Sennheiser HD650 Love (Appreciation Thread)

Stock or modded HD650?

 

Stock for now. Got Dyanamat coming my way.

 

I'm finding it pretty hard to cut an accurate circle on the Sennheiser foam inserts, they always stretch a bit when putting the pads on exposing the mesh below. Blade doesn't go through the foam properly and needs like 5 passes to go through (could just be a shitty x-acto knife)

 

I think if we follow the steps mentioned (mark with a permanent marker or something similar) the coin size hole while the pad is on the headphone then it should be easier to not mess up

 

Or you guys could get a little smart and compress the foam a bit and cut a smaller hole..

 

Don't do the foam mods if the Jotunheim will be your main amp, especially if you are listening to Metal music..

 

I'm happy to do just the Dynamat and call it a day.

 

Good idea. I'm also happy with just the Dynamat mod.

I'm using my pair of Grado 225e when I'm not satisfied with the SQ of the 650s.

 

Not interested in removing the foam discs?

 

Same experience here. I was using a new X-ACTO blade. I think this is just way the foam does. (I could not think of a way around it, anyway.)

I removed the ear pad from the headphone, shown a flashlight through the back, placed a US dime where I wanted it and used a Sharpie to trace the dime.

I got the cut line for the hole just where I wanted it, but I still ran into the situation that @nehcrow described.

 

That sounds like a happy person, right there, wonderful.

I'm still having a lot of "oh shiiiiit" moments with mine, where it surprises me on favourite tracks that I haven't heard in a while, it's really rewarding. I won't pretend that I don't still fancy HD800s for times when I want a giant image, and I do flirt with Playnarz in a filthy way, but damn if the 650/Jot combo isn't a rewarding and listenable one.

That said, may well still try the Damplifier mod on a spare pair..

 

For those having trouble cutting a hole in the front foam accurately, here is what I did.

• shine a flashlight through the driver and mark the center of the foam with a marker
• take the pad/foam off, center your desired coin on the foam, and make an outline of the perimeter
• cut out the hole using some nose hair trimming scissors like this (the short blade length helps prevent you from cutting too much)
  
• start by folding the foam at the center and making a small cut, then gradually work outwards in a spiral until you get to the inside edge of the line you marked using the coin

My foam doesn't seem to stretch too much after re-installation, so the hole size is pretty much the same as when taken out of the cups. I think I used a New Taiwan $5 coin (just slightly larger than a US nickel), as I was afraid of going too bright. For me, this size hole brings out a bit more clarity in the highs without making them too bright, though I do get a bit more sibilance than before.

 

A few suggestions you can play with that I found help with this. First I moved the damplifier pro back 1/4" away from the diaphragm hole in back...actually about 3/16". This helped a bit. Next I put a layer of Merrino wool felt around the outside frame of the baffle on the backside. 1/8" thick approximately.

This made an even more noticeable improvement.

Next I put same felt on top of damplifier pro on the back of magnet structure tacking it down with the sticky butyl rubber from another piece. I also shaped everything to overlap the entire structure so my damplifier was relatively continuous. This I did by simply plucking off bits of the butyl rubber and applying them to shape it. Then I tried 1/8" by 1/4" strips of foam around the inside edge of the grille itself. the 1/4" facing up and down and the 1/8" applied to the edge of the grille itself.

This was less noticeable but uniformly smoothed the sound.

All of these mods improved detail and resolution and improved staging and focus. All added up they made a considerable improvement in the sound. This is all done with soft open cell foam. Filter foam works or you can try the foam by mail store on line. Have to check the link again. Don't remember off the top of my head.

I also used the same type of foam and made a filter for the back hole about half the thickness of the original back plug and simply tucked it in place against the magnet back using the felt on the magnet back to hold it in place. Could tack it down but it holds pretty much on its own.

I ultimately found that open back sounded the smoothest to me, meaning I removed the grille. From this I determined the grille itself created a bit of these colorations and a bit of midbass pluminess that somewhat bothered me. My solution was to create my own grilles!










You will notice I initially sealed all 4 paper ports. This is something Hands mentioned and suggested! Which has the most snap and best transient response but was a bit too much in midbass. So I settled on two ports which you can see here!

In the end I also slightly changed the grilles. I cut them from a flat office file grating rather than a pencil can
grating as these ones are. There is a slight distortion of the holes based on flattening the curvature of the can. They will actually stay in place on there own, but I tacked them down with Dynamat Extreme. Had plenty of that,
only a sample of Damplifier Pro. You can shape them by pushing them into the back of the 650 grilles...Slowly
and you have to adjust the bend as you go so as not to crimp the edges and tear them. You will get some dents
and inconsistents but just smooth them to a uniform shape after pushing them in and then readust to the grilles
as necessary.

You can get these cheap at a dollar store or Walmart. I also painted them metallic blue with nail polish. Don't have picture yet!

Will also be redoing a set of new inside foam filter to get an exact nickel sized hole rather than one that is a bit
futzed from a quarter size. I believe the nickel size sounds smoother and more refined!

Happy Listening

 

What a commitment to perfecting the sound. Those should be called Franken-650s!

 

Totally forgot about this! This is the AKG Foam and Coin mod. I also did the dynamat mod which you can find a couple hundred pages back.

 

My 650 just arrived in the mail! Completely stock and out of the Ember (low output Z, high gain, 6dj8) it sounds very nice: some instrument details seem a bit "hazier" and the soundstage definitely feels smaller than HD800, but it's a very pleasant sound signature overall. Not what I would call all that dark, really.
Female vocals are just perfect. Male vocals sound a touch nasal/tinny.
Why didn't I just buy this all those years ago and saved myself all the trouble of going through mid-fi (and even hifi) purgatory?

 

Good question

I don't know any headphones which do female focals better than HD6X0, maybe there are a few which a equally good but I can't think of any that are better.

BTW - I did the coin mod and I think I messed up. Made the hole too big and it got a little bit too siblant. I ordered 4 more foam pads and I'll give it another go. They were cheap.

 

Hands suggested glueing rug liner with paper glue stick. I did! tacked it down once to remove excess glue then down to front baffle. Also nickel coin mod and using nickel cut out to cover back hole. Significant improvement across the board
Try it! You will not be disappoonted.

Happy Listening!


.

 

Dynamat applied, as per @AustinValentine's post. I think the bass is snappier now, which also makes it feel more prominent than vocals.
I may have to do the rear foam mod to bring the vocals back up.

Edit: Oh and big thank you to @Gaspasser for sending me the Dynamat! You're a champ.

 

Sennheiser foam pads work nicely for a rear plug after you cut the coin size hole out of them. I like that a bit better than completely open! Consider if you pulling the foam out of the back and remove the foam assy on the back! The amount of paper paste/ glue stick you use on the back of the toolbox or rug liner makes a difference if you decide to tack it down to the front baffle. I did two application on the flat side of the rug liner than lightly tacked it to a piece of wood to even it out and remove excess glue, then lightly set on some scrap cloth tacking it again. Still plenty to hold down to baffle and it sounded a bit more evenly balanced then applying straight to baffle without the removal process. Tried it both ways! New front pad holes are just slightly smaller than a nickel and definetly sound the
best. Will next try the old foam pads as a more even thickness grille edge diffraction damper.

Happy Listening