Discussion in 'Headphone Measurements' started by purr1n, Sep 27, 2015.
Needs more pilcrow.
Can someone provide a link for Jupiter audio research ? I'd like to bookmark it for later use !
He doesn't have a link as of yet. There is an unofficial loaner going on (here & at head-fi) or he's ext1 on head fi
( https://www.head-fi.org/members/ext1.460358/ )
I finally went through the trouble of modding my 6xx (KISS mod but rear foam removed, love me that midbass bump). It's been awhile since I heard the JAR mod, but I feel like I did a decent job of replicating the benefits I noticed in the JAR mod, but with a slightly more relaxed presentation (since I kept the front foam stock, not sure if I want to coin mod) and more presence in the midbass. Even though @Hands measured an increase in the midbass for the JAR mod, I really didn't find it as noticeable as I do in my DIY mod (probably because there was so much treble to counterbalance it or the JAR mod runs its dampening closer to the rear vent).
I hope that the KISS mod instructions could be updated to have a note about the spacing of the magnet dampening strips and how crucial their spacing to each other as well as to the vent affects midbass response as well as channel balance; I definitely winged it at first and one driver's strips were mm closer together than the other and it noticeably affected the channel balance in the midbass.
Purchased HD650 from @EagleWings. Sounds different to me. I've owned the original (circa 2003) HD650 and the update. Kept the update as a reference, though I've never been able to figure out the serial number. It is taped up on the outside of the box (seems to be 317529xxxx). And neither my eyes nor my iPhone can seem to focus on the number inside the cup:
Here's the thing. I tried to also take pictures of the just-purchased HD650:
I could change the camera angle, but there's no serial on either cup. Serial is only on the box (346680xxxx). Versus all my other HD650, it's bright!
I've heard this pair back to back against my then stock 6xx and @EagleWings and I both noticed the same thing. Not sure how or why they would change it versus the 6xx; my only thought was that it wasn't broken in long enough and the pads are much newer which also affects the sound.
Frankenheiser lives! It is back with more mpingo then before . While I'm waiting for an upgrade to my Mad Scientist Carbon Fiber Auteur cables...decided to juice up Frankie's one more time. You know that means there must be another improvement somewhere. Sure enuff! Mpingo ebony puck madness. Looks kind a like a drone...lol! Yup even bigger improvement hanging them off the bottom. Yeah it's kind of tribal! Etc. But oh my. Increased detail more ambiance and harmonic and tonal gradations are more pronounced. Speaking of voices...they are more intelligible. Just plain more alive and involving! Dynamics small and Large also a bit better!
Even Happier Listening!
Revamped the upper ones location and mounting. More improvement!
I'm about 93% sure that says: 3175 292219
EDIT: After rotating and sharpening a bit with an image editor I got the code to scan with my phone. It confirms 3175292219.
Is that a very normal looking fabric or paper around the driver instead of the usual silvery threads? Or is that just something about the camera angle or lighting? It seems to me if they've really changed that it would definitely have a pretty significant impact on the sound... I have no clue what the silvery stuff is, but I would assume they did a lot of research to come up with it versus a plain ordinary tissue type material.
Maybe it's just the lighting, but somehow I'd swear the plastic seems cheaper too (it seems cut better, but it looks softer and less dense.) Does it affect the bass?
Bass is similar, though I'm not particular about bass. I don't listen to a lot of music with hard-hitting bass. So as long as it doesn't "rumble", distort, or bloat too terribly badly, I'm not going to notice. Did not hear a bass difference. I will take a closer look at the material.
Silver material did look significantly different to my eyes. Does it age?
I could be completely wrong about the plastic even. It just seems that way from the picture. But that could be the lighting. It may be they're still using the exact same plastic really. Unless you want to cut each fairly deeply to see if it really is softer or not it's hard to say how to really tell other than a general feel that I don't even know how to explain. It would affect sound and perhaps more than just the bass, but the bass would be the most notable (much more distortion on a less dense plastic I imagine.)
If it does it doesn't age like that. Unless it's the camera it's even making it look like the alignment of the material is different (it seems to vary by section there as if the material was applied separately to each section instead of being one contiguous material glued down.) It really looks to me like that's a very normal paper or cloth compared to whatever Sennheiser has been using (something nylon based? I have no clue...) Probably weaker and softer (careful not to poke holes in it,) but, more importantly, this might be the key reason it seems brighter.
The silver thing is actually nylon mesh. I took apart a spare headphone to figure it out with chemical reactants and precision scale. The old black one was denser nylon, denser weave, thus more attenuation.
I was figuring out the mod HD650K in "advanced materials" version. It seems the Dynamat/Creatology composite padding is too strong in high frequencies. Turns out Comply Foam is about perfect on the magnet, but then low frequency damping is lessened which is audible. On the other hand, outer plastics are perfectly fine with denser thicker PU semi-open cell foam. (Different, stiffer than creatology)
So, I went for a rich dumb solution, bought some (Pro-Ject Audio Systems Damp It) phono/speaker foot spacers and attached them with thin creatology-like foam on the plastic post-spider sides. 5-6 mm thick. Takes one of these feet cut into quarters to do it, very tough material to cut, recommending a serrated knife or a saw.
(I think, it's sorbothane as seller said or similar TPU, rated and measured by me as 20-500 Hz high damping. It behaves kinda like my sorbothane sample but somewhat less viscuous?)
What this mod did is... moved soundstage forward, very slightly narrowed it (due to reduced openness of the cup). And *vastly* improved bass handling. I didn't quite expect it to be this effective.
