[Kabeer]

Quote:

Originally Posted by iQEM /img/forum/go_quote.gif nice post, Kabeer... how good that Telefunk-who to your other ortho ?

Quote:

Originally Posted by DefectiveAudioComponent /img/forum/go_quote.gif What a masterpiece! How does that sound?

Glad you recognise the wonderous quality of my work!

The telefunken has nice treble, and bass extends low down, but is not BIG like the bassy Yamahas i thinkl
The stock housing is completely closed behind the driver, with just HP-3 style vents around, quite a bad design for such a large driver i think.
Despite this, with the completely worn out cotton pads it sounds quite pleasant.
I also think the crappy cable+inline volume adjuster arent helping things.
The driver is a rather nice quality one, certainly its a nice headphone, not a bad one like Wualta described, so the drivers must be rather different in sound (they are radically different in looks).

I decided i wanted to open the entire driver to the ears, and have a fully open back. Problem is i had no baffle or cups to meet that need. And unlike some of the more handy people here I could not just go to a workshop and fashion out a pair.
So I Stuck the drivers in the ID apeture of my fake Sony CD3000 earpads which held them tightly in place by pressure, and sellotaped the Telefunken frame on!
(so is the ideal ortho cup no cup at all?! theres no reflections and it allows the backwave to escape more easily than anyhting??).

The sound is quite nice, i dont feel a lack in treble, bass is again all there, but not bigg. Its a little underdamped as is. Id say its a bit more neautral open sounding Yamaha HP-1 at the moment.

I need to find a way of getting good baffle and ear seal (these pads suck at sealing).
Btw, anyone know if the very outer ring of these PMB style drivers actually make sound? Im wondering if its worth sticking to the hassle of trying to find a way to keep those holes open to the air, if they really do produce treble though, then ofc its worth opening them up.

If it doesnt make sound, I think the simplest mod would be just to drill a large hole out of the back of the stock telefunken cup?

 

[wualta]

Interesting question, KBr-- does the driver produce any sound at all right next to the clamping ring. Well, it can't move very far, obviously, but you don't need something to move far to produce treble. Try this: take a disc of some sound-blocking material slighly smaller than the size of the driver itself, face it with something absorptive like glass or rock wool, and do a total-eclipse experiment. See if you can determine what comes out around the edges of an ortho driver. Or, do it the other way: block just the outer ring of holes and see if some of the treble goes away.

I suppose to do this right we'd need a tiny mic with a rubber gasket to check frequency response in individual holes.

 

[DefectiveAudioComponent]

The PMB-80 went dead on the right side, some days ago, I thought.

It didn't cut out, instead it faded out smoothly. I just tried it on my vintage Pioneer amp that has separate volume controls for each channel (instead of a balance knob). I noticed that there was very faint sound. Then I turned it up (I am not so worried about giving the PMB drivers too much power), and suddenly it went "pop" and was back at normal volume again. What happened? Did all the electrons get congested somewhere in the driver, and suddenly they got a good push and cleared the way?

 

[JadeEast]

Quote:

Originally Posted by Kabeer /img/forum/go_quote.gif (so is the ideal ortho cup no cup at all?! theres no reflections and it allows the backwave to escape more easily than anyhting??).

I think the possible roots of that driver may lend it-self to cup less life.
I've been listening to this dampening scheme.

 

[DefectiveAudioComponent]

Quote:

Originally Posted by JadeEast /img/forum/go_quote.gif I think the possible roots of that driver may lend it-self to cup less life. I've been listening to this dampening scheme.

That's the same scheme the PMB-80 uses, including the bass-cancellation vents. Does it cancel the bass of your PMB-100?


I'm beginning to think that the XcanV3 tube amp is not the best match with my PMB cans, and maybe not with the LCD-1 either. Listening to the PMB-80 though the Pioneer gives a nice bass tilt, compared to the airy highs / upper mids tilt of the Xcan. But the Xcan gives better headstage... hmm.... why can't I just get it alll...
(or maybe it's the Arcam CD player VS the 0404 usb dac? this isn't my best a/b comparison...)

 

[JadeEast]

Bass what's that?

Drops off pretty steep @ 100HZ and at 50 there is nothing.

