[Pianist]

I understand that one BA driver cannot cover the full audible frequency spectrum, so you need more BA drivers for that. Shouldn't 2 be enough though? Or 3 at most? Ok, maybe 4 MAX. lol But why squeeze even more drivers in there? I heard that doing so makes each driver do less work and so allows it to produce a lower distortion, clearer, more detailed and more accurate sound, but how exactly does it work? I just don't get it. Also, isn't it extremely hard to produce an IEM with so many drivers - like say 4+ - to make them work adequately in unison? I also heard that more drivers actually have the potential to sound more coherent than less drivers and that I don't understand at all. What's the deal with that?
 
I want your thoughts on this guys.
 
 
 

 

[alphaman]

"So what exactly is the point of BA IEMs with more than 2-3 drivers?"
A quick answer: marketing; selling to those with a "keeping-up-with-the-Jonses" psychopathology,  etc.
Alternative answers: In theory, specialized "spectral" drivers (e.g., LF, MF, HF), properly crossed over, and time-aligned, and "impedance-aligned", etc., might be superior to single-driver design. I think time-aligning these drivers is important -- while you may have rich, detailed sound with good timbre, you can concomittantly end up with sloppy/congested sonics (lacking: energy, speed, pace, rhythm, dynamics, attack/decay).  
Optimal sound is a complex, multi-variable formula. And engineering science is only part of that equation. E.g., a slick manuf. can "cheat" a bit: say they introduce a burn-in/break-in step to their assembly line. Then, an unsuspecting reviewer, conducting multi-unit evaluations en masse, may favor that model over others not pre-burned-in.  
I think that IEM science is still in its infancy (I own IE-8,s, SE530s and SM3s and am not really/ultimately content with any of them -- for one, they each sound so different from one another). It'll take novel, well-designed tests and lots of empirical data before the "good stuff" appears. 

 

[SolidVictory]

I think that the number of BA's in an IEM is not a strict representation of its audio quality. The crossover implementation and tuning of the drivers is much more important. Take for example the Westone 4 and EarSonics SM3. I actually preferred the EarSonics SM3 much more than I did the Westone 4, even though the Westone 4 had more BA's than the SM3. Perhaps that is strictly my signature taste, but I also felt that the SM3 was almost technically as good as the Westone 4, but fell short. And I believe it fell short technically because the Westone 4 sounded more effortless throughout the frequency range--and I give credit to the additional drivers that the Westone 4 has over the SM3 for this technical superiority.
 
I believe that by adding more BA's, you can definitely reduce distortion and create a lot of headroom for spikes in dB for live performers. This is what Jerry Harvey mentioned as a prime reason for the 8 BA's on the JH16. I also believe that accuracy can be increased with more BA's, as there is less stress on each driver to produce a certain frequency range.
 
But overall, after having heard so many dual/triple/quad driver IEMs, I can say from my observations that more drivers generally means a better sounding IEM (with exceptions). Again, the crossover implementation and tuning are crucial. Having heard the Westone 3, Westone 4, Shure SE535, EarSonics SM3, JH16, JH13, and other multi-driver IEMs, I can safely say that to my ears, more BA's offer a cleaner, more effortless sound.
 
Out of all the multi-driver IEMs I have heard, the JH16 sounded the most effortless to me, followed by the JH13 and the Westone 4. As you can see, these are correlated with higher driver counts (that of course does not mean such a law exists, it is just my observation). Also, I believe that the complexity of implementing a good crossover and a coherent sound becomes difficult with more than 3 drivers. There is a lot of phase correction to be done at that point, with so many drivers it is hard to create a single coherent sound. Additionally, from my experience instrument separation becomes discernibly better with higher driver counts.
 
Overall, I believe higher driver counts can definitely be a beneficial thing for IEMs if it is implemented with care. The best improvement I have heard with higher driver counts is a more realistic sounding, organic representation of an atmosphere (jazz club, orchestral setting, etc.). The ambiance is captured better with more BA's in my opinion (perhaps this ties into the distortion and accuracy part, less work per BA). And finally, I feel like the music sounds more effortless with more BA's, but this of course can be true with fewer drivers as well.
 
I think it isn't an exact science. A lot depends on how the drivers are implemented and how the engineer wants the IEM to sound. It is more of an art than a science (and then there are personal preferences, which change a lot of perceptions as well).

