Venturing into T50RP MK3 mods.

Discussion in 'Modifications and Tweaks' started by MF_Kitten, May 18, 2016.

  1. MF_Kitten

    MF_Kitten Banned per own request

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    I decided to pop open my MK3's today and mess with the guts to see what happens.

    So far I have:
    -covered the driver with two layers of cotton bandage material (non-woven sheet). Good idea, as it brought the treble spikes way down into humane territory.

    -covered 4 vent holes around the driver side of the baffle, leaving the other 4 open. Probably a good idea, assuming these do indeed vent bass away from the driver, lowering the bass entirely.

    -tried dynamat over the cup vents. Bad idea, removed too much bass. Removed dynamat, which tore off the original tape material that covered the vents. Bad idea. Luckily I had automotive felt tape handy, and replaced it with that. Good idea.
    -Covered two of four vents with dynamat over this felt tape. Bad idea, since the felt tape is already less air permeable than the original paper/cloth tape. Removed dynamat, which didn't affect the felt tape, but did bring the bass back!

    -stuffed the cups with about 1,5 or 2 grams of medical cotton that I fluffed a bit first. I have no idea if this did anything worthwhile yet.

    Does anyone have specific ideas for mod procedures that they would like to share? I'd love to know some of the secret sauce! I'm considering blocking off ALL the vents on the baffle, and maybe blocking the vents on the cups a little to compensate. I want less of a peak at 100Hz and more sub bass, while hopefully keeping the overall bass quantity. The treble just needs to be lowered, which I accomplished pretty well so far. If I can lower the treble and increase the bass, while making the peaks wider and lower in general, I'll have succeeded. Has anyone gotten there successfully?
     
  2. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    1. You'll have to find the right amount of port sealing in the cups (back of the enclosure) based on your tastes.

    2. Consider UltraTouch denim insulation for internal damping. Just cut out a square and stick it in the cups. Note: Very dusty, and since I believe the Mk3 has an open spot on the back of the driver, you might want to find a similar paper material to cover that opening. I used a very fine mesh on mine (dust filter for computer fan).

    3. Seal up the front of the baffle, at least mostly. Do this to tastes, but I preferred all the way.

    4. Play around with various front damping materials, around and/or in front of the driver. I think I used a mixture of creatology adhesive foam and bath mat (thicker than drawer liner). Foam around the driver can work too. I think I used a bit of foam with a hole cut in the middle in front of the driver.

    5. Try different pads. Making sure you don't have air leaking out from the side of the driver and under the pads is very important. If the Mk3 has the pad mounting plastic thingy right around the driver, I would use a circular strip of some sort of non-permeable material to prevent anything going under the thingy.

    Just some thoughts based on my experience with the TH500RP, and some of those designs transferred to the Mk3.
     
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  3. MF_Kitten

    MF_Kitten Banned per own request

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    The MK3 has foam around the driver already actually, which the baffle ports vent "into". I'm keeping it there just for the sake of dampening any high end reflections off of the plastic surface around the driver. The foam is taller than the driver too, and you can use the foam to hold any driver dampening in place by cutting it to the right size and just stuffing it in there over the driver. It'll be held in by friction against the driver.

    In the Head-Fi incremental mods thread, sealing baffle vents increases sub-bass extension in measurements, and stuffing cotton into the cups boosts that sub bass. My next move, I think, will be to seal all the baffle vents with felt tape instead of half of them with dynamat. Two layers of felt tape should be basically airtight.

    I might cut the cotton bandage material to squares and only stuff it into the foam cutout over the driver rather than covering the whole underside of the foam as it's doing now.

    Medical cotton bandage materials are perfect for headphones btw. They are air permeable, because they need to "breathe".

    I haven't yet used dynamat on the back of the baffle around the driver. Might try that out.
     
  4. spoony

    spoony Spooky

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    Dynamat would indeed be most effective providing mass to the baffle. Besides sealing the baffle ports and tuning the cup vents to reduce boominess, you can try applying further dampening to the driver directly in a controlled fashion in the form of permeable materials of varying thicknesses, this will reduce bass bloat and bring up the 2-6 KHz area which is slightly recessed in the mk3 revisions.
     
