[kalbee]

Thanks BMF!

Looks like that dip at ~700Hz is still the main difference? Awfully similar otherwise!
Maybe the diaphragms are the same but the magnets are not.

 

[wdahm519]

Wow that's a steep 700Hz dip.

 

[Nevod]

Grand Thanks, BMF!
700 Hz still makes me suspicious, something's not right here..
The magnets look the same from outside, the magnet bars may be different, but the weitght is the same, so I doubt that. They may have saved on someting else, like gasket between baffle and driver. 
Going just from how it looks.. T50s are the most damped, having felt, they have the least dip here. T20s (minimum damping) have largest dip. T50s without felt (minimum damping) have dip approaching that of the T20s. T50s without felt but with baffle sealed (mid-damped) have the dip inbetween stock T50 and fully undamped T50..
 
Arr, suspicions, suspicions. Have to check that region on my T20s.

 

[ambchang]

Going through the Denon D2K Markl mods thread (http://www.head-fi.org/t/299627/how-to-build-one-of-the-worlds-finest-dynamic-headphones-markl-denon-ah-d5000-mods), he recommended using
Polyester Fiberfill instead of cotton due to the better acoustic capabilities.  Wondering if anybody has tried that.
 
I am thinking of getting a bag and try it for myself.
 
Also, seems like the principles of modding the D2K and the T50-RPs are very similar (damping, stuffing earpads), just wondering why the manufacturers are not doing so themselves.

 

[satwilson]

Quote:

 

I actually had some real reservations about the NFB-12.  I really wanted it to sound good, and first impressions were nice, but I have developed a major concern around the bass.  At lower frequencies, on my unit the harmonic distortion, especially third order, is quite audible on tones on my unit.  It's at a level I have never heard from a piece of commercial gear before...  The mids are nice, and the high end, and there is power to spare, but the more I listen, the more that HD in the lower requesters bothers me.  
 
My DACPort sounds materially better, and the iBasso D12, while lacking the prodigious power of the NFB12, still provides a very nice and articulate listening experience with ample power, and it's portable to boot, so after you build an O2, you could use it for travel, office, etc, so the money isn't wasted.  I would really consider a DACPort or a D12.  The D12 is a bit more then at the NFB12 and the DACPort is 2x the cost so YMMV...
 

I was just wondering if you had any thoughts regarding the HD you hear in the bass. Which model NFB12 do you have? Is this present with just the T50s, or other phones also? Coming from the DAC, AMP, combo? I do not have the experience with other units you have, nor the critical ears to discern said HD. Just wondering if it is the amp, maybe changing to an O2 will give me even better sound for my T50s.

 

[kalbee]

Going through the Denon D2K Markl mods thread (http://www.head-fi.org/t/299627/how-to-build-one-of-the-worlds-finest-dynamic-headphones-markl-denon-ah-d5000-mods), he recommended using

Polyester Fiberfill instead of cotton due to the better acoustic capabilities.  Wondering if anybody has tried that.


 


I am thinking of getting a bag and try it for myself.


 


Also, seems like the principles of modding the D2K and the T50-RPs are very similar (damping, stuffing earpads), just wondering why the manufacturers are not doing so themselves.

 
 


You mean to say the principle of modding closed headphones are the same! Cause they just are, unless there is a bad fault that first needs to get out of way. :b

Yes, Fiberfill has been used by some members. I think the limiting factor with not using that is just due to availability on hand. Cotton is more common as household product so...
In fact I have no idea where Fiberfill is sold. Never tried searching thought, if that explains anything @.@ maybe soon, if I intend to keep my cups stuffed.

 

[TierAngst]

Fiberfill isn't hard to come by, any craft section should have it. Is there a specific brand and grade of fiberfill that works best though?

 

[rhythmdevils]

If it's easy to source, then try some and let us know! 

 

[kalbee]

Hm... interesting I'll take a look sometime soon! Oddly enough I love the big arts and craft store we have around here (called Omer Deserres) but I can't find most of the stuff you guys mention here! such as felt and etc. I guess it's probably because its more of a (fine) arts store but yeah... Will find a day to go to a fabric store instead. Thanks
 
Right, meanwhile I went to the dollarshop to hunt for possible materials to use... and then I found a sheet of miniature artificial grass... wonder if anyone had experience with anything as spikey as that

I'm gonna have a go instead with some double sided tape plunged into shredded paper... That should be quite some random diffusion. ...I'm expecting some nasty results.
 
