solderdude
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Post by solderdude on Feb 11, 2018 8:24:30 GMT
It seems to be a question of sonic 'resistance' different materials and different densities may well have a different 'resistance' over the entire frequency response.
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Post by miiksu on Feb 11, 2018 16:46:00 GMT
Ah, that it seems then. Thank u again. I got inspiration somehow. I got feeling these lacked a bit of punch/speed on entire frequency range. I did go a step further modding the grill. I covered the entire driver grill with foam sticks. Better dynamics. I can now say there is layers! Easy to do but needs a hour to do and thick earpads. Fast acoustic guitars was slightly edgy and messy without that mod. Now it's clearer, less edgy and persistent. Also on bass it's easier to hear variations. Vocals quite same very lively. Edit. Hmm. I was still not happy with the bass. I added thick foam ring to the driver port in the back. It lowered rumble but upper bass is now more prominent. Faster and lower. Not sure if I keep this but I like the punch on this. I added also +3 dB low shelf filter for 25 Hz to compensate. Subbass is now more like gentle summer breeze. I used Solderdude a picture as guide
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Post by superluc on Aug 14, 2018 2:27:26 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.
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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.
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Post by superluc on Sept 22, 2018 23:42:45 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.
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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.
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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.
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solderdude
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Post by solderdude on Dec 8, 2018 7:51:57 GMT
Can you measure a 'well documented' headphone with your rig ?
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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.
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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
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solderdude
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Post by solderdude on Dec 8, 2018 18:34:41 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.
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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
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solderdude
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Post by solderdude on Dec 9, 2018 9:17:01 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.
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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?
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solderdude
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Post by solderdude on Dec 9, 2018 10:59:50 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.
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