked nicely inside and gives a gentle lift to the pads.

It prevents the older pads collapse and keeps the "new pad" feel and lift, for better soundStage as well.

Once settled they feel normal.
It gives a more solid coupling to face so less bass impact is lost out the cloth pads.
I updated a bit info in post.
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May 9, 2018 at 3:21 PM Post #14 of 59


New Head-Fier
Jan 21, 2016
Don't think I'm brave enough to try this but it looks really good. Great work.

out of curiosity, have you tested those ear-tips vs the SD resonator? without the other mods would you rather the eartips or SD?
May 10, 2018 at 9:37 AM Post #15 of 59


Headphoneus Supremus
Oct 15, 2010
Don't think I'm brave enough to try this but it looks really good. Great work.

out of curiosity, have you tested those ear-tips vs the SD resonator? without the other mods would you rather the eartips or SD?
Yes they both perform same function.

The SDR gives the HD800 sound with bit less, balanced trebles,

And the "S" mod gives you closest to 800S signature.

You can do those and be happy with reduced ringing.

The Dynamat mods are for elimination of the diffused aspect in the soundstage, giving you more transients focus.

So yeah the inserts are easiest to do.
Also the subbass mod is easy.
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