DIY talk

No, it does not. Point source means the area emmitting energy has small diameter compared to wavelength - at least in physics.
In acoustics it is no secret to any seasoned hobbyist the rule of thumb is half wavelength.
Widebander for speakers does not fulfill that criteria, in general. Headphones are tricky, the cup is close boundary.

We have alternative physics for headphones?

You tell that loud enough and someone will rise up and shout "challenge accepted".
I'd be willing to try a 70 + mm dynamic driver mated to 20..30 mm tweeter inside a headphone.
Xo set to 200 Hz or lower.
Makes plenty sense to me.

 

Yes but headphones are a different animal. #1, if you were to go with the above, you would need a pinpoint transducer - there's no such thing. #2, even if you did have a pinpoint transducer, shooting the highs directly into your ear hole would not be realistic. In real life we don't experience sounds that way. High frequency information (as all other information) hits the entirety of the ear and the brain makes sense of it all. If you want real-sounding you need to mimic real world. Point source is relative to ear and head, not the ear canal.

Wideband speakers are apples to oranges in relation to headphone drivers. They need to be big to displace an entire room's worth of air to produce low frequencies. And because they're big, they're not well suited to high frequencies. A headphone driver (as I mentioned before) needs to displace a relatively tiny volume of air (the space between the driver and the ear) to reproduce low frequencies.

That's a different discussion that has nothing to do with the idea of point source. It's a discussion about room treatment (to an extreme degree compared to a listening room).

No. But we do have a different environment.

Sure. There are IEMs with 95 drivers, headphones with multiple drivers, and even a planar with quasi-multiple drivers (the inner and outer traces of Meze Empy and Elite). But none of those scenarios stand out as clear giants among the rest.

And since this all started with discussion of high frequency reproduction, it's generally accepted that electrostat cans have the best highs. Yet they are a single driver that doesn't fit the small diameter/wavelength ratio.

But, with everything being a trade-off, the ultimate question is: is the optimum solution a single driver with the various compromises that it entails or multiple drivers with all the tradeoffs that that entails.

I would venture a guess: if multiple drivers was the better solution, most headphones would have multiple drivers. The people engineering these things are not all idiots.

 

Wait, are they actually up to 95 now? I think I've seen 20+, but not much more than that.

 

I have no idea. I made up that number to highlight the absurdity.

 

I know you've heard Voxativs. But you need to hear the treble from my OBs
(Then again I know my electronics wouldn't satisfy you)

I don't think anyone expects Accuton BD or BlieSMa T34B/D levels of treble finesse from a widebander, though. But in my experience I still think phase shifts and driver location is audible and generally not my type of compromise compared to the best widebanders. (Well, I'm talking about 2 ways, since bass needs surface area)
But who knows... Maybe I'll change my mind when I hear your speakers at High End in a week.

Btw: the 4" AL honeycomb sandwich widebander has as much energy at 20kHz off-axis as the 25mm SB tweeter has. So beaming can be a non-issue.


A competent 2 way headphone hasn't been done yet. Maybe it can be done, but I remain skeptical.

 

Exactly - they have visoon to how low r&d costs yield producable (profitable) products that consumer finds appealing. Every pioneer has been deemed crazy, idiot or veird by contemporaries. I hope to see some crazy hp engineers.
Multiway headphone wouldn't even be that innovative. For car analogy it would be Tesla or Nissan Leaf - finally making 100 y o tech usable.

There I recognize two variables. One is xo-s in speakers are rarely matured fully.
The other is there is an xo in the first place. All components modify sound - this is the only argument in favour of widebander I like.

For hp use the driver spacing issue might be a thing - but then it might not. A big planar or other driver is smearing the timing and phase response anyways. Difference from speaker is also angular distribution. There is something like 30 deg angle distribution from driver to ear hole.

 

Plenty of $3K to $6K headphones that are priced that way simply because they can and have nothing to do with R&D costs. And plenty of consumers buying them.

In Hi Fi there's often no correlation between R&D and manufacturing and the price of a product. Quite the opposite. Use a 60 year old design, put some fancy wording in the brochure, price it astronomically to create exclusivity and watch it fly out the door.

Sorry but R&D costs are not the reason for the general lack of multi driver headphones.

 

I mean you can have a two way with no electrical crossover on the widebander, hint hint ;P