Orthodynamic Roundup

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leeperry said:

humm, I'm listening to the HP-1 again....why all the fuss about the T50RP again? 

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General availability? Cost? Ease of modding? 

 

rexaeterna said:

i auditioned a slightly modded hp-1 before,while i did enjoy the sound very much and it's power handling surprised me the most without any sign of clipping, it was kinda on warm side of things but nice kind of warm sound that was very pleasant while remaining very clear. it was very enjoyable. my modded fostex t50rp are defiantly much more close to very natural sounding with high levels of clarity and low-level detail with defiantly much more top-end and bottom-end extension and more open sound. the hp-1 are awesome headphone and great introduction to vintage orthos if you can drive them well.

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Yep, I guess that's also why I hated the T20v2...these vintage orthos require killer amping and I didn't have a beefy amp at the time. I kept reading that the HP-1 was bass shy, huh? This thing has a rumbling percussive deep bass on the DP-1(its drivers are closer the ear canals than on the T50RP, so that also drastically helps). I have never heard this kind of bass slam on the T50RP.
 
But yes, the mids are "warmer" and less detailed...but it reproduces ambiences far more naturally and yes, the trebles are slightly rolled off, but I'm really stunned by the holographic sound, mids creaminess and bass slam. I'm gonna take it from there, and from what I've seen its drivers are rather easy to transplant into Beyer shells, so I can foresee good things happening for me in the future
 
And tbh, comfort has always been a major issue for me on the T50RP. I come from +15yo of cd1k/3k, their shell is like a feather on the top of your head and nothing neither puts strain on the top of your skull or your pinnas. After a few hours w/ the T50RP, it always feels like torture..this must stop.
 
Another issue for me is that the T50RP has a very low impedance, and I hardly get any headroom on the stepped volume pots of my amps...blame it on their engineers that didn't provide a gain switch, but I do appreciate the higher impedance of the HP-1.
 
I've got no plan whatsoever to get conned into the LCD-2/LCD-3 but the new HE-400 sounds very promising, I'm eager to hear honest feedback about it. Too bad its impedance is so low...who would use a full size ortho off a DAP, huh.
 

micmacmo said:

General availability? Cost? Ease of modding? 

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Point taken! But indeed, it's not because its drivers were computer engineered that they subjectively kill all previous ortho generations. Lesson learned.

Quote:

leeperry said:

humm, I'm listening to the HP-1 again....why all the fuss about the T50RP again? This thing does pretty much everything better as it would appear

 
 

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Aside from the performance/price ratio, The T50RP is more or less readily available, reliable, reasonably well built, and still in production (supporting a company like Fostex for continuing a product like this, at a price point like it is - is well worth it, imo.)
 
I love the vintage Ortho's - but they take some dedication to find, restore, and love. 

I am not looking for anything in particular. I came acress this tread while researching the HP-1. I would like to see what improvement can be made by damping. Would you recommend one or two layers of felt to start?
 
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defectiveaudiocomponent said:

What you hear is a good starting point. What would you like to improve by damping? 
(If you are not sure, then it's a good idea to try some different things for yourself to get an idea about it.)

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Some HIFIMAN HE-400 initial impressions, courtesy of warp08:
 
http://www.head-fi.org/t/586885/new-hifiman-headphone-he-400-is-out/150#post_8022230

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boiler81 said:

I am not looking for anything in particular. I came acress this tread while researching the HP-1. I would like to see what improvement can be made by damping. Would you recommend one or two layers of felt to start?

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There are different kinds of felt - some is very dense, other felt is rather transparent. So, that would depend on what felt you have. But I have not damped the HP-1 myself, so I will not give you any specific advice - others can do that. I'll give you some good directions instead:
 
This is a good place to look first: http://wiki.faust3d.com/wiki/index.php?title=Yamaha_HP-1
 
Then go here to search this thread for damping the HP-1: http://headfi.qix.it/

Since we are discussing damping schemes - This is my current favourite:
 

 
No felt on the driver. No discs, donuts, tape, or other obstacles that distort the back wave. It just goes straight out the grilles.
No reflex dot.
Blutack (white, actually, although black-tack would have looked better). To seal the baffle, and lining the inner sides of the cup, to take down some cup reflections.
Lambskin leather ear pads that seal out the back wave.
 
