[catom]

So I had an itch for some new cans and during a lengthy research process I realized Focal uses drivers with a rubber surround. More like normal loudspeakers for bookshelf speakers for instance. Curious. Maybe even daft for such a small space close to your ears?

Anyway, I didn't get Focal. I went with a used pair of Audioquest NightOwls. Maybe I'll get Focal in the future, but whatever, the point is as it turns out the NightHawk and NightOwls also use rubber surround with their drivers. I didn't realize this at first, but later read about it. Interesting.

How many other headphones do this?? I started googling but of course the results are about "surround sound" Ugh. Ok. But I did manage to find a pair of gaming headphones that used drivers with rubber surround too. So is there something to this? Is it just an obscure trend that doesn't necessarily result in any kind of real benefit? Difference, sure, but what's the point I wonder?

So I dig deeper and saw a company going on about LSR (liquid silicon rubber) surround drivers. I start Googling "LSR" now and I turn up more results, this time for more in-ear type earphones. They aren't necessarily expensive either.

Ok, so it's not any fancy moon technology. It's just different. Make senese... But is there a list of headphones that use this technique? What kind of difference does it make?

I'm curious, for science of course. Or is it all marketing and no science?

 

[Dogmatrix]

Generally a thin flexible surround allows more of the driver to present a linear piston type movement
With a conventional one piece plastic driver quite a large proportion is taken up between the fixed baffle and the moving coil
Only the area within the diameter of the coil presents a linear piston type movement the rest is increasingly restricted toward the fixed baffle

 

[LenAlex]

LIST: I believe the two current options are:
(a) Focal headphones (several)
(b) iBasso SR1 & SR2
(c) Audioquest (several)

so it seems you already know about 2 out of 3.

 

[bigshot]

I don't know about headphones, but rubber surrounds isn't all that great on speakers, except perhaps for sub woofers where a lot of excursion is necessary. Foam surrounds tend to rot prematurely and can be sloppy. The best woofers I have are 15 inch JBLs with cloth surrounds.

 

[71 dB]

I don't know about headphones, but rubber surrounds isn't all that great on speakers, except perhaps for sub woofers where a lot of excursion is necessary. Foam surrounds tend to rot prematurely and can be sloppy. The best woofers I have are 15 inch JBLs with cloth surrounds.

Indeed foam has the problem of rotting prematurely, but why do you say cloth is better than rubber?

 

[bigshot]

Cloth lasts a vey long time and it can handle loud volumes better. The JBLs with cloth surrounds are the speaker used in many vintage Bass guitar stage equipment.

 

[bfreedma]

Indeed foam has the problem of rotting prematurely, but why do you say cloth is better than rubber?

Cloth isn’t better than rubber. There are advantages and drawbacks to both.

People trying to make blanket statements about one material being better than another material usually don’t understand the materials science involved and may be trying to justify purchases.

The “best“ material is dependent on the use case and environmental factors.

 

[bigshot]

Cloth lasts longer and is better at higher volumes. It’s better for larger speakers.

 

[Dogmatrix]

As I read the question I think it is more concerned with potential advantage vs marketing of a roll surround design vs a mono type construction

 

[The Jester]

As with speakers, depends on the intended design,
With speakers in a sealed box there’s less cone excursion than in a vented enclosure which can affect the choice of surround material, maybe it’s similar with headphone drivers ?
Would need a more detailed study to see if there’s any correlation between closed vs open back headphones and the driver/ surround design ?

 

[Davesrose]

Cloth lasts longer and is better at higher volumes. It’s better for larger speakers.

Except, as you said earlier: subwoofers with high excursion. For my home theater setup, I did design a 12" subwoofer with high excursion driver that (as most subwoofer drivers) have rubber surround. I do agree that cloth is better than foam for typical loudspeakers (and I've "refoamed" vintage speakers with cloth surrounds). One thing I have found out about shoes: there are different types of rubber: and some can degrade fairly quickly depending on their type and moisture in environment. I would think the same about speaker surrounds: hopefully they are a rubber that's more resilient.

 

[bigshot]

Yeah absolutely. My sub is 12 inches and has foam surrounds, and my mains have 15 inch woofers with cloth. The sub is about seven years old and might last another ten years if I'm lucky. But the cloth surround woofers are almost 50 years old and still going strong!

 

[71 dB]

With speakers in a sealed box there’s less cone excursion than in a vented enclosure

This is frequency-dependent. At the lowest frequencies (clearly below the tuning frequence) the cone excursion of a vented speaker is bigger, but at the tuning frequence the cone excursion in a vented enclosure is smaller, because the resonance causes opposite pressure on to the driver. If you have a vented speaker tuned say at 50 Hz and you make it a sealed box by clogging the reflex port you will experience incresed harmonic distortion around 50 Hz, but reduced harmonic distortion at frequencies well below 50 Hz.