 

[alphaman]

Just wanted to remind everyone that there are multi-element dynamics, now, too ... e.g. the new JVC FXT-90:

Dunno how it sounds. There are also dual-diaphragm dynamics like Radius.
 
IAC, & as in the case with multi-driver BA's, each driver is a separate element that consumes space in a chassis that is already fighting for real-estate. (putting in more drivers -- each with their independent/space-consuming chassis -- may not be ideal for enclosures that are and must remain compact). Single/large-driver designs -- as in the case of the new Sony EX1000 with its single, large 16mm diapr. -- seems to have some serious advantages ... e.g., that large diaphragm can move a lot of air.
 
I, myself, tend to prefer dynamics, overall.

 

[mark2410]

arguably the more drivers the less hard each driver must work to move the air sooooooooooo there should in theory be some improvement.
 
 
however i think its mostly to pander to "more = better"
 
 
that said i think somuthing like 5 driver could be interesting, do a normal 3 way like the the UM3x and use the other 2 as a 2 way with a seperate crossover so that they both smoothly cover the crosover points of the 3 way system.

 

[TheGame21x]

I find it odd that so many multi-armature IEMs can match the detail retrieval and presentation of the single driver ER4...20 years later. 
 
I can certainly appreciate the quality of multi-armature IEMs (I still love my Triple.Fis) and I can see their virtue but it makes me think that universal manufacturers should focus on tuning one (maybe two) driver(s) for a pair of IEMs and leave the multi-armature setups to custom manufacturers.

 

[Sylafari]

IMO More BA drivers = higher price = Marketing schemes = Company Makes More Money.
Although maybe adding more drivers is the simpler solution than tuning 1-3 BA drivers extensively (Maybe crossovers easier to implement than sophisticated tuning of BA drivers). So I guess maybe its simpler to make a better sounding IEM and make more money by putting more drivers at the same time?
 
 
 

 

[ubercaffeinated]

the jump from a single BA to 4 BAs was big one for me. it satisfies me and fills me up, while retaining that neutral sound signature i'm so found of. there's just more layers to the sound than a single BA driver provides.
 
i'm sure the jump from 2-3 BAs to 4 BAs isn't as a big jump and i'm sure there is some marketing hype involved in the universal +1 BA driver wars, but it's not like a company can just shove an extra BA in a housing and make something that sounds as good as the W4 without putting some thought into it - and it's street price is still not more expensive than universals with 3 BAs (consider the umx3 rc, se535, or sm3 v2).
 
in my opinion, once you get to the > $300 dollar range for multi BA universals, (ie the W4, UM3x, SM3 v2, SE535, etc), the number of BAs shouldn't come into consideration of your purchase. 
 
you shouldn't be thinking that an extra armature would provide some "x" value more in sound quality - you should realize that you are paying for a particular sound signature that you enjoy and has obvious synergy with the kind of music you listen to.
 
 
Quote:

IMO More BA drivers = higher price = Marketing schemes = Company Makes More Money.
Although maybe adding more drivers is the simpler solution than tuning 1-3 BA drivers extensively (Maybe crossovers easier to implement than sophisticated tuning of BA drivers). So I guess maybe its simpler to make a better sounding IEM and make more money by putting more drivers at the same time?
 
 
 

 

 

[Sylafari]

Quote:

the jump from a single BA to 4 BAs was big one for me. it satisfies me and fills me up, while retaining that neutral sound signature i'm so found of. there's just more layers to the sound than a single BA driver provides.
 
i'm sure the jump from 2-3 BAs to 4 BAs isn't as a big jump and i'm sure there is some marketing hype involved in the universal +1 BA driver wars, but it's not like a company can just shove an extra BA in a housing and make something that sounds as good as the W4 without putting some thought into it - and it's street price is still not more expensive than universals with 3 BAs (consider the umx3 rc, se535, or sm3 v2).
 
in my opinion, once you get to the > $300 dollar range for multi BA universals, (ie the W4, UM3x, SM3 v2, SE535, etc), the number of BAs shouldn't come into consideration of your purchase. 
 
you shouldn't be thinking that an extra armature would provide some "x" value more in sound quality - you should realize that you are paying for a particular sound signature that you enjoy and has obvious synergy with the kind of music you listen to.
 
