|
Post by miiksu on Dec 13, 2018 17:21:39 GMT
Thank you Frans. I think they measure bretty well. I can still do some adjustment later on. Interesting measurements. My mod and thick velour pads. So smooth upper frequencies. Maybe I need to do something to my sheep skin pads... Also I'm now tempted to do some listening tests too. The bass has deeper dip 150-200 Hz.
And EQ with velours. I got it bretty smooth easily. +2, -9. Some dips occured after EQ. I can do it even better. Need more fine tuning.
Edit. HD681 is typo I mean HD688.
|
|
|
Post by miiksu on Dec 13, 2018 11:31:03 GMT
I just received the HD 688 that solderdude recommened. I have to say I am a bit disappointed. Headband is pressing too hard, I have to find a way to losen it. But most importantly audio is unprecise. I am not an audiophile and I notice it. Listening to Ice Cube Check yo self and I am noticing this. I wonder how much better it will get with modding. Have yet to try the Velours Pads. The stock ones are even worse than the Presonus HD7 from what I remember. In every aspect. I liked the HD7 more. The only upside to this one is that I dont get headaches after a couple of highs. edit: Same with Set Fire to the Rain. Man I am listening with my Sennheise HD 212 Pro. They are so good. I should appreciate them more. And I think I prefer it over Over-Ear. They fit perfectly the thick pads from eBay are super comfy. I can measure them when I got home.
|
|
|
Post by miiksu on Dec 9, 2018 18:20:25 GMT
|
|
|
Post by miiksu on Dec 9, 2018 13:54:22 GMT
Press on your skin around your ears and you'll notice the soft part is very thin. I figured I'd mimic something close to it. The materials used should 'feel' about the same. Made the device the same width and height as my own head so clamping force would be the same as the real thing. Maybe I will rebuild mine a bit more contoured to headshape one day. Some headphones with big pads don't seal well on a flat plate and need some help. Feels quite same... Slightly harder than my own skin. Maybe that will do for now Yeah clamping force is dificult atm I need do some better station for it. Mic is ECM 888 B from Superlux and t.bone micplug usb. I use battery not phantom power. My DAC is XiangSheng DAC-01A and I use dual to mono LME49990MA OPamp. This it looks now: Some "Eh" mesuerements. HD581 proto (again) HD688. Green is my mod and white is my mod + EQ. It have slightly too much upper frequencier otherwise it's quite flat. No sibilance or muddy bass. I think could do better job with inside of the cups. Need bass more down.
|
|
|
Post by miiksu on Dec 9, 2018 10:55:53 GMT
I use a thick piece wood (to mimic bone/skull a bit) and a thin layer of closed rubber cell-foam. This creates a good seal. To mimic poor seal I stick readingglasses or a small plug between the pad and rig to see its effects. This way perfect seal and lesser seal can be seen. Thank you. For the great tip. I got now more bass. One side note the upper frequencies are not anymore that much elevated with that HD581 prototype. I had quite much elevated bass with HD688. I think it's more closer what u really hear, except human perceive differency that actual measuring. I try to do proper measurements soon. Is a piece hard wood, a dense foam, a silicone/rubber good combo?
|
|
|
Post by miiksu on Dec 8, 2018 19:21:50 GMT
vs Below 500Hz there are quite some differences. May be some leakage ? Maybe open foam rubber is used ? Above 500Hz there are similarities though the peaks at 8Kz and 13kHz differ in amplitude. At least it will show changes made during modifications. First I was using opean foam. Then duck tape with foam. Now foam with ducktape and covered with microfiber cloth. The cloth is glued to the base. I'm getting there slowly. HD681 prototype
|
|
|
Post by miiksu on Dec 8, 2018 13:44:38 GMT
I made some fix to my measurements. Less bleeding. Still can't ably excact same measurements you had. HD581 proto - left channel HD688 - left channel
|
|
|
Post by miiksu on Dec 8, 2018 11:58:53 GMT
Can you measure a 'well documented' headphone with your rig ? Why I did not do that on first place... Seems my bass is quite a lot off from ur measurements. I give u some measurements today. But I still like the HD688 sound even it can have more bass than I measured on first place.
|
|
|
Post by miiksu on Dec 7, 2018 15:42:58 GMT
My latest measurements. I'm getting there slowly. I have not much listened with headphones lately, more like loudspeakers. But now I had some time I played again with EQ. I need to get that tiny spiky around 4kHz down a bit. Otherwise I'm quite happy with these. Bass is nice punchy just there and it goes deep enough, maybe it could be slightly more prominent.