The result is a full-bodied sound, with clear highs, and an unusually wide and accurate headstage.
 
To introduce the different damping schemes:
Dot - increases treble by reflecting the treble back wave so that it goes out through the front.
Felt - decreases / tightens up the bass. A variant of that can also be achieved by a leaky baffle, or leaky pads.
Donut - the idea is to tighten up the bass wihout spending too much of it.
Tape - really does decrease / tighten the bass up a lot. But it tends to dry out.
 
 
 

Ouh, that HE-400 preview sounds promising..but I think I'd rather wait for the next single figure HE model, because it will have a higher impedance and prolly a flatter FR too.
 
Anyway, one interesting thing w/ the HP-1 off a good source is that one day I was told that there was no point in using anything better than NE5532 based audio gear because every piece of music had gone through hundreds of those, and that there wasn't more to dig for. The T50RP has much clearer trebles than the HP-1 but when you connect it to a very good source, you quickly reach this point of digging for "noise" and distortion...so it takes high quality masterings and SACD's to make it sound excellent. A bit like these ppl who can hear up to 40kHz, it must be a real nuisance to constantly pick up so much "noise". This said, I'm still missing the trebles clarity of the T50RP...but its holographic SS and percussive bass are highly addictive

Quote:

defectiveaudiocomponent said:

Since we are discussing damping schemes - This is my current favourite:
 
 
 
No felt on the driver. No discs, donuts, tape, or other obstacles that distort the back wave. It just goes straight out the grilles.
No reflex dot.
Blutack (white, actually, although black-tack would have looked better). To seal the baffle, and lining the inner sides of the cup, to take down some cup reflections.
Lambskin leather ear pads that seal out the back wave.
 
The result is a full-bodied sound, with clear highs, and an unusually wide and accurate headstage.
 
To introduce the different damping schemes:
Dot - increases treble by reflecting the treble back wave so that it goes out through the front.
Felt - decreases / tightens up the bass. A variant of that can also be achieved by a leaky baffle, or leaky pads.
Donut - the idea is to tighten up the bass wihout spending too much of it.
Tape - really does decrease / tighten the bass up a lot. But it tends to dry out.
 
 
 

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EXCELLENT mod summary of what the various tweaks can do. It should help out people searching, but no doubt it will get buried in the rest of this thread soon.
Do you find ANY boominess or resonance issues at all with the lack of anything on the back of the driver? Obviously those aren't SFI's in that they are PMB drivers I assume. Oh yeah I can see the size of it through the mesh. Nice and fine that mesh probably little to no reflection back. ( what did you use for mesh? )
 How are the detail levels without the damping directly on the back of the driver?
I'm toying with the idea of using an SR-80 housing with something but can't decide yet if I want to pick that up and take a gamble.
 
Must sound stunning those cans.
can you refresh my memory: what housings are those again?
 
 

Quote:

defectiveaudiocomponent said:

Since we are discussing damping schemes - This is my current favourite:

 

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Don't think you can actually call this a damping scheme.
 
That said I agree that this is the correct approach with PMB drivers.I also don't have anything on the back of driver but I have stuffed a light mesh of mineral wool to take care of internal reflections in the cup.
I also did some pad rolling yesterday, my earlier impressions were with stock(?) earpads which don't seal well.
With the O2 pads the bass quantity now clearly exceeds the HP-1 and certainly would satisfy even a basshead.I am impressed.

 
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nick n said:

EXCELLENT mod summary...

