[Philimon]

O.O
The officially deemed lost by HK post RP18 @BucketInABucket sent to me 4months ago suddenly arrived. Package does not look tampered or damaged. This RP18 is nicer condition than other. Not tested yet. Wow!

 

[Philimon]

Already modded by Aria (seller), don't know all the details. And the pads are old HFM velours. Imbalance in measurements is typical and normal... Not listened yet except to see if they work.

 

[Philimon]

Havent tried these yet. They were applied with very thin sticky tape. They have a density in the middle of previous foam pads I tried. May trim them down. Super cheap, come in a pack of 10. Might work for your YHD-30i @khbaur330162 . They may also be an upgrade for Koss Porta Pro. They look and feel like Geekria brand Grado pads but smaller. Applied one backwards to see if I like.

 

[Philimon]

Both left side measurements. One is with pads sticked on frontwards, and other is backwards. Listening to them backwards because felt slightly more comfortable compared to forwards. Will try cutting thickness in half then applying very light damping, which should make more linear etc.

RP18 arriving out of the blue was shocking and kind of miraculous because such a rare headphone. They sound good, @BucketInABucket did a nice job modding. Need to test for bass rattle. Need to open cups and check on state of mods. Need to pay Aria. TY

 

[Philimon]

The mass resonance damping stuff hasnt dried and flaked out. Going to take some time to remove though.

No buzz or rattles with test tones. Yeah!

Driver shows tiny indents and one tiny crinkle, yet bass measurements came out perfectly fine. Hmmm. The other RP18 needs more analysis. They will be going to @dBel84 . He got dibs for all his contributions and helping me with a few vintage ortho repairs (at no charge). Maybe he can determine if bass imbalance was a fluke, or if its real then maybe he can figure out whats the cause and fix.

Thank you again to @BucketInABucket for her patience, time, and understanding. In return Ive offered to give her dibs on this RP18 at major discount if I ever decide to sell.

 

[Philimon]

Moving clay away from crevices and noticed this driver’s two halves are a little loose. 2/4 screws are stripped is why. Havent opened other enclosure yet.

 

[Philimon]

Forgot to mention that dBel also received the same discount offer. @BucketInABucket definitely had the most aggravation during this deal. I hope to gift her some semi-open 3DP cups for her EMU teaks later.

Forgot to add some impressions.: Too bright up top. Sorry Aria. They are a little screechy imo. Everything else was good!

Im going to reset and do my own mods because for me that is part of the fun.

 

[Philimon]

Luckily wife had some wooden pottery tools that helped immensely. Just need to wipe off with a towel. And will probably remove cup grill duster filter as its a bit caked.

 

[Philimon]

The felt in both cups were very soft and poofy and kinda gross. I think they absorbed moisture from the clay like substance. Both driver membranes had very slight crinkles not seen in the other RP18 or T30. Both had wiring without strain reliefs so I added zip ties. Not mad @BucketInABucket at all for non-mint condition (impossible), these are antiques that could have hundreds of hours of use. Just taking notes.

 

[Philimon]

The measurements are with the same HFM velour pads. Not yet concerned about the deep bass imbalance, may be a bad seal. The Hifiman pads are just held in place with friction and pressure from clamp, not perfect. Sounds good, a little too strong up top for my tastes, but an improvement over Aria's mod imo. These will be nice with less porous pads... And new enclosure.

 

[Philimon]

Voicejoy pads cut to half width. Nice.

 

[Philimon]

Half width pads reveal too much 2-3kHz.
Adding damping to full pads is alright. Will listen for a bit before deciding which I prefer between damp and no damp.

 

[khbaur330162]

New YHD-3's showed up so I made the YHD-30i's like @Philimon. They sound good, but for some reason I thought subbass was better with his pair. Now these are just better KPH-30i's, they don't really have the amazing subbass like my YHD-550's. Honestly, I've gotten used to the recessed mids on my YHD-550's, don't even care anymore. I listened to them for almost the entire day the other day with flat EQ and they were flawless.

Still waiting for the glue to dry on YHD-30i's but they are useable right now, haha. They sound good. Interesting airiness. Not much subbass, but I recently bought a Subpac M2x and this sort of replaces the bass of your headphones, so not really even that noticeable for me right now.

I wanted to see if sealing the Grado pads on KPH-30i frame with blue tac would help bass extension.

No real appreciable change. I will be using blue tac to secure the pads in place however, I hate how they shift around. Blue tac solves this problem just be sure to apply at the edge of KPH-30i frame or just offset from driver a little so it doesn't show up around the driver through pad opening.

-edit-
With the Subpac, these just absolutely smash stock YH-1's. Everything above like 60Hz is good... No damping, just glued the drivers in place and closed everything up, ez-pz.

 

[Philimon]

Ive settled on this configuration for YHD-1. No damp extra fat bass is preferred. 2-3kHz is intrusive and needs the masking effect of the midbass bump. Its not headache inducing so its liveable, similar yo Porta Pro bass quality and quantity (from iphone). A/B comparison would be interesting. Porta Pro is great btw

edit: fixed link. Its an earlier post with measurements of full width voice joy pads with no damp.

 

[Philimon]

@khbaur330162 Let me find my YHD-30i posts to see if I shared pics of internals. The cups need sealing around side edges (not on back vents). Are you using the Geekria pads? They have a denser foam than stock Koss pads. I used no extra damping. I have my set to @E_Schaaf and he has measurements as well which were very similar to my own.