 


 

Yes I agree that adding an extra armature wouldn't provide some "x" value more in sound quality, on the other hand adding an extra armature does mean a higher "x" value in the price of the IEM.
 

 

[ubercaffeinated]

but are we talking about universals here? or customs?
 
if we're talking about universals, then there is hardly a difference between that 3rd and 4rd BA added in terms of price.
 
Quote:

Yes I agree that adding an extra armature wouldn't provide some "x" value more in sound quality, on the other hand adding an extra armature does mean a higher "x" value in the price of the IEM.
 

 

 

[Sylafari]

The Westone 4 is 100 dollars more than the Westone 3, imo thats a pretty big difference in price. Sure the Shure SE535 might be more expensive than the Westone 4 but thats a different company and different companies have different pricepoints. About universals or customs, I guess I'm talking about both?
 
Quote:

but are we talking about universals here? or customs?
 
if we're talking about universals, then there is hardly a difference between that 3rd and 4rd BA added in terms of price.
 


 

 

 

[bbrunskill]

I've never tried anything higher than dual driver, but I do know this. The crossovers in IEMs are R/C networks - the most simple form of crossover circuit possible.
 
And with a simple crossover like that, you get all kinds of phase shift, and harmonics and so on and on.
So IMHO, I think for simple IEM's with the most consise sound, I would prefer a two way, (single crossover) that way, there's less to go wrong.
 
The future for complex multidriver IEM's is with external digital crossovers.

 

[james444]

^ I'm lacking the technical background to judge crossovers, but among the multi-BAs I've heard there are only few that I'd consider coherent, so I guess you're right. Besides I'd think that driver selection plays an important role too, since any variance in bass/mid/treble driver signatures will also impair coherence.

 

[alphaman]

Quote:

arguably the more drivers the less hard each driver must work to move the air sooooooooooo there should in theory be some improvement.
 
however i think its mostly to pander to "more = better"
 
that said i think somuthing like 5 driver could be interesting, do a normal 3 way like the the UM3x and use the other 2 as a 2 way with a seperate crossover so that they both smoothly cover the crosover points of the 3 way system.

Yeah, "more = better" is old-school marketing psychology ... and it still seems to work. However, the comments posted in this (and similar) forums also indicate more-aware end-users (= geeks, audiophiles, etc). So the marketing psych might not always work (or even be counterproductive) ... nevertheless, it's still used . Is this because the primary customer the manuf caters to (= where the profits are) is not that critical about (interested in) the technology itself (i.e., they only go by their ears) ??? Hence (warning: wild speculation ...), the more=better theory is placebo effect or cognitive dissonance or psychosomatic? Maybe, Tyll and InnerFidelity can be talked into another double-blind test. LOL. 
 
IAC...
Not sure what may be considered "hard work" at this mass-driver scale. A v. crude analogy may be how much more mass a beetle can move compared to a human. 
 
Perhaps the single most important technology that made high-performance IEMs/ear buds possible is the powerful neodymium (Nd) magnet. Using it, you can scale way down to the "micro" (in-ear) level (and/or use their powerful MGOe for necessary apps in computer HDs and hybrid car components ... or beyer Tesla full-sized cans. Note: I realize that Nd is used quite ubiquitiously in the industry -- even for cheap cans. But like all things in the modern era, Nd mags have been steadily improving -- and there are better (= pricier)  "grades" for more-critical apps). While modern Nd's can offer relatively high MGOe at small sizes, the size still matters ... bigger=more powerful. This is why I earlier remarked about all the room taken up by the separate housing elements of BA modules, as shown here...
 

The metal chassis may also pick up EMF/RF and can itself induce EM distortion . Does an IEM designer want to fit a bunch of these into a space-limited chassis? Or simply settle with one or two well-designed units (BA or dynamic) with large, high-MGOe Nd magnet(s)?
 
IEMs with several BA drivers -- as shown above -- may indeed sound better for reasons unrelated to the quantity used. The obvious -- quality -- is one. Some one mentioned tuning ... for sure: tweak the electronics math and play around with driver positions enough (i.e. invest time into the project) and read all our feedback (forums, blogs, review sites) and tweak/tune some more ... and bingo: "Man, that latest $2,000 8-way Ear-fi custom sounds awesome". "Get your own."

 

[Xymordos]

I thought the most detailed IEMs were ER4, 2X-s and UERM?