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  5. MF_Kitten

    MF_Kitten Banned per own request

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    I don't mind the recessed 2-3Khz range actually, as I prefer that softness in the lower treble. It also works well with the downward slope I want to work towards.

    I want a lot of bass. I just don't want it all in one place. I've made an EQ setting that makes it pretty much perfect. If I can approximate that setting with physical changes, I'd be super happy.

    Any ideas in terms of raising the high end from above 10Khz? I want less treble in the spiky range, but adding more presence/air above it would be great.
     
  6. MF_Kitten

    MF_Kitten Banned per own request

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    Update! I did some messing around with the baffle ports. If you completely cover the driver-side vents with duct tape (I mean, it's THE right thing for the job, isn't it?!) you do get more deep bass. However, do NOT cover the rear ports on the baffle. Those act more like ports than the baffle vents.

    The way it works is that the channel you slip the ear pad lip into is also where the rear ports vent. So if you cover either the channel or the rear baffle ports (the two patches of black paper), you lose bass.

    I replaced the vent tape with automotive felt tape (which breathes well, as it turns out), covered the drivers with three layers of cotton-ish stuff I have available, and then a thick layer of felt. This worked well with the high end! I'd still love to replace the cotton with thick dense felt, so I can attenuate a larger range of highs instead of getting most of the "air" and leaving the lower treble less attenuated. Something that can attenuate down to 2khz or more would be perfect.

    The cotton in the cups turned out to be interesting stuff. I realized that the best way to use it in these is to use a nice thick square piece, cut out a square where the cup vents are, so they aren't covered, and then put the baffle back on. This gives you a lot of the benefits that the cotton provides in the cup, but without restricting airflow through the vents. So you get bass extension without getting less bass!

    Here's the current readout for my modded cans:
    https://www.dropbox.com/s/zp2sv6t115dhhqc/modded.jpg?dl=0

    edit: Blue is stock with Hybrid pads. I lined them up at the lower treble peak, since that's where you sense most of the loudness. So this graph is more representative of what it SOUNDS like.
     
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  7. JK47

    JK47 The Beer Houdini

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  8. spoony

    spoony Spooky

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    It looks you went a bit overboard with the filters; the air is mostly gone. I'd try more earpads first to see if the treble peak gets better so you only have to apply a little TP, many felts kill the air.
     
  9. MF_Kitten

    MF_Kitten Banned per own request

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    I'm revisiting it once I have better materials. I can't get the air back without also letting the lower treble jump way back up.
     
  10. spoony

    spoony Spooky

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    I've had better luck with velour earpads in the treble department.
     
  11. MF_Kitten

    MF_Kitten Banned per own request

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    I had that thought too actually. Then I tried going back to HM5 Hybrid pads, but those were awful without extra dampening of the highs. Angled pleather pads bring up bass, but more mid-bass than anything else.

    The problem is that simply adding more and more dampening will eventually leave too much mids.
     
  12. spoony

    spoony Spooky

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    Pads first, then stuff the cups with whatever, lightly if possible.
     
  13. MF_Kitten

    MF_Kitten Banned per own request

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    I'm back to hybrid pads now, as they guve the best immediate results. I want to double check what the sound is like with pleathers with closed vents, but I think this is it for now.

    Has anyone had alright results with treble reflectors? I want more 10k, but not more 3-4k...

    My current setup is a thin layer of dense cotton on the back of the cups just to dampen reflections, open vents that I cut out holes for in the cotton so it remains open, 4 layers of TP in front of the drivers, held in place by a thick piece of pretty stiff felt. Baffle vents sealed with duct tape.

    It sounds very close to good. Not perfect, but very close! I need to lower treble and mid bass still. Which is surprisingly hard to isolate.
     
  14. spoony

    spoony Spooky

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    You can reduce cup venting to flatten the bass, try blocking 3/4 'slits' to see how you like it. More 10 KHz?, take out some of that TP, 'treble reflectors' don't boost the 3-6 KHz range, I wouldn't know if they even make a difference. The perfect pad in my opinion would have a pleather outer rim to help bass extension and velour inner rim to absorb some of the treble, who's up to the task?
     
