Senn HD800 Ultimate, "Maxx" Mod
Apr 25, 2022 at 12:05 AM Post #122 of 173
Hey dude, would it be bad or no sound change at all, if I do this?

I only use the best Dekoni Ferenstrated leather pads.
Therfore I do not know if Dekoni uses the same dust cover material.

Here are the issues and conditions that would allow you to consider this:

1-The first issue, is that the human ears keep growing with age, so more space would be appreciated mainly with older people, not young people.
2-The second issue is that there is plenty of room already for the ear, when using the thicker pad selection I use.
3-The third issue is that it is irreversible.
4-The fourth issue is that the material Dekoni uses for the pad I use, is totally audibly transparent.
5- The fifth issue is the choice of using stock dust covers.
These stock covers do alter the sound. They may be preferred on stock unmodded headphones, as they do tame and smooth over some of the top end.
You can keep them in and use them under the Dekoni pads, if you like.

Personally, IMO I choose to never use the stock covers, as I go for maximum clarity, but I can see how it would help with excessive trebles that the stock unit has.
 
Jun 23, 2022 at 7:47 AM Post #123 of 173
Thanks @Maxx134 for the help! Couldn't have it done it without your guidance!
 

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Aug 15, 2022 at 8:34 PM Post #124 of 173
Thanks @Maxx134 for the help! Couldn't have it done it without your guidance!
Here is a "recap" of how to perform this mini XLR socket mod:

I use hot glue inside once I get it in snug, and the very slight angle is unavoidable, but perfect angle when wearing, to position the cable away, not straight.

You will need a special drill bit I will post pics:
Screenshot_20220618-225847_Drive.jpg

Using these two different tools will give you best results..

If you try any other tool, you will risk damaging the driver soldering points inside.

Use the specific "RYOBI" angle drill bit first, with patience and controlled easy pressure. Take your time, no rushing and no excess pressure, in order to go slow.

We use same hole, only expand it larger, and also angle drill slightly downward so that the new socket does not hit the driver. Look closely at pics.

I also marked the "positive" in red. Positive on driver is same pin on both (L&R) sides, so not "mirrored".

Then once hole is achieved, you get a dremel to use that specific dremel tool in picture, to smoothen and widen the hole enough for a snug twist fit of the mini XLR socket.

Then insert the socket, with wires already soldered/attached,
20220322_150937.jpg

to eliminate any soldering in small area, as that would be difficult and messy. Use the image for soldering.
Solder the wires neatly, taking your time.

Finally, check connections work, by plugging in a cable to test, before applying hotglue.
20220322_155806.jpg

Apply very generously, but do not exceed the area-cavity dimensions, to not have it bulge more than space inside,
Screenshot_20220618-231400_Gallery.jpg

or else the outside plastic hd800 parts will be hard to place over it.

There you go. Goodluck to anyone wanting to try this.
 
Aug 15, 2022 at 9:04 PM Post #125 of 173
I haven't updated this thread in a while due to other projects.

Still have to post audio file differences, but today I will post a direct comparison observation.

I have a friend's HD800S, to compare against my HD800M:
20220814_184344.jpg

I haven't had the HD800S to directly listen "side by side" with my latest HD800M in a long time, and doing so, I am still a bit surprised.

Here are my observations:

The 800S unit was more forward, and hitting a wall, with lack of noticable depth and micro dynamics in comparison, which made my 800M unit noticably more layered in comparison.

Then there is the bass difference. I was curious to see how this 800S would hold up, but it wasn't anything like I had expected.

There was a bass, to mid bass in the 800S, which was "masquerading" as the whole low end sound, but in comparison to my 800M, it was a very different experience.

The 800M displayed an actual noticeable and integrated subbass with dynamics* in that region, which made the music track sound very different.

Bottom line, the HD800M was an Impactful and more real low end, where as the 800S, in comparison, had no impact, replaced by a slightly forward compressed mid bass.

To put this in perspective, this is the HD800S, not the HD800, and so I am reminded of the disappointments & frustrations of all iterations to owners.
It is a waste of what is a potentially a true end game headphones with the 800M mod, which Sennheiser should have taken up.

I will now be performing some tests and measurements, to see if I can fix the 800S driver better than the 800"M" driver.
 
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Sep 4, 2022 at 1:54 PM Post #126 of 173
Latest update on HD800S drivers testing and modification came at expense and loss of one driver.
It turns out that even following my latest tools, protocols and procedures, I still managed to damaged a driver.

So my modification procedures lead to a reduced installation failure rate from 75-80% to 50%, so it's still a 50% danger rate (in the transformation process only)which means any future contemplation of moded units would necessitate an extra driver expense.

It is important to state that once achieved, the driver retains all the durability, longevity, and reliability of stock unit, in performance.

Until this issue is more fully resolved, a public disclosure cannot be done, but instead, a recruitment for skilled modders willing to learn. Those interested can PM me.

On the bright side, I finalized the HD800SM mod.
It was a pretty noticeable success.

Ok , so the good news is that I measured and verified an increase 2-3db across the whole lower spectrum, with a boost of 3db at subbass of 13hz, over the HD800S ...not the HD800.

Also, the traditional Sennheiser dip in upper mids had also been reduced, and also slight extended range in the upper trebles beyond 15k.

Will post some pics, video and measurements next.
 
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Sep 4, 2022 at 4:19 PM Post #127 of 173
Ok just did some more measurements...
Turns out my latest HD800SM mod delivers a full 6db bass increase in 15hz-20hz, over the HD800...
The bass improvement continues as almost 3db elevation at 30db. The bass improvement starts at 65hz.

