[Raketen]

Surgical tape is not the best damping product. Acoustic foam would be leagues better. Bubble wrap is also an excellent and better than fiber fill, so are old jeans ie. canvas. Hell, activated carbon kills everything for damping! Activated carbon you say, no way? Crazy right? Not really. Due to its structure crazy microporosity, "just one gram of activated carbon has a surface area in excess of 3,000 m² (32,000 sq ft), as determined by gas adsorption."

http://international.kef.com/explore-kef/kef-innovation/ace

Time to start cracking open spare water filters :veryevil:

 

[TheManko]

Now I'm curious about putting activated carbon in the headphones lol. Had a look, and it's easy to find. Wonder which kind would be most appropriate. It has many common uses, like in kitchen fans, so you can buy sheets and bags of it.

 

[thesmokingman]

Time to start cracking open spare water filters

 
Yea exactly.
 

  Now I'm curious about putting activated carbon in the headphones lol. Had a look, and it's easy to find. Wonder which kind would be most appropriate. It has many common uses, like in kitchen fans, so you can buy sheets and bags of it.

 
You can get a relatively thin sheet of it that should be easy to work with from Amazon. KEF used bags of loose carbon like in their ultra thin 9000 series like the media bags filled with carbon in aquarium filters which is easy to get. I'd assume sheets work too. It's just that in headphones loose carbon might rattle right next to your ears w/o knowing how tight it is packed.
 

 
 
https://smile.amazon.com/Fellowes-CF-300-AP-300PH-Purifier-9372101/dp/B0067D7DEA
 
Ooh, forgot I have some sheets of the above for our Winix filters around here somewhere.

 

[Mark Up]

 Surgical tape is not the best damping product. Acoustic foam would be leagues better. Bubble wrap is also an excellent and better than fiber fill, so are old jeans ie. canvas. Hell, activated carbon kills everything for damping! Activated carbon you say, no way? Crazy right? Not really. Due to its structure crazy microporosity, "just one gram of activated carbon has a surface area in excess of 3,000 m² (32,000 sq ft), as determined by gas adsorption." http://international.kef.com/explore-kef/kef-innovation/ace

That's true. I wonder if a small layer of loose wool or something floating in the back of the cup would further reduce reflections a bit. Bubble Wrap, probably not. It may be good for low end, but the midrange resonance would be unaffected and high mids made worse, perhaps, by the reflective nature of the plastic. That Carbon idea is really an interesting one. KEF does make great products and they know their stuff. Is solid, stable but soft material made of that even available and usable for DIY folks though? I'd think you end up with powder.

 

[thesmokingman]

It was pretty darn easy. Now that I've sacrificed a $10 sheet, I've got enough to make at least 7 other sets.
 
I took some pics, old mod vs new. It took all of 5 minutes or less after making the template.
 
Orig mod with acoustic foam
 

 
Comparison of foam vs carbon, foam is actually a double layer. I peeled the top layer off and left the initial layer inside the webbing.
 

 
Removed top layer, ready for carbon.
 

 
Carbon pressed in, it molds to shape and stays put, thin strips of foam help hold it in place.
 

 
The sound? My first impression is the depth and width of the sound was !@#$ huge. I'd want second sets of ears to hear it. I dunno if its just me and the placebo effect in play, ie it sounds awesome because I want it to sound so. That said, it sounds large and deep, its not just the bass this time. I'm going to spend some hours to get to know these cans again, but thus far there is nothing remotely bad to say about this change up.
 
 
*If anyone wants to try it out, pm me and I can send a pair out snail mail.

 

[TheManko]

I'm going to pick up a $10 sheet of carbon intended for kitchen fans tomorrow. It looks the same as what you put in. So easy to open the Z7, so why not!

 

[Mark Up]

It was pretty darn easy. Now that I've sacrificed a $10 sheet, I've got enough to make at least 7 other sets.

It sounds like you had great results. Can you or anyone share links to this material as far as where I can buy it? Also, is this stuff sturdy, meaning it won't flake or shed dust or something? I know it's hard to tell long term of course. I think it can't hurt for me to put that in with minimal if any glue and try it in.

 

[thesmokingman]

  It sounds like you had great results. Can you or anyone share links to this material as far as where I can buy it? Also, is this stuff sturdy, meaning it won't flake or shed dust or something? I know it's hard to tell long term of course. I think it can't hurt for me to put that in with minimal if any glue and try it in.

 
I used a sheet from our hepa filter. It is tough. You'd have to intentionally crush it down or grind it to break it down further. I saw a six pound bag of AC... I started to think of my acoustic suspension Sony SS-M7 speakers. Hmm, it is funny how the mind works.
 
https://smile.amazon.com/Fellowes-CF-300-AP-300PH-Purifier-9372101/dp/B0067D7DEA

 

[Mark Up]

Thanks for the response. If it is meant to reside in an air filter, I gather it won't turn into powder or shed dust, given its role. I've got some exploring to do.

 

[TheManko]

Given that carbon filters catch filth in the air, will we need to change the sheets in the headphones every 2-5 years or so? They might not turn to powder, but they might become moist.

 

[thesmokingman]

  Given that carbon filters catch filth in the air, will we need to change the sheets in the headphones every 2-5 years or so? They might not turn to powder, but they might become moist.

 
Fwiw you can bake them in the oven to get the moisture out.

 

[TheManko]

   
 
The sound? My first impression is the depth and width of the sound was !@#$ huge. I'd want second sets of ears to hear it. I dunno if its just me and the placebo effect in play, ie it sounds awesome because I want it to sound so. That said, it sounds large and deep, its not just the bass this time. I'm going to spend some hours to get to know these cans again, but thus far there is nothing remotely bad to say about this change up.

You weren't imagining things. I've now modded mine with carbon sheets. Before modding I did some listening to refresh my memory and pick tracks to test. I also left the volume knob on my amp alone so I'd have the exact same volume when I returned with the mod in place.
 
The sound is noticeably cleaner and less congested. The frequency balance sounds the same, except a tad less deep bass. Can't tell if it's just less distortion, or an actual lowering of bass amount. Maybe both? Either way, it's only a bit less, to where I might be able to live with it. There's still physical impact. What's been gained in return is a more open and transparent sound, where layers in music are more clearly separated and easy to focus on. What I'd describe as a higher resolution sound, taking it closer to higher end headphones.
 
The biggest negative with the headphone now is how you can play it ear bleedingly loud without noticing.
 
EDIT: One of the advantages of a tighter sound is the headphones are more genre versatile. Compared to the stock Z7, it's quite remarkable what a difference modding makes. One track I used as reference before I did any modding was Painkiller by Judas Priest. I compared it with my HD 800, and it was obvious how much the congested sound of the stock headphones was concealing. With the surgical tape mod the song cleared up quite a bit, and now with the carbon mod, nothing is missing apart from the upper treble. There are a lot of effects on the vocals, like the voice dissolving with a heavy reverb. With the stock Z7, it was hard to hear these effects, whereas now you'd have to be deaf not to notice them. These are now great headphones for metal.

 

[Mark Up]

I guess the upside is nothing can grow on carbon as far as I know. Mold or bacteria would die (I think) as it would not sustain them (I could be wrong).

 

[jirams]

Has anyone experimented with Blu Tack as a damping agent?

 

[thesmokingman]

  Has anyone experimented with Blu Tack as a damping agent?

 
I would guess that it's fundamentally a rubber based product so it probably has some use as a damper when it comes to vibrations. However that would make it more effective as a structural additive, absorbing vibrations but not necessarily as an acoustic damper. One absorbs physical vibrations whereas the latter slows sound waves down. The right damping material can increase compliance thereby increasing volume. They are both dampers but in different respects. Also there are other ways of using rubber such as making a foam out of it which increases its surface area making it a good acoustic damper.