 

[DefectiveAudioComponent]

Quote:

Originally Posted by JadeEast /img/forum/go_quote.gif Bass what's that? Drops off pretty steep @ 100HZ and at 50 there is nothing.

I recognize that.... (that's why I sealed the cancellation vents of my PMB-80)
Do you have any enjoyable music with this compromise?

 

[JadeEast]

Surprisingly allot of music is just fine without the bass extension but most anything with synth-bass sound weak.

One interesting thing is that it's pretty easy to hear what different reflex dot positional differences are when the is nothing over the driver. The higher up the ear the reflex dot is higher the frequency that gets bounced back.

I wouldn't doubt that the perception has to do with where the reflections are bouncing of my ear as it seems I can dial it in by gently placing my finger tip on different areas. This could be one of the advantages of a larger driver, delivering sound to the whole ear including the outer ear.

I imagine everyones ear shape and size really would determine the opium placement for a reflex dot.

 

[BoilermakerFan]

Quote:

Originally Posted by DefectiveAudioComponent /img/forum/go_quote.gif I recognize that.... (that's why I sealed the cancellation vents of my PMB-80) Do you have any enjoyable music with this compromise?

Instead of sealing them, why not try tuning them with Transpore of different densities of felt? The MB Quart QP805s are a sealed cup dynamic with felt tuned ports into the ear pad and it's a brilliant design. Great bass once the crap pads were changed over to J$ leather K240s or O2 pads...

 

[iQEM]

Quote:

Originally Posted by DefectiveAudioComponent /img/forum/go_quote.gif The PMB-80 went dead on the right side, some days ago, I thought. It didn't cut out, instead it faded out smoothly. I just tried it on my vintage Pioneer amp that has separate volume controls for each channel (instead of a balance knob). I noticed that there was very faint sound. Then I turned it up (I am not so worried about giving the PMB drivers too much power), and suddenly it went "pop" and was back at normal volume again. What happened? Did all the electrons get congested somewhere in the driver, and suddenly they got a good push and cleared the way?

is it possible the magnet has loosen ? cos' if you guys remember i had sent several broken drivers (of YH100, HP50A & DR11) to Don and came back normally...but suddenly after several weeks the glue became loosen and some of em' became imbalance and the other not stable, sometimes just dead...
when i pressed the magnet it came back to life BUT fade out and then gone...so i clamp em' using 3 or 4 binder clip then re-glued all over the magnet again and leave em until the glue strong enough to hold em...
+ i give 1 small clamp from metal plate to press the magnet firmly...luckily it's normal again, without imbalance or such thing like that again...
so maybe you can give it a try, DAC...check the magnet if it being loosen up or not...

 

[Kabeer]

Quote:

Originally Posted by iQEM /img/forum/go_quote.gif is it possible the magnet has loosen ? cos' if you guys remember i had sent several broken drivers (of YH100, HP50A & DR11) to Don and came back normally...but suddenly after several weeks the glue became loosen and some of em' became imbalance and the other not stable, sometimes just dead... when i pressed the magnet it came back to life BUT fade out and then gone...so i clamp em' using 3 or 4 binder clip then re-glued all over the magnet again and leave em until the glue strong enough to hold em... + i give 1 small clamp from metal plate to press the magnet firmly...luckily it's normal again, without imbalance or such thing like that again... so maybe you can give it a try, DAC...check the magnet if it being loosen up or not...

Oooh, this might be a possibility...as the PMB is clamped. (although i do remember the clamping force was quite good, but maybe microns make a difference?

 

[dBel84]

It looks like our silent readers are paying attention...

The latest HE5 showing some anterior damping and there is a felt disc on the rear too - sounding better an all

..dB

 

[smeggy]

Nice and....Holy crap, that wood's thin! No wonder they were having cracking problems. That's a lot of nuts an bolts in there. I wonder if they're all assembled by hand.

 

[DefectiveAudioComponent]

Quote:

Originally Posted by dBel84 /img/forum/go_quote.gif It looks like our silent readers are paying attention... The latest HE5 showing some anterior damping and there is a felt disc on the rear too - sounding better an all ..dB

Is that star shape just a decoration or does it do something, you think? It appears strange to have a decoration there, since it's not supposed to be opened... (How did you open it, by the way? I thought it couldn't be opened?)

 

[smeggy]

Moar thunderpantsand stuff