More linear mids from 1-3.5khz aa well, and an extention of trebles of 20-24khz.
Will fill in this post with measurement pics soon.
 
Sep 5, 2022 at 12:08 AM Post #128 of 173
Here are the measurements on the new HD800SM

HD800SM vs HD800:
HD800SM vs HD800-2.PNG


** Full 6db bass increase, from 15hz-20hz, over the HD800...
** Bass improvement continues as about 3db elevation at 30hz..
** Bass improvement reaches to 65hz..
** More linear and elevated mids from 1-3.5khz, eliminating need for tube amps.
** extention of trebles measurement..

~~~~~~~~~


HD800SM vs HD800S:
HD800SM FR2.PNG


** 2-3db boost across the whole lower spectrum ..
** Real boost of 3db of subbass at 13hz ..
** reduced mids dip compared to HD800S ..
** slight extended range in the upper trebles beyond 15khz ..

~~~~~~

It should be noted that all of the headphones above, were measured on the same setup.
My setup, being different as other websites, will have HD800 images a bit different as other measurement setups, which is normal...
It is important to note that every website measurement has a different but similar image.

Mine shows an excessive 4K area dip which would not show same on other setups. This is due to the usage of paper on my measument coupler, instead of any type of foam. This choice was made in order to not have loss of Upper range accuracy, that any type foam does to kill upper spectrum.
My usage of same rig, instead of updating "ears" coupler is due to keeping a same baseline for all my older measurements.


When comparing images with different measurement rigs, they will start to differ somewhat, from 1k to trebles, but bass is always be very much on par with other setups.
So there is accuracy in determination of this latest HD800SM mod to be superior in bass comparison, over the other Sennheiser variants currently available.

S
ince it is not done with any frontal, basket material playing like HD8XX, there is a fundamental difference of performance improvement with HD800SM, compared to only material "tunning" changes like HD800S or latest HD8XX.
The HD800SM takes advantage of NOT altering the frontal implementation of the 800S, which is also included in the 8XX.

**
Edit:
Will upload a 8XX comparison when I get one to test.

I also redid the flat black paint of the 800S stock paint job, to differentiate it. 👍
 
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Sep 5, 2022 at 12:33 AM Post #129 of 173
Video of new HD800SM paint job, done on an HD800S.
Notice no lettering is lost:



In order to get a level of painting close to auto air spray, I used paint from "66autocolor" site. 👍
 
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Sep 10, 2022 at 3:08 AM Post #130 of 173
Will upload a 8XX comparison when I get one to test.
I happened to do a search for HD8XX unboxing, to check how package if sealed, and came across a comparison video.
I was under the assumption that the HD8XX was supposed to have a bass benefit, but upon listening to this video, it turns out that the HD800S actually has a bit more subbass than the HD8XX!

I was shocked to hear this. All this whole time I was believing the effort was made to " improve" bass. So it no longer seems the case. The 8XX is just a variation of an 800S.

I will verify myself, if it has any real bass, instead of others images.
So far this video shows no sub bass improvement at all, which means my HD800SM will have the same substantial bass improvements of over 3db avg, across whole bass area...
So I will verify.
If anyone has an HD8XX to let me test, PM me.
 
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Sep 10, 2022 at 7:41 PM Post #131 of 173
I have decided to look into this, and attain a 8XX, in order to make a true conversion to 800S, and then update it to an HD800SM.
Will post measurements & pics along the way to record this here.
Edit**
After much contemplation, I realize it's too much work and instead will just optimize the 800S drivers, which, after more investigation, I now believe are the most robust version.
 
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Sep 10, 2022 at 10:14 PM Post #132 of 173
So if I buy a HD8XX and lend it to you, then you will do all the mods for free AND even cover the costs for any parts that you break or kill, like the drivers? :wink:
 
Sep 11, 2022 at 1:16 AM Post #133 of 173
So if I buy a HD8XX and lend it to you, then you will do all the mods for free AND even cover the costs for any parts that you break or kill, like the drivers? :wink:
Haha you can lend it to me as the first guinea pig for testing to see what if can be done.
It guaranteed to not be the same 🫣🙃, lol
 
Sep 12, 2022 at 2:09 AM Post #134 of 173
break or kill, like the drivers? :wink:
After much recent investigation and contemplation, I would not replace any broken units with 8XX drivers. It is my determination that the most refined/robust driver version Sennheiser made, was the driver inside the 820 unit, which is the 800S driver.
It's just easier to work with an 800S. The 8XX would just take longer to convert.

I am no longer convinced the 8XX driver is same as an 800S driver (with changes), because of the difference(lack) of subbass from that video.
I do know the original hd800 driver has a bit more clear membrane on the diaphragm over the HD800S, so that would tell me clues if the 8XX version is a hybrid of either.

So I would simply consider the 8XX as another tunning alternative, just as there are users who like the 800, or 800S. Although the main concensus it that the 8XX has a “narrow corridor” effect which can be alleviated with the basket tap removal.
The driver still has the issue of covered holes and unknown driver membrane from either an 800S or an 800. Regardless, it's a variant with similar potential.
 
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Sep 13, 2022 at 11:55 PM Post #135 of 173
I have just refined my modification process and ordered new tools to reduce my latest mod safety margins to estimated 90% instead of 50% or so. Have to wait till parts come in to try another mod. If this works, my modification process can be made public.

I am also still interested in the 8XX driver so hopefully I can look into it.
 
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