|
|
|
Post by miiksu on Sept 24, 2018 5:30:45 GMT
You can try a cotton pad. Good compromise was for the HD687 is one cotton pad and no original foam pad. Two cotton pads was more flat up to 10kHz, after that upper frequencies had lowered quite much. I have not tested the HD688 with cotton pads. The cotton was over everything ? Right now i'm like this: headaudio.weebly.com/clanky/modifikujeme-akg-k712-pro with two felt disk donut cutted (the hole is like 50 € cents more or less), leaving the voice coil free, and fixed with some tape at the edges of the baffle. The result is interesting, just maybe not the best for the bass, but easy to do. Now they are way less edgy. I used oval shaped cotton pads and I positiond them, did not cover two or three holes, the opposite of the open hole. Can't say how it works with HD688.
|
|
|
Post by miiksu on Aug 14, 2018 17:15:09 GMT
Hi again. Recently i have try to find another kind of solution for improving them a bit, using those deep pads, 2 pieces of toilet paper's ply over the holes ( 1 screwed a bit the imaging, imho ), following the advices of Solderdude on the cups ( foam cutted, adding felt, hole's modification on the driver ). I was using them with 1 ply of paper over the entire driver and the foam disk of the HD681EVO, but i wasn't that convinced by the results, at least with those pads, that are very comfortable anyway. So i have take away the paper and the disk and cut a disk of the same measure, but of synthetic felt, around 1.5mm of thickness, when measured with my caliper. I feel them more smooth now, but strangely also more airy. Isn't that strange ? Dunno, is like i feel that the felt address better some peaks and resonances than what was doing the combo paper/foam disk, at least with those leatherette's pads with their fixed internal foam. Take that with a grain of salt, but i think it was worth it overall. They still need some EQ around 3k, obviously. You can try a cotton pad. Good compromise was for the HD687 is one cotton pad and no original foam pad. Two cotton pads was more flat up to 10kHz, after that upper frequencies had lowered quite much. I have not tested the HD688 with cotton pads.
|
|
|
Post by miiksu on Jul 18, 2018 18:58:57 GMT
Treble was too high for my first measurement. Not sure what caused this. I try later on with original pads. My mic is ECM888B. I made better mod for the HD687. Now they really sound good. Placed cotton pad (oval) the front side and leaved two closed holes not covered (need to be exactly on right spot). Also removed original foam sheet. Not anymore that unusual high treble. It may be my bad measurements. For my ears sweep tone is also smooth. No drops. I need to get that treble still down. Too much for my ears. Now it's 'only' +6dB. Edit. Two oval cotton pad on the front and foam pad removed. Yay! Let's rock baby. Leveled the sound more. I think this is the best I can do at the moment. Slightly elevated mid bass and treble. I tried many combinations of TP, foam pads, microfiber and active carbon fiber. You only need oval shaped cotton pads and these ear pads: www.ebay.com/itm/For-AKG-K240-S-K241-K242-K270-K-Series-Headphones-Ear-Pads-Seals-Velour-thicker/122893437911?hash=item1c9d050bd7:g:Ji4AAOSwg8taTEcr Edit2. I made 3 dB lined zone. With two cotton pads it's more balanced sounding. Even on the first look one cotton pad may look better. The first picture's quality is bad. Sorry about that.
|
|
|
Post by miiksu on Jul 17, 2018 12:41:11 GMT
I got the HD687. For my quick impressions they sound OK. Deep bass slacking and slightly too much highs. Not as good as HD688 but not bad. I finally got my measurement microphone. Not sure is it positioned right but here is my first measurements. It have Frans TP mod and my thick hybrid pads from ebay. Probably need more TP. Left channel only
|
|
|
Post by miiksu on Jul 10, 2018 5:47:04 GMT
You can try active carbon filter sheets. air passes easily and not overly dampen higher frequencies. One problem on those is u need alot more than TP and it will get thick. But I think that passive is way to go From your experience how much is "thick?" 2-3 mm ply. I used 1mm x 3 plys on different headphones. Need thick pads also.
|
|
|
Post by miiksu on Jul 9, 2018 9:05:43 GMT
You can try active carbon filter sheets. air passes easily and not overly dampen higher frequencies. One problem on those is u need alot more than TP and it will get thick. But I think that passive is way to go
|
|