*EDIT* ehh this very old tape can't even stick paper shreds. that was a stupid idea lol

 

[bluemonkeyflyer]

Grand Thanks, BMF!
700 Hz still makes me suspicious, something's not right here..
The magnets look the same from outside, the magnet bars may be different, but the weitght is the same, so I doubt that. They may have saved on someting else, like gasket between baffle and driver. 
Going just from how it looks.. T50s are the most damped, having felt, they have the least dip here. T20s (minimum damping) have largest dip. T50s without felt (minimum damping) have dip approaching that of the T20s. T50s without felt but with baffle sealed (mid-damped) have the dip inbetween stock T50 and fully undamped T50..
 
Arr, suspicions, suspicions. Have to check that region on my T20s.

The T20RP white driver dampener looks different compared to the paper on the T50RP. It appears more dense and of a different composition. It does not look as porous as the T50RP paper.

The cup vents are covered with a single layer of very porous mesh instead of felt.

There is no plate covering the central screw compartment.

The driver appears to be the same as the T50RP. It has a single baffle port like the T50RP.

Mods that work for me on the T50RP do not work on the T20RP. This one will require a different approach.

 

[wdahm519]

Quote:

Grand Thanks, BMF!
700 Hz still makes me suspicious, something's not right here..
The magnets look the same from outside, the magnet bars may be different, but the weitght is the same, so I doubt that. They may have saved on someting else, like gasket between baffle and driver. 
Going just from how it looks.. T50s are the most damped, having felt, they have the least dip here. T20s (minimum damping) have largest dip. T50s without felt (minimum damping) have dip approaching that of the T20s. T50s without felt but with baffle sealed (mid-damped) have the dip inbetween stock T50 and fully undamped T50..
 
Arr, suspicions, suspicions. Have to check that region on my T20s.

Depending on where you are relative to the natural frequency of the system, adding damping can actually raise the amplitude of vibrations.  This occurs when the induced frequency divided by the natural frequency of the system is greater than the square root of 2 in the case of base excitation, which is how I would model it.
 
To back up my claim, you can see here:
 

 

 

[RexAeterna]

Fiberfill isn't hard to come by, any craft section should have it. Is there a specific brand and grade of fiberfill that works best though?

pillows,stuffed animals,ect. has fiberfill inside. can get just about anywhere that sells furniture or art supplies. it's used all the time for speaker boxes. it's great for slowing down reflections by making the driver believe it's in a bigger enclosure. i think i mentioned it about over 50 times as of now. i am not sure,but, anways...yea,fiberfill is easy to come by. much better material is fiberglass. can use fiberglass for complete absorption. great for completely absorbing and completely eliminating frequency resonance down to the deepest sub-bass.

 

[TierAngst]

Is there fiberglass dedicated to sound or is it something like a small bit of blown in insulation that you'd have to find?

 

[RexAeterna]

Is there fiberglass dedicated to sound or is it something like a small bit of blown in insulation that you'd have to find?

i don't understand very well. are you asking if there a specific type of fiberglass for sound only? if i'm getting that,then no. owens rigid fiberglass can be bought locally at home dept or other home improvement stores. fiberglass is very cheap. it's used also for speaker boxes and room acoustics. people use fiberglass all the time to make acoustic panels and so forth for their rooms or for studios. if your afraid to touch fiberglass or some type of phobia there is always rockwool/mineral wool. same benefits as fiberglass but cost a bit more though. you can buy them in small bats/bags for couple bucks. i would just get the fiberglass though...well...cause it's pink and you know, pink is pretty nice color.

 

[crisnee]

I have some extra Dynamat, I was going to mod a second pair of T50rp's but my getting them fell through (It was really weird. SonicFiber said they shipped them, they even sent a UPS tracking #, but whenever I checked the # it said the item was ready to ship and that's all. Eventually I got in touch with SonicFiber and they said they'd check into it. Eventually they said UPS lost the HPs. Somehow I don't believe them, it seems bogus. But they did refund my money so... .) So if anyone needs a small quantity, I'll sell it in 9x12" pieces for what it cost me, something like $8.00 plus whatever shipping would be. PM me, if you want some. I have about 4 pieces, I think.
 
-Chris