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Why dynamic drivers have better bass than BA drivers? - Page 4

post #46 of 73

Plenty examples of full range single driver BAs with plenty of extension both ways in this thread. Their purpose isn't extra bass but overall res. To each his own. Use your ears and buy what meets your personal needs.

post #47 of 73
So theoretically the DBA-02 is capable of being tuned to sound like the GR07?
post #48 of 73
Quote:
Originally Posted by gnarlsagan View Post

So theoretically the DBA-02 is capable of being tuned to sound like the GR07?

 

That's a tough road if you want to try tuning it that way...  But in theory, yes, it can be (theoretically) tuned to sound like the GR07...  

post #49 of 73

I don't know. I think you may be able to find a BA to tune similar to that but I doubt that it could be a twfk or that anything would sound just like it. Even dynamics ot BAs don't sound like their brothers with similar goals. Similar, perhaps but not same.

post #50 of 73
Well since custom iems have different BA's for different frequencies I'd imagine that not all BA's are created equally when it come to bass response. The diaphram needs more room to move to create deep bass notes and small armature drivers aren't as good as larger ones in this regard. A large enough BA driver should be able to match any dynamic driver.

Also, it's a different thing entirely to say that a single armature driver produces "enough" bass. We're talking about comparing bass levels of BA and dynamics regardless of what one considers" enough" to be. If someone prefers more sub-bass than what is considered flat then that person needs either a dynamic driver or a sizable BA capable of enhanced bass output.
post #51 of 73

There's a few single BA customs but I agree about everything else. There's also multi driver dynamics. It's difficult to make anything single driver extremely linear and extended. Using mutiple units allows you the versatility to better tailor to your needs. More bass a reasonable prices is the Dynamic market but it's not like there aren't other trade offs either. It's pick your poison and there isn't a wrong answer, just a right one for you.

post #52 of 73

Some of the companies producing their own drivers have experimented with different materials.
Sony  EX1000 has a liquid crystal polymer film diaphragm.
JVC FX 700 has wooden diaphragm and brass housing with exterior wooden shells.
VSonic GR-07 - bio-cellulose technology
All are famous for their smooth mids and high quality bass.
At the moment BA donot have similar technology or material selection.

sony_ex1000_06.jpg

FX700-Structure_big.jpg

GR-07Driver.png


Edited by MuZo2 - 7/13/12 at 5:24am
post #53 of 73

The materials themselves are likely overrated as there's not much in breakup modes going on. Probably has more to do with keeping the dome portion rigid enough while getting the correct surround characteristic from the same material. I'd think building something from the correct surround material and bonding a light rigid piece to the center portion would be a good way to go. I wouldn't be surprised if this was happening in some of the promising dynamic micro drivers. Perhaps the way biocellulose is formed allows better variable thickness control to achieve some of this. Paper (wood?) has always been a great material for cones. Better than some exotics depending on the formulation though probably not the best for surrounds. I just looked at the JVC after writing that and it seems bonding a stiff diaphragm to a complaint surround is exactly what they're doing.

 

Materials relate to resonance, damping, mass and compliance. Were talking frequencies here than can't become fundamentally resonance in these enclosures length and diaphragm sizes until your up around 9k or so where acoustic filters can be used but it doesn't mean materials don't matter, they do but it may be overstated as to why. Doesn't mean they can have peaks in their designs but they're not acoustic reinforcement in nature. You'll notice that the 3 examples above will still use bass and high frequency mechanical tailoring.

 

What we're dealing with in in-ears is almost entirely pistonic pressure change in the ear and not so much resonances though some can appear in the higher registers. The material of the activation lever in a BA is made from isn't that important but it they wanted to, they could change what it was made from. In fact, it's been done in the cheaper siren types that use standard dynamic looking diaphragms. There just isn't much point.


Edited by goodvibes - 7/13/12 at 11:02am
post #54 of 73

Well, BA also have some variety, they can use different damping, e.g. ferrofluidic, standard magnetic, no damping.

There could be a variety of membranes there as well.

 

About tuning DBA-02 into GR07 - not possible. Either lowest end WBFK would distort or the highest end WBFK would lack highest end energy.

This is the base TWFK curve: http://www.knowles.com/search/prods_pdf/TWFK-30017-000.pdf

You could try to come close to RE272 though.

 

It would be easier to achieve the full bass with a dampened armature like FFH: http://www.knowles.com/search/prods_pdf/FFH-23375-I02.pdf

then layering e.g. EF with the right slow crossover: http://www.knowles.com/search/prods_pdf/EF-21942-000.pdf

This would have some really... interesting impedance curve though. (Inverse of the usual armatures, and it'd need a resistive element for the high end EF.)

