[musicfan145]

For those like me who are too sloppy to be able to use paper templates to cut a soft material to a precise shape and size, I have created a couple of 3D printable templates that should help in cutting the soft parts needed for this project. 
 
First is a template for cutting a gasket to seal between the cup and baffle plate:
 

 
 
Next is a template for cutting the felt/foam damping material on the ear-side of the baffle plate:
 

 
 
These are STL files, so just print them as you do the cups and baffles (any material or resolution is fine), then clean up the edges with some sandpaper. This will give you a 2mm thick stiff template that can be held on top of the soft material to guide your knife or marker more precisely than paper.
 
NOTE: These shapes represent the maximum amount of material you would want to include, so keep that in mind as you cut. If you use the template to mark lines on your material before cutting, don't cut on the line; you will need to cut inside the line on the outside edges and outside the line on the inside edges. 

 

[antdroid]

Just finshed my first test set with the stock Open Alphas. I used the cheapest 3D Printing possible just to try it out. It cost me about $9 to get the whole set. 
 

 

 

Open Alpha next to my other modded T50RP Mk3

 

[Wuthoqquan]

To make matters worse, once I started taping over vent holes to tune the bass, I found the upper mids and highs to still be lacking compared to what I experienced with the modded MK3. (In the modded MK3, I actually had to tame the highs with 2 layers of toilet paper.)

This is exactly what I'm also missing in my Alpha! As already pointed out in a previous post, I'm perfectly happy with the body, layering and overall definition of the bass (two vent holes closed) but I would have hoped for a better definition and extension in the upper mids and highs, similarly to your findings! I understand you are using the Alpha Pads, so you might still be able to catch up on the higher frequencies by switching to different pads. In my case, the Brainwavz HM5 are my current pads of choice... so I'm not sure what kind of fine tuning is still available to me in terms of pads.

Additionally, after quite some more hours of 'critical' listening, I'd say that I can also perceive a very tiny level of resonance, especially when listening to more 'congested' and 'faster' music. This is something that may suggest the that the cups and baffles (driver side) be lined up also with Dynamat (in addition to the acoustic foam).

I'd like to get more feedback specifically on this last point. ABS and plastic in general are notoriously materials that can be prone to vibrations/resonances. I'm probably really nitpicking here, but I still believe that with some kind of music there are indeed slight hints of resonances.

Also, someone gave my son one of those "Boogie Board" drawing tablets, and it came in a sleeve made of stiff felt about 3mm thick. I don't think he'll miss the sleeve if I cut it up and make damping material out of it. 

 

[PeterJensen]

I'd like to get more feedback specifically on this last point. ABS and plastic in general are notoriously materials that can be prone to vibrations/resonances. I'm probably really nitpicking here, but I still believe that with some kind of music there are indeed slight hints of resonances.
 

 
I haven't heard the same problem in mine, but I probably also haven't put in the same amount of critical listening. My cups are PLA and baffle were printet on an SLA printer with a UV curing material that is quiet tough.
 
However, I also thought about doing the same as it gave good results on the regular mods, but I am afraid of loosing too much cup volume if I line cups and baffle with dynamat. If anyone actually does it at some point, then I would like to hear about the differences experienced...

 

[PeterJensen]

  For those like me who are too sloppy to be able to use paper templates to cut a soft material to a precise shape and size, I have created a couple of 3D printable templates that should help in cutting the soft parts needed for this project. 

 
I thought of doing the same but never got around to do it. Thank you for your contributions with reinforced cups and these new STL´s, I am sure your good work will be appreciated by many builders in future builds, myself included

 (and thanks for praising my cups although I guess I just got lucky with the material...)
 
Your build looks great btw, I really like the coherent look of the entire headphone and the matte finish....

 

[PeterJensen]

  Just finshed my first test set with the stock Open Alphas. I used the cheapest 3D Printing possible just to try it out. It cost me about $9 to get the whole set. 

 
Looks good. Are those the Hi-Rose connectors? Looks like some alternative solution to me?
 
Seems like you have stock pads on the Alpha and HM5 on the MK3 Mod? Did you have a chance to compare the two builds using the same pads? Would be interesting to hear about the differences.

 

[rendyG]

Just finshed my first test set with the stock Open Alphas. I used the cheapest 3D Printing possible just to try it out. It cost me about $9 to get the whole set. 









Open Alpha next to my other modded T50RP Mk3

I would also love to hear a comparison between modded mk3 and alphas (you could also share how is your mk3 modded). Cheers!

 

[Wuthoqquan]

I would also love to hear a comparison between modded mk3 and alphas (you could also share how is your mk3 modded). Cheers!

 
I'm also casting my vote for a comparison between the Open Alpha and the modded MK3, possibly using the same pads.
 
Thanks!

 

[antdroid]

I would also love to hear a comparison between modded mk3 and alphas (you could also share how is your mk3 modded). Cheers!

I will have to do that in a few days. Turns out, my gloss coat wasnt fully cured and i have embedded finger prints in it while tightening some screws. I have it taken apart and started to resand the surface down for repainting this weekend.

On both mods, i use a craft molding foam called Floam to cover the back of the cup. I used a thin layer of black felt over it on the alphas, but not on the stock cups. I also currently have shure 840 pads on the alphas and brainwavz sheepskin leather pads on t50rp mk3s.

Initially without any mods on the alphas, it was near impossible to drive. After adding the floam and felt, it started to sound clearer and added depth. Ill have to follow up when i have a working set again next week.

 

[Wuthoqquan]

However, I also thought about doing the same as it gave good results on the regular mods, but I am afraid of loosing too much cup volume if I line cups and baffle with dynamat. If anyone actually does it at some point, then I would like to hear about the differences experienced...

I would only line the baffle (internal side) with Dynamat, all around the driver, since that should be the area which is more exposed to vibrations. Being the Dynamat less than 2mm thick, the loss of cup volume would be negligible if the cups are left unchanged and lined with paxmate only.

I shall also try to do some tube rolling on the amp (Alo Continental V5) I'm using with the Open Alpha and see how that will Impact on the frequency response. There are many variables in the equation indeed...

 

[CoffeeCutie]

 
Heh.  Halfway there...

 

[Eudis]

For those interested.


Here's the difference between both drivers.




The biggest sonic difference, imo, between the two is mk2 has less 2kHz-9kHz compared to the mk3. Both retain their spike. Mk3 is bassier due to the open porting at the top.

 

[nereus]

Has anyone reused the stock cable with the hirose jacks? 

 

[audiolibrarian]

  Has anyone reused the stock cable with the hirose jacks? 

 
When you say stock cable are you referring to the the cables inside the cups that connected the pcb or are you referring to the actual 3.5mm cable? I don't see an issue with using the original, but I'm new to this myself.

 

[nereus]

The stock 1/4 to 1/8 cable, just want a reconfirmation on what colours the left and right channel is if I wire it up.