[RenZixx]

Heyo
So I've made the Alpha dogs from this guide and they're great.
I've just recently made an open-back version of them as well. Anybody who has made them their self who can tell me their experience? I'll gladly tell about mine if people would like to.
I'm new on Head-fi, so I'm sorry if this ain't the right place to post this.

Welcome to head-fi! Please do share your experience!

 

[truebuie]

Well I'll let my experince out then.

First of all. Here are the parts I've used to create them.
This is the cup design I've worked out from: https://www.thingiverse.com/thing:2335662
I'm using some refurbished T50RP mk3's from Amazon. The mk3's worked surprisngly good in the original closed-back version, hence why I'm also using them here. And well, the mk2's aren't that easy to find anymore.
I'm still using using alpha pads on them, however I've thought of putting some HM5 angled velours on if I can find them anywhere in Europe.
I'm not using MrSpeakers comfort strap, but a home-made one. There's none on the open-backs at the moment, but I have one in orange in construction at the moment. It's the same concept as the the one on my closed-backs (Look at picture)

But enough talk of what they're made of. Onto the sound.
WITHOUT any form of damping/modding/filling whatever you want to call it, these are absolutely terrible. This isn't even funny. Litteraly sounds like everything over 1Khz is just cut out. When I first tried them I just sat and laughed since I couldn't believe they were this bad. I put them down after one song and went to bed. The next day I tried some new pads and some modding of the cup. The first go with pads was without me modding the cup yet. My impression was basically that all my pads made it worse or was equal to the alpa pads, except for one pair. Some AKG K701 pads I had laying around. Just for record, I tried these pads on there:

• HM5 Velour
• HM5 Hybrid
• HM5 Pleather
• HM5 Sheepskin
• HM5 Sheepskin angled
• HM5 Pleather round
• HM5 Hybrid round
• HM5 Sheepskin round XL
• China HM5 Kashmir.
• AKG K701 pads
• Sennheiser HD600 pads

Litteraly none of those pads made it work. The AKG could work, but I would not want to ruin those pads to hopefully make this headphone semi-alright.
So I just stuck with the Alpha pads and made it "work".

After this pad rolling session I decided to play around with the cup. This is where the magic happens. This turned the open-backs into semi open-backs, however this made the sound listenable. I did the following to the cup to make the sound alright:

First of all. I covered the inside walls of the cup with some Paxmate. This have worked in my DT770's to help treble come thourgh a little easier, so I thought why not try it here. What could go wrong.

Afterwards I placed some toilet paper on the back to keep the cotton inside.

Afterwards I remembered to pull out the little foam insert behind the driver. Probably should have done this before hand, but this is when I remembered it.

Now the cup is closed and I decided to replace the foam around the driver with some more Paxmate. This helped Getting more than just the low-end getting through. And afterwards I just plopped some more toilet paper over the driver. Helped getting a litlle more treble out of them.

These mods on the cup made them listenable and actually not a terrible headphone. They're not at all open sounding, but they leak like crazy. They DO NOT sound like my closed-back alpha dogs. These are more neutral in the sense that they don't have that insane low-end the closed-backs have. They have a more toned down low-end which I do actually appreciate.
I'm not sure if I'm done trying to modify these, but for now I want to see how they really sound. Only had about 30 minutes with them so far after those mods

So time for a conclusion.
If you just plop the driver inside the open-back cup they sound hidious. Like they're so god damn terrible. If you decide to mod the cup they begin to sound alright.

I'd be glad to hear other people's experience if they've made a pair. Think I'm the first one to make it in another forum I'm a part of. Hoved-fi. Litteraly a danish rip-off of Head-fi. Don't blame us.

 

[RenZixx]

Well I'll let my experince out then.