  15. MF_Kitten

    MF_Kitten Banned per own request

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    That's almost literally what the HM5 hybrid pads are.

    The problem with removing TP and felt is that while it brings up 10khz, it also brings back OW MY EARS 3-5KHZ RANGE. I want to try and dampen all the high end as one, and then use a treble reflector to only reflect back the highest frequencies, in an attempt to bring tat back up. That way I can balance the treble to my taste.
     
  16. spoony

    spoony Spooky

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    My ears and measurements of the stock pair acknowledge a dip between 2-6 KHz, if you are not dampening the driver further I see no reason why it should be raised, try removing some cotton perhaps? In general, toilet paper / felt filtering range do not reach that low, 6 KHz bottom.
     
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  17. Armaegis

    Armaegis Friend

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    Treble reflectors never sound right to me. Yeah the objective measurements might be flatter, but there's a paper-iness to the sound that never works out.
     
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  18. Rex Aeterna

    Rex Aeterna Friend

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    the fostex driver naturally starts to roll off around 10khz. it is perfectly normal and sounds fine. it provides enough air response. all i did with my fostex t50rp's was rip felt pads off, stuffed some fiberglass in the cups, added some shure 840 pads and threw in some akg 240 foam disc pads in the shure pads and put cotton balls to fluff the pads out better....bass response with headphones are all bout ear coupling pressure from what i notice. the shure 840 pads provided more coupling compared to my akg 240 earpads providing better air pressure delivery and less air leakage. the 240 pads give like a akg type of brightness unless the 240 foam discs were used and it gave less bass within from low-bass to mid-bass...

    i never used anything other than traditional dampening materials before. dynamat is tar that is messy and the silver layer over it is more of reflector than anything since it is not transparent. the tar it uses helps stop any form of mechanical back waves from the driver energy, but does not actually absorb the energy, which in result in less/no modulation between enclosure and back driver... year tar is porous and can be very good absorber but, if exposed and that can be messy. dynamat is not exposed tar. it's good for stopping mechanical vibrations. that's why tar is used in car automotive undercoating sprays to quiet the vehicle down from engine/suspension vibrations and of course from subwoofer vibrations if have a subwoofer(s).....
     
    Last edited: May 26, 2016
  19. MF_Kitten

    MF_Kitten Banned per own request

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    Yeah, dynamat is only really good for holding things still.
     
  20. MF_Kitten

    MF_Kitten Banned per own request

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    I've been modding a very odd and special set of headphones lately, and I think the stuff I'm learning could be of use to any Tx0RP modders. On the back of the driver, you can add "filtered" reflectors. By that, I mean an absorber and a reflector layered together.

    The idea is that sound comes out from the back of the driver, goes through an absorber, and what's left is reflected, passes through the absorber again, and goes back into the driver to reinforce the sound.

    By adding micropore tape (surgical tape) to the two outer rows (treating the square grid on the back of the driver as a set of 3x3 rows), you get more sub bass. And some more treble. By then adding thick strips of felt and micropore on top of those again, or maybe even TP and then mocropore, you're getting more dampening, but you're also reflecting those frequencies back, and reinforcing them in the driver. So while that tape by itself reflects highs and sub bass, the absorbent material between it and the driver eats the high end before it's reflected back to the driver!

    This approach worked pretty damn well, so I'm working on different absorbers and reflectors to channel the most intense sub bass I can without adding any high end bloat :)

    Edit: holy DAMN this approach works well!!! I might actually make an even more extreme version of this...

    Basically, looking at the driver as a 3x3 grid, I put one strip of surgical tape over the white driver paper (MK2 driver, so omit these if you have a mk3 I think) on the two outer rows (not the one with the hole in the paper for youmk3 owners). Then I put thick stiff felt strips over these, same width, and then two more layers of surgical tape over the felt. Make sure that middle row is completely uncovered!

    Then here's the thing that put it over the edge for me... DUCT TAPE OVER THE FELT STRIPS AFTER THE SURGICAL TAPE!

    Yes, seriously!
    What this does is focus all the sub bass. It's like the sub lows want to escape, and you have to keep them in there, but only after making sure the treable is eaten up first. Very interesting!
     
    Last edited: May 30, 2016

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