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DAC, it is a good summary but there's one important niggle, and that's the statement that implies that damping with felt, and adjusting bass level by metering in bits of backwave via leaks in baffle and/or pad, are the same. One controls a diaphragm's bass resonance (if any) and makes the bass more accurate; the other simply adjusts bass quantity without improving its quality. Not that both approaches aren't equally valid, but they're not the same. Other than that, I agree.
 

I might as well add some of my experiences to this format (along with Wualta's idea)
 
Reflex Dot - increases upper mids and treble by reflecting the treble back wave so that it goes out through the front.
Felt Disc (on back of driver)- decreases / tightens up the bass by decreasing bass resonance and improves bass quality.
       - increases upper midrange and treble
Felt Donut (on back of driver) - the idea is to tighten up the bass without reducing too much of it. 
       -Felt donut gives you more soundstage than a felt disc on the back of the driver since the middle portion of the driver is exposed. 
      -The chamber this creates behind the driver also increases bass quantity.
Tape - decrease / tighten the bass up a lot. But it tends to dry out. 
       -increases upper mids and treble similarly, but not the same as felt.  Increases driver speed similar to felt.
Porous Paper- (on back of driver) increases treble with less increase in upper mids than felt.  Increases driver speed similar to felt.
Felt (in back of cups) - decreases cup resonances, can increase bass significantly especially if it is covering vents.  Can decrease soundstage.
Foam - decreases cup resonances, decreases bass quantity and depending on foam density, can increase or decrease upper mids/treble
Leaky baffle or pads- reduces bass especially lower bass and bass punch
      -increases upper mids and treble
      -increases soundstage and air
Open back - increases soundstage, improves imaging, increases upper mids and treble.  But it depends on the driver really and enclosure and opening size/shape....
      - going from no hole in the back to small hole (bass port) increases bass significantly, and as you open the back more at some point it starts to decrease bass quantity

I have put the little guide on the Wikiphonia so that we can find it again and continue with it
http://wiki.faust3d.com/wiki/index.php?title=Isodynamic_Driver_Damping
 
 

wualta said:

DAC, it is a good summary but there's one important niggle, and that's the statement that implies that damping with felt, and adjusting bass level by metering in bits of backwave via leaks in baffle and/or pad, are the same. One controls a diaphragm's bass resonance (if any) and makes the bass more accurate; the other simply adjusts bass quantity without improving its quality. Not that both approaches aren't equally valid, but they're not the same. Other than that, I agree.
 

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True. But the felt can also distort headstage, IMHO.
 

 
Quote:

defectiveaudiocomponent said:

True. But the felt can also distort headstage, IMHO.

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If by distort you merely mean narrow, yes. 
 
Thanks for putting the guide up on Wikiphonia. It's in danger of being overrun by spammers lately.

 
Quote:

nick n said:

EXCELLENT mod summary of what the various tweaks can do. It should help out people searching, but no doubt it will get buried in the rest of this thread soon.
Do you find ANY boominess or resonance issues at all with the lack of anything on the back of the driver? Obviously those aren't SFI's in that they are PMB drivers I assume. Oh yeah I can see the size of it through the mesh. Nice and fine that mesh probably little to no reflection back. ( what did you use for mesh? )
 How are the detail levels without the damping directly on the back of the driver?
I'm toying with the idea of using an SR-80 housing with something but can't decide yet if I want to pick that up and take a gamble.
 
Must sound stunning those cans.
can you refresh my memory: what housings are those again?
 
 

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They do sound stunning  Even by todays standards. Peerless / Magnat were so close to make a timeless classic headphone. It has both highs, lows, and headstage. Very unusual.
However - I have only just finished what I wanted to do with it. Sometimes flaws become apparent only after some time. So far, all is fine though.
 
The 55mm PMB drivers are in the stock Magnat RT 10 ' High Speed Ribbon Technology' headset. It's a typical PMB headset, but slightly better designed than the other ones I have seen. The Dual DK 830 and Peerless PMB-80 use very similar headsets. I prefer the fine wire mesh back on the Magnat to the other designs. All off them are unfortunately very uncommon.