First of all. Here are the parts I've used to create them.
This is the cup design I've worked out from: https://www.thingiverse.com/thing:2335662
I'm using some refurbished T50RP mk3's from Amazon. The mk3's worked surprisngly good in the original closed-back version, hence why I'm also using them here. And well, the mk2's aren't that easy to find anymore.
I'm still using using alpha pads on them, however I've thought of putting some HM5 angled velours on if I can find them anywhere in Europe.
I'm not using MrSpeakers comfort strap, but a home-made one. There's none on the open-backs at the moment, but I have one in orange in construction at the moment. It's the same concept as the the one on my closed-backs (Look at picture)

But enough talk of what they're made of. Onto the sound.
WITHOUT any form of damping/modding/filling whatever you want to call it, these are absolutely terrible. This isn't even funny. Litteraly sounds like everything over 1Khz is just cut out. When I first tried them I just sat and laughed since I couldn't believe they were this bad. I put them down after one song and went to bed. The next day I tried some new pads and some modding of the cup. The first go with pads was without me modding the cup yet. My impression was basically that all my pads made it worse or was equal to the alpa pads, except for one pair. Some AKG K701 pads I had laying around. Just for record, I tried these pads on there:

• HM5 Velour
• HM5 Hybrid
• HM5 Pleather
• HM5 Sheepskin
• HM5 Sheepskin angled
• HM5 Pleather round
• HM5 Hybrid round
• HM5 Sheepskin round XL
• China HM5 Kashmir.
• AKG K701 pads
• Sennheiser HD600 pads

Litteraly none of those pads made it work. The AKG could work, but I would not want to ruin those pads to hopefully make this headphone semi-alright.
So I just stuck with the Alpha pads and made it "work".

After this pad rolling session I decided to play around with the cup. This is where the magic happens. This turned the open-backs into semi open-backs, however this made the sound listenable. I did the following to the cup to make the sound alright:

First of all. I covered the inside walls of the cup with some Paxmate. This have worked in my DT770's to help treble come thourgh a little easier, so I thought why not try it here. What could go wrong.

Afterwards I placed some toilet paper on the back to keep the cotton inside.

Afterwards I remembered to pull out the little foam insert behind the driver. Probably should have done this before hand, but this is when I remembered it.

Now the cup is closed and I decided to replace the foam around the driver with some more Paxmate. This helped Getting more than just the low-end getting through. And afterwards I just plopped some more toilet paper over the driver. Helped getting a litlle more treble out of them.

These mods on the cup made them listenable and actually not a terrible headphone. They're not at all open sounding, but they leak like crazy. They DO NOT sound like my closed-back alpha dogs. These are more neutral in the sense that they don't have that insane low-end the closed-backs have. They have a more toned down low-end which I do actually appreciate.
I'm not sure if I'm done trying to modify these, but for now I want to see how they really sound. Only had about 30 minutes with them so far after those mods

So time for a conclusion.
If you just plop the driver inside the open-back cup they sound hidious. Like they're so god damn terrible. If you decide to mod the cup they begin to sound alright.

I'd be glad to hear other people's experience if they've made a pair. Think I'm the first one to make it in another forum I'm a part of. Hoved-fi. Litteraly a danish rip-off of Head-fi. Don't blame us.

That's some good work there! But I wouldn't recommend putting anything in front of the driver since that would be blocking it directly and as a result you could lose alot of detail

 

[truebuie]

Yeah, I had the thought it might do that, however it just find it giving them some more sparkle. They really needed some top-end to help balance out the signature a little more.
I'm open for ideas to make them different though.

 

[RenZixx]

Yeah, I had the thought it might do that, however it just find it giving them some more sparkle. They really needed some top-end to help balance out the signature a little more.
I'm open for ideas to make them different though.

I recommend trying wool instead of cotton, the Alpha Primes use em. Also try some dynamat as that will tighten up the sound, especially the bass but when you put dynamat, put some paxmate or sound absorber on it because dynamat is a reflective material and in turn would cause treble murder

 

[truebuie]

Thanks for the ideas. Do you have any idea where it would be smart to place the dynamat? I don't have any of it at the moment, but I might know a person who can help me out.
Think I'll go get some wool and stuff it in there and see if that's going to help.