 

Or perhaps skip the middleman and go for the GQ armature: http://www.knowles.com/search/prods_pdf/GQ-30783-000.pdf

Now we're talking high end. (This one is WBFK + ED in one package.)

I wonder if someone uses those already in mass production. The curve looks like it'd quite match GR07, ED has more than enough bass power.

I'd expect it to be less sibilant. It's very low impedance though, so it'll need likewise source.


Edited by AstralStorm - 7/13/12 at 5:32pm
post #55 of 73

I'm pretty much with you on that but most BA's don't have normal diaphragms as we may imagine. MAs and Sirens do but I think most BA's basically use leaf spring levers as diaphragms like this Sony cutaway.

sony-xba-section1-1.jpg

I believe the ADDIEM uses a version of the GQ with their own crossover and a vent. Unfortunately, it's not tuned anything like a GR07.frown.gif


Edited by goodvibes - 7/13/12 at 7:50pm
post #56 of 73
Here's how balanced armature works....
post #57 of 73

Right and they commonly have the rod at the end where the arrows are like the sony cutaway. The top 'diaphram' is secured at the other side so it works as a lever. I called it similar to a leaf spring becaue the armature centers itself and recovers the same way a leaf spring would though that rstitution can be either by just the armature or combines with the diapragm portion.


Edited by goodvibes - 7/14/12 at 5:58pm
post #58 of 73

Yes, of course there are differences, e.g. there are 90 degree rotated armatures like the one he's shown, ones that are on vent axis, ones that have the inside filled with ferrofluid, etc.

Also variants with the drive rod being mechanically dampened - attached to the case.

Old sample: http://www.moultonworld.pwp.blueyonder.co.uk/Lecture28_page.htm

 

Moving armature instead has a drive rod being moved directly, not via bending a drive coil.

The difference from typical dynamic is that you can use a huge magnet, as it doesn't have to move.

Old sample: http://www.moultonworld.pwp.blueyonder.co.uk/Lecture29_page.htm

 

(Really, the info is quite outdated, at least by 10 years. There have been important improvements in construction of both BA and MA.)


Edited by AstralStorm - 7/14/12 at 2:23pm
post #59 of 73

I misunderstood some of the previous post so read this one with a grain regarding my defensiveness. Some good info so no redo and I'll take my lumps but my apologies to Astral.

 

Of course those designs exist and Moving armature speakers (moving iron) appeared aound 1910 and 15 years before moving coil speakers did but we're talking about what's in an IEMs and that's a cutaway of almost every BA other than a siren type mentioned regardless of sound exit position. It's pressure change so location isn't that critical. The siren has a dynamic type diaphragm with the drive rod attached to it's center. These came out a few years back as a cost effective direct replacement for dynamic type iem construction. The rest of the motor is still the same as the botton 2/3rds of the BA diagram and already mentioned. BAs are also not 'filled' with ferrofluid. There will be a small amount held in place by magnetism between the magnets and around a portion of the armature itself.

 

Moving coils have no more restriction on magnet size than BAs since the magnets are stationary in both.

 

Moving armature is not truly a balanced armature. If you look at it, it's not really balanced. I've often pointed out that because of dynamic type suspensions, they're subject to break in like or even more than dynamics. It also means they could be tuned similarly to dynamics if so desired. Bass and all. We're all aware of them by the way. I assumed it was a siren type before ClieOS posted a dagram a couple years ago. Quite different. I use one as my primary device.bigsmile_face.gif It's also unique to only 4 products world wide.

 

Here's good diagrams from the source. http://www.yashima-elec.co.jp/e/technical_information/backnumber002.html Another cutaway of a BA and MA.  Notice that in the MA, the armature is more the (rigid) diaphragm than what is noted as the diaphragm that operates more as a damper and suspension. That suspension moves a bit with the armature so it's not an improper desription but it's other functions are probably more noteworthy here. So far, they've all also been sealed so air damping as well. The diagram you gave works as well but I don't think that the ones in IEMs have the top membrane.


Edited by goodvibes - 7/14/12 at 6:44pm
post #60 of 73
Quote:
Originally Posted by goodvibes View Post

Nothing I've written is outdated. You have this habit of over reaching in a rude manner. This time after I agree with you with a minor correction. No pleasing some people.

Uh, I was talking about the papers I've linked to being outdated. Some misunderstanding... Thanks for the nice link.

(Flooded means injected in ul amounts, as it will form the membrane on its own.)

--

About GQ: there are two models. One seems like what you'd expect from a normal armature, the other, not so much. :-)


Edited by AstralStorm - 7/14/12 at 6:40pm
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