The lowest frequencies are the achilles heel of vented speakers, but this can be dealt with using TransFlex enclosure (mixture of reflex and transmission line enclosures). At the lowest frequencies this kind of speaker behaves more like a sealed box and at the tuning frequency more like a vented box minimising the cone excusion at all frequencies. For example Finnish Chorus Compact 662 and 682 speakers use TransFlex enclosures. My father has the 662 model and the way this small bookshelf speaker handles bass like a much bigger sealed box speaker would is impressive.

Transflex enclosure​

 

[AT Khan]

So I had an itch for some new cans and during a lengthy research process I realized Focal uses drivers with a rubber surround. More like normal loudspeakers for bookshelf speakers for instance. Curious. Maybe even daft for such a small space close to your ears?

Anyway, I didn't get Focal. I went with a used pair of Audioquest NightOwls. Maybe I'll get Focal in the future, but whatever, the point is as it turns out the NightHawk and NightOwls also use rubber surround with their drivers. I didn't realize this at first, but later read about it. Interesting.

How many other headphones do this?? I started googling but of course the results are about "surround sound" Ugh. Ok. But I did manage to find a pair of gaming headphones that used drivers with rubber surround too. So is there something to this? Is it just an obscure trend that doesn't necessarily result in any kind of real benefit? Difference, sure, but what's the point I wonder?

So I dig deeper and saw a company going on about LSR (liquid silicon rubber) surround drivers. I start Googling "LSR" now and I turn up more results, this time for more in-ear type earphones. They aren't necessarily expensive either.

Ok, so it's not any fancy moon technology. It's just different. Make senese... But is there a list of headphones that use this technique? What kind of difference does it make?

I'm curious, for science of course. Or is it all marketing and no science?

Am I too late to the party?

Anyhow, I'll just add some of my own thoughts here, if it makes any sense.

So yes I clearly have a deep fascination with headphones drivers that have a discrete kind of surround being used on the drivers.
Most headphone drivers manufacturers don't do that - but then things pop up, like of course, Audioquest headphone drivers, most of the Denon/Fostex/Foster headphones lineups, even some older JVC (the old cult classics Japan Victor Corporation line), the godlike Sony MDR-R10, probably based off similar driver tech. You see, most of these have that silicone/free-edge surround that they use. That's why I love my EMU Teaks.

Then we have the Focals - the lots of them, with their rubber surrounds. Why I love my Elex.

ZMF too...

Now here's a rare player (rare for those who may not know): Apple. Apple Earpods, at least the original ones, down to even the Airpods gen 1 (not sure of later variants), also have silicon surrounds, and most interesting, paper/composite cones like Fosters (before you go on the hate here, the OG earpods are my favorite in-ears far as sound is concerned. I think for $10, they nail it!):

Now I'm not certain why, maybe it's in my head, but I feel that decoupling the cone from the baffle like that, using surrounds, on headphone drivers, may help with a more linear and a more quicker movement. Most folks here will agree that for dynamic drivers, the kind of dynamics and quick, fast sound the Focals and the Denons/Fosters offer is quite the feat. These dynamics are almost as fast as your average planar magnetic drivers.

Now I have no data or statistics and really nothing more than a hunch to come up with this kind of a theory, but say if the whole cone or diaphragm is a uniform material with not a lot of design offsets (going to exclude at least the HD800 line here, where they have a different and uniquely design dia altogether), the cone may not move as linearly as it's glued to the edges. At those points, the cone movement will be minimal, while in the middle, the cone would move the maximum. Theoretically, the cone is being bent here, and with higher extrusions, it will become more and more non-linear.

I guess this is where the surrounds step in. Of course, one point would be that the circular wavy pattern on the cone should act as that flexible element to let the excursion take place more accurately and linearly, but it's still the same material throughout. At least the cone isn't being 'tied down' at the edges. Most of the time, I've felt the effect most noticeable in the lows, much more profoundly that the mids and the highs.

I've definitely experienced better and quicker dynamics in all these drivers with 'surrounds'. Material here doesn't matter as much, as long as it's more flexible than the diaphragm, as in these examples.

There are meh examples out there too - headphones that didn't really impress the crowd. Now this may suggest that these headphones were simply tuned bad, or that maybe this diaphragm theory is plain bull crap.

Examples: Vokyl Erupt, BLON BL 30; drivers:

Again - all this could be BS - or it may actually have some logic.

 

[bigshot]

Lows are considerably less directional than miss or highs. I think your surround perception has more to do with your state of mind than the construction of the headphones.