The sound is supremely clean and immediate now.
The hemi-rings also ensure the magnet can never fall off by sheer compression working as a kind of spider. (Original one is removed as per KISS) I suspect it also dampens any residual low freq vibration in the mesh, mass loads the magnet and acts as a mild HF reflector without introducing resonances.
Here's a result pic. Removing the grille is mildly hazardous as it can cause the heavy hemi-rings to detach and they have to be pushed back in onto the adhesive foam.
And here's the eq correction. Note: 7.3k cut is related to my crossfeed and is an average of interference artifact. Ignore that if not using my crossfeed.
EDIT: Also added crossfeed settings.
Can't see the picture, but you described something very close to my setup, I'm using these with double sided tape, they fit perfectly.
How can I use your crossfeed?
And yes, the google images don't work (no access)
Sure, you can find the crossfeed attached... somewhere... on the forums here. It got a minor update but I haven't rebuilt it for Windows just yet. Soon though. The previous version is sonically equivalent but has fewer controls.
Album with description:
Here are the direct image links if you don't like imgur album:
And the dropbox link to crossfeed: https://www.dropbox.com/s/wsqlb9rkixpmzdy/adv_xfeed_v3.zip?dl=0
After almost 3 years, I finally replaced my pads. I'd swapped with some new ones when trying out my friend's HD58X, which convinced me to order some. The change over the years was so gradual that I hadn't noticed the increased mid-bass hump and congestion in the mids (due to bass bleed?). The new pads reduced and tightened up the mid-bass, give a perceived improvement in bass extension, and the mids sound more open and clear.
I ordered them from Amazon for $50, but a few days later when searching for HD239 pads for a friend I came across these at Audio Sanctuary in the UK that are about $15 less and with cheaper int'l shipping. I added a spare headband and front foam to my friend's order and they arrived before mine from Amazon.
Perhaps someone wants to update the Compendium.
Ahh damn, cheaper than thomann as well, it seems... Thanks for the tip!
Off topic a bit but if you found any 239 pads that are decent please PM me. My 238 pads are shot to shit, and I'm dissatisfied with the chi-fi replacement pads I bought
@Jinxy245, as I said, Audio Sanctuary. Their search function sucks but if you use Google within site or even site:uk for hd238/9 pads you'll find it.
You guys are probably sick of HD650M pics, but I don't have much else to contribute right now. First, huge shoutout to all the experimenters trying to improve the sound through modification and sharing that with everyone else. Big thanks to zonto for posting his HD650 mod reference.
I started with a used HD650 with just a few dozen hours (previous owner apparently didn't like the sound). I love my AKG K7xx and when I first got the HD650s in, I didn't like the sound either. I read that it could take anywhere from 200-1000 hours to burn in, or it's all imagination, but it didn't hurt to try. I let it play for about 200 hours and subjectively think the sound has improved. If that worked, let's ratchet it up to 11!
I approached modding the HD650 a little differently than what I've seen. First, I didn't use a coin for the coin mod. I measured the circumference of the driver and it was something like 15mm, so I cut it exactly that by creating a negative template--the opposite of using a coin--so that I couldn't cut too much. In hindsight I would've tried 2-3mm smaller, but you be the judge:
The 3 things on the left side, from top to bottom: 1) the "coin" I cut out of the foam. 2) the double-layered foam trapped under the spider cage. 3) the extricated spider cage.
Next, I removed the spider cage, but did it differently than what I've seen. It seems 1) removing the spider cage is good, but 2) the magnet potentially falling out due to the missing spider is bad. So I opted for the best of both worlds by cutting an elevated, angled cut to retain "teeth" to hold the magnet while removing the cage. Spider teeth? See below. This seems super effective and I'm very happy with the results.
Next I opted for second skin vs Dynamat since that seemed to have more support as "the best." A 3" x 5" sample strip was more than enough, even when cutting around the logo so the color would be uniform. I still have a bunch left over.
I haven't seen anyone close off the "top" which is opposite the long strip over the lollipop. Nor have I seen the sides of the lollipop strip part get covered. With the different modifications people have done, including KISS, the center around the magnet seemed the most important, so why not enclose all of it? If there's a reason please let me know! But I opted to enclose all of it.
I started by cutting the doughnut, which I thought would be the hardest, so if I could do that right, it'd be easy sailing from there. Then I decided to do more than just a strip over the lollipop, which was harder than the doughnut. I got substantially better at cutting and am thinking about redoing the doughnut because it's so rough. Again, I measured everything with a caliper so the measurements were exact. I created templates first, traced that outline with a box cutter onto the second skin--vs hobby knife, because apparently I'm a glutton for difficulty. I recommend the hobby knife (xacto). It'll be much thinner and won't deform the metal as easily. The slightest pressure on the second skin deforms the metal, squeezes the sticky tar underneath, and make it look terrible.
My approach was slightly different here in that I went with KISS+ by going all around the magnet and skipping the left and right sides. It didn't turn out as clean as I wanted, but it'll do for now.
Most importantly, after all that, how does it sound? Well, I'm unhappy in a way because I instantly knew I liked my AKG K7xx less!
WOW!!! I feel like I now understand why so many people love the HD650. Whether the sound will open up more with burn in (or it's just in my head) I'm excited to see. Without gushing about it, since all of you will have a better articulation of sound expression than me, I'll just offer a litmus test: Would I do this mod again? YES. Without hesitation. And next time I'll make it better!
Thanks for letting me join you all.
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