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Post by miiksu on Jan 21, 2019 14:13:12 GMT
See my posts on HD688 and HD687 threads. 110mm velour pad is better than 105mm. If its more dense its good. Some chinese sellers sell lower quality pads and bass bleed out more. Good velours does not make too big difference to some pleathers.
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Post by miiksu on Jan 13, 2019 16:32:35 GMT
solderdude Yep. The dips are not that big sometimes. The caps are not so bad always they look on the measurements. I may overreacted a little.
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Post by miiksu on Jan 13, 2019 15:49:39 GMT
New pads and new mods. I got it to approx +6 / -6 dB. I need to test more but it's quite OK atm. From 4 kHz to 10 kHz could be lower otherwise quite nice. Of course after EQ it's much more pleasant and very flat. No felt is used with this modification wink My materials; a soft clay, a toilet paper, a cotton pad, a kinesio tape, a adhesive foam sheet. Cheap materials that can be finded everywhere. No irreversible modifications.
Cumulative spectrum delays as well. Got it quite clean. The driver behaves different after EQ. 2-8 kHz cleaner but then very small delays happening 9 kHz and around 18 kHz. May me possible to remove those but not sure if it's worth the time. This does not tell the impact on sound but it has damn good bass, clean middle to upper frequencies. And my mods. I filled the cups with 50 grams of soft clay and covered the rest with cotton that is splitted to half and trimmed to size in the photo. Both sides are covered with cotton. The size is not too crucial on the back side just try to mimick best as you can. If you look more closely. Also some kinesio tape or pharmacy fabric tape to the middle. It's black on my pictures. 3mm adhesive foam ring is covering the driver outlet hole, just for the edges. It slighly helped to get better bass response. So I keeped it. The toilet paper is 3-layer with three invidual layers. Thee circles 74 mm, two of them has 30 mm holes and one has 8 mm a hole. Also a cotton pad splitted to half and the hole need to be 8 mm as well but in my picture it's something like 9-10mm. A bit of error Also 3x3mm adhesive foam to cover the grill on the front, foam wall added to make more space and kinesio tape to block the hole on the front. I bought from this seller these quality pads: www.ebay.com/itm/For-AKG-K240-S-K241-K242-K270-K-Series-Headphones-Ear-Pads-Seals-Velour-thicker/122893437911?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649I recommend these new 110mm velour pads: www.ebay.com/itm/Velour-ear-pads-seals-pillow-foam-cover-Cushion-for-headphones-Full-size-for-all/323353580025?ssPageName=STRK%3AMEBIDX%3AIT&var=512414971937&_trksid=p2057872.m2749.l2649Measures slightly better and gives more volume and impact. Also better comfort because it's bigger also.
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Post by miiksu on Jan 12, 2019 18:33:30 GMT
Interesting. Even it does have velours it does not give help with the 3.5-4 kHz dip.
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Post by miiksu on Jan 7, 2019 22:40:29 GMT
I have resorted to the Superlux foam disc instead of the eco-fi felt and use it with the cloth towards the driver. The felt disc mod is a good alternative but did not like the increase around 4kHz (even though that is small). Others may welcome a bit more clarity though. Maybe mixing with one individual toilet paper sheet? I have not tried that. It may work.
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Post by miiksu on Jan 5, 2019 19:27:00 GMT
Here is the measurements of these two. It have Frans filter mod. I think the material is cleaning cloth on the front. My mod on the Mid BT headphones. Marshall headphone is for the bassheads. Damn good step response. Everytime when is the bass time it gives u nice ear massage. Middle very good and upper frequencies good. ARTA step response. Original Mod
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Post by miiksu on Jan 5, 2019 14:02:34 GMT
Update. It's more comfy than HD581 and build quality is very good. It has similar sound wave to the HD581. But on the bass side has more solid sound. Actually bass is excelent better than HD688 after some mods. HD581 gives u more airiness to the sound. I'll today compare measurements to this 35€ headphone Bluetooth version costs only 3€ more on thomann.
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Post by miiksu on Jan 3, 2019 18:58:38 GMT
I was suprised how good they sound. Flat sound except the big dip on 8 kHz and spike around 14 kHz. I made mod to it, it tames spike of the upper frequency and make the dip raise. Solid bass, clean sounding, crisp and tonal balance is neutral. But price wise not worth it. Not very comfortable for longer periods. Its cost in my country 120-169€. My measurement Punch 3.5mm hole to the cotton pad and I used again IKEA's stopp filt. Great stuff.
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Post by miiksu on Dec 30, 2018 13:26:26 GMT
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Post by miiksu on Dec 28, 2018 17:05:04 GMT
Hmm. Look at this. They now sound good and after few click EQ's they sound excelent. No expensive sheep skin pad needed. Thick pleather pads and few easy mods. I added cotton to pack of the driver and two felts and cotton to the front. The cotton may be slight problem to correct one I take some screenshots later on of the mods. Mods and thick pleather pads. Roughly +6 / -7 And few click EQ - Left only. +3.29 / - 4.75
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Post by miiksu on Dec 16, 2018 21:37:03 GMT
Looks promissing but the scale is a bit misleading making it look really flat.. 2-3khz is -17dB opposite 300Hz. Yep. Bass is good but relaxed middle and upper frequencies. I got misleading scale sorry about that. I tried many thinks and that seemed to work best for now. Felt did not work good as cotton with these headphones. Foam, toilet paper worked best on HD688 with velours. I need to try toilet paper and cotton with HD687 with the sheep skin pads.
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Post by miiksu on Dec 16, 2018 19:15:21 GMT
Another interesting measurements. They sound now snappy on bass side, no sibilance on upper frequencies. Got bigger dip around 3 kHz and after 10 kHz. Kinda heavy sound but enjoyable. Brainwavz sheep skin xl pads and two layers of oval cotton pads.
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Post by miiksu on Dec 16, 2018 11:49:02 GMT
Pad swapping has a tendency to change one aspect positively and others negatively. The driver output of the HD688 is recessed but can be lifted a few dB with EQ without too much negative effects. Interesting. I got it now better with ur advice. It's only now +6 and -12 dB. Let see if I can make it more smoother. Upper frequencies are now almot smooth but elevated. Very easy to lower and fix. But the dip need to be lower. I love the sheep skin pads. They don't make my ears hot and better attenuation for output noise. Edit. I'm getting closer. +6, -9 dB. Used three layers of felt sheets. Thickness approx 2 mm. Cutted to 100mm circles.
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Post by miiksu on Dec 15, 2018 19:46:17 GMT
I still can't get off the annoying dips around 2650 Hz and 4500 Hz. Real leather measures nicely up to 2 kHz and after that it got that big 16 dB dip. Velours it have only 6 dB dip. That kinesio tape helped slightly on the upper frequencies and some cotton added to edges but I the dip got worse.
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Post by miiksu on Dec 13, 2018 20:39:40 GMT
I'm blowed away. They sound now super nice. I have never enjoyed this much listen to postmodern jukebox records with headphones. I usually listen retro synthpop/electronic, it will also sound now very good with those. Every detail has it's place now. Not any frequency is taking the lead. Awesome tonal balance. I need buy extra pairs of these velour pads. One for the other headphones and use. Right channel is doing better.
Edit. I got chased it down to +1.6, -5.9. That dip around 14kHz may been a user error. Some of my mods got a bit off. No point really use genuine leather because it measures worse on upper frequencies. It may be the whole pad is leather and it reflect the upper frequencies. I'm thinkin to add kinesio tape to the pad sides. It may be a stupid idea.
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