 

[RenZixx]

Thanks for the ideas. Do you have any idea where it would be smart to place the dynamat? I don't have any of it at the moment, but I might know a person who can help me out.
Think I'll go get some wool and stuff it in there and see if that's going to help.

Place a full piece on the rear part of the baffle but make sure to make a cut out for the driver.

 

[Balazar]

Heyo
So I've made the Alpha dogs from this guide and they're great.
I've just recently made an open-back version of them as well. Anybody who has made them their self who can tell me their experience? I'll gladly tell about mine if people would like to.
I'm new on Head-fi, so I'm sorry if this ain't the right place to post this.

I would really like to hear about you open back set. Pics too! I did the alphas with Mr. Speaks pads and I like them much better than my modded mk3's but I'm still working on the tuning.

 

[OkinaDaikon]

I started down the modding rabbit whole since Friday and ended ordering a pair of the mk3.

I took some time going through this thread, but I’m still a little confused about printing with 100 micron versus 200 micron. The main concern I have been is how it would affect the screw holes for ventilation?

Thanks!

 

[musicfan145]

I've just recently made an open-back version of them as well. Anybody who has made them their self who can tell me their experience? I'll gladly tell about mine if people would like to.

I'd love to hear how the open back version turned out. Given how much small changes in the earcup venting changes the sound of the semi/closed version, I'm certainly curious how they behave in an infinite baffle.

 

[OkinaDaikon]

I was wondering if someone would be able to fill me in on how the screw hole ventilations works on the original 3D print files?

I haven't found what type of screws fit into those vents and how it affects the sound?

 

[Balazar]

The original files don't have screw hole ventilation. They just have a series of holes that can be blocked to adjust tuning. You can block them with tape. I made a set of ear cup files that are modified to use m3 set screws instead. They are "infinitely adjustable". You can find them in this thread and on thingiverse.com if you do a search.

 

[OkinaDaikon]

The original files don't have screw hole ventilation. They just have a series of holes that can be blocked to adjust tuning. You can block them with tape. I made a set of ear cup files that are modified to use m3 set screws instead. They are "infinitely adjustable". You can find them in this thread and on thingiverse.com if you do a search.

I totally saw that too! i think thats design is pretty cool, i'm just not sure how to tune properly? Like i would probably love to tune them as flat as possible before I start tweaking.

Since i'm not all the familiar, I don't know where to start.

 

[Balazar]

I totally saw that too! i think thats design is pretty cool, i'm just not sure how to tune properly? Like i would probably love to tune them as flat as possible before I start tweaking.

Since i'm not all the familiar, I don't know where to start.

Just follow the instructions as Mr. Speakers has laid out. Everything is really a personal taste thing. That is why the instructions are somewhat vague on the amount of wool and such. If you do the original cups, you just assemble them and listen to your favorite reference tracks. Block off half the holes with tape from the outside. Then listen again. Try blocking off more or less holes with tape until the bass suits your taste. The screws are basically the same thing, just with screws instead. I highly recommend using an m3 tap on the hole before putting the screw in. It's easy to strip them even in plastic because the hex key used with that set screw is so small. Also different amounts of wool with have a noticeable effect, as well as pad rolling. BlueMokeyFlyer's thread "T50RP Incremental Mods and Measurements" has a lot of really good organized info on things to try and their approximate effects. Mass loading, driver damping and such. Mr. Spearkers instructions will get you to a really nice finished product. If you feel like tuning it more after that the sky is the limit.

 

[Torac]

I finally decided to follow this guide a week or so ago, all the parts finally arrived today and I can't wait to assemble everything when I get home again.
Here are some pictures of the parts I had printed on a SLA printer:

I used facfox to get them printed, they were relatively inexpensive (£80 for everything) and included in the price they sanded painted and polished the parts.