[belushka]

What's the advantage of multi BA over single BA if there is any?
Bigger frequency range? Better response?

 

[tomscy2000]

Mostly bragging rights.

 

[tzjin]

This thread. http://www.head-fi.org/t/621482/why-not-a-dual-ba-from-etymotic
 

 

[tinyman392]

Quote:

What's the advantage of multi BA over single BA if there is any?
Bigger frequency range? Better response?

 
There really is no advantage in my mind.  There are theories, but I don't see any of them as a full truth.  

 

[Inks]

There is possibility of greater treble bandwidth. Doesn't mean all multi-BAs have better treble bandwidth but they potentially can. B2s for example have greater treble bandwidth than every tested single BA i've seen. But certