Sennheiser HD650 Love (Appreciation Thread)

Bravo! Not many guys have such guts to snapped off somethin' (at least I don't, but will try in the future, curiosity kills the cats).

 

@Hands, I tried the liner before the foam: http://i.imgur.com/bND9weP.jpg found that too much so I removed it again and this is less thick liner I used for the HD800 tests. I just added some extra Dynamat to the holes: http://imgur.com/a/Dkqtk which I'm not sure did anything but wth it works fine! I have some K240 foam coming in to test in front which seemed to measure better by Solderdude and that's about it.

 

Just had a crazy idea. I have some left over 1mm thick self-adhesive felt (same as I used for a Hifiman "fuzzor" mod). I wonder if putting that on the silver screen with a hole for the driver would help with reflections?

 

A bit too dampened.

Anyhow I decided to follow the full example side the liner... Here she blows: http://imgur.com/a/z491V.

Here's an easy how to for removal of the plastic without it falling in the driver, first simply cut the top piece of plastic at the bottom ends of each footing, this simply removes the big chunk. Then to remove the smaller cuts easily, use small tweezers to pull up the piece of plastic which you can either break immediately or just pull it up and cut it with the wire cutter. Do this while standing up and facing a table or the ground, turn the headphone around to make sure all of it is falling there and not in the driver.


Subjectively: there seems to an extra sense of resolution, which is either caused by the reflective nature of Dynamat or because the bass seems further controlled overall then the original trio of mods. I did some side by side testing by doing one side first and leaving the other side alone and A/Bing with different songs. The differences vs. the original mods aren't day and night, these are minor differences but there's definitely something happening. I like it a lot, thanks @Hands for the idea.

 

Ah that kinda sucks, maybe just get the new ones? Front mods I'll try with the foam of the K240 when it arrives, should give a good idea since it's nearly the same mod.

I think the reflective nature of Dynamat is the reason why there seems to be an added resolution. This was something I noticed when working with Dynamat on my HD800's trapezoid. So on the 650 I actually like it, I think it works wonders.

On a side note, if anyone needs Dynamat I can probably ship a good chunk to any place in the world for about 2,50 euro in shipping. So let me know if anyone is interested.

 

Thanks for the modding tips, and for the continuation of this thread. Love the 650's. My headphones for daily listening for over 4 years... they still blow me away.

 

So my dynamat should be here in a few days, and I know you guys have said its kind of hard to handle. What's the easiest way to cut it? I think I remember someone saying to put it in the fridge or freezer? Does an exacto knife work? Or should I use sharp scissors?

 

I put my dynamat in the freezer for a bit and just cut it with a utility knife with a new blade on cardboard. While the stuff is warm it is much harder to cut the gooey tar middle.

 

My attempt at placing the dynamat around the magnet. I cut a 2cm x 2cm square with scissors and then the circle with a x-acto knife.

 

Holy shit the front roam's itchy! I can handle the firm clamp but when the front foam rubs against my ears it's just so annoying. Dem pads though. So smooth! I could rub my face against those mofos all day long.

EDIT: Nevermind, used a keyboard box to reduce the clamp and can't even feel the front foam anymore. So much more comfortable now! My jaw is thanking me as well.

 

I removed the drawer liner as it was pushing against my ear and causing discomfort for longer listening sessions. 2 plies of TP killed too much treble so 1 ply is the compromise for taking the edge off sibilant tracks (cut down to the outer circle marked on the silver mesh which I think corresponds to the outer edge of the driver). Guess the quarter-mod isn't for me, treble-weaksauce ears that I have. Can't believe I once considered buying the HD800.

I removed the rear foam and found the bass increase to be much more than I was expecting from descriptions here, and to be rather bloomy/bloaty as well. Didn't like it. Putting the foam back in to the original state as-is is pretty much impossible, as there no way you're going to pull it into the tiny slots under the plastic ridges. I dug up some aftermarket K7XX foam donuts that are roughly the same "porosity" about 2/3 the thickness of the original rear foam. I cut them to the "lozenge" shaped space inside the plastic cage and could easily get them into place. I was hoping for something halfway between "stock" and "no foam", but they sounded pretty much stock as far as bass was concerned. I then cut a roughly 3mm diameter fart hole in the foam, basically a mini "quarter-mod" for the rear*. This gave an increase in bass response from mid down to sub just going by ear, while maintaining control of the bass. I like this very much so far.

Photos: http://imgur.com/a/shNiW

I received my Dynamat from @philipmorgan today (Thanks!) and was surprised at how thin it is. Some of you may be surprised by how thick my blu-tack is. I assumed that Dynamat would have much better damping properties so I stuck on as much tack as possible to compensate. Does anyone know if the damping effect comes predominantly from the mass of the "tar" or from having the aluminum backing on the tar? Has anyone doubled up applying Dynamat (i.e. 2 layers)?

*Edit: I'm calling this the "Life Saver mod".

 

I can certainly relate. I also tried to put back the foam behind the driver but figured that without pulling it into the ridges, the foam could get stuck or even go deep into the hole and get stuck within the driver so I ended up breaking off the ring altogether. It was pretty easy as well since the plastic is fairly flexible and didn't break into small pieces when I yanked it off

 

I used dynamat in car audio in the early 2000's, back then people used to dynamat their whole interiors. The idea was to dampen sound waves bouncing off from the metal interior. In home building we are often asked to dampen sound between bedrooms, offices, between floors, etc. Acoustic islotion dampers, acoutical lead rolls, and rock wool insulation are commonly used to reduce the mechanical vibrations between spaces.

To absorb excess vibrations or mass load the rear of the driver, the black "tar" is absorbing the vibration. Double layers or thicker blue tack may have additional improvements, but I am not sure if additional mass loading is needed. The measurements of the single layer didn't necessarily show up on purrins first attempt. More layers could also have negative effects, would be interesting to measure.

 

Thanks. I'll try 1 layer first once I get all that 'tack off. They're noticeably heavier with the amount I put on.

 

How easy is it to hear the difference with the mods? Since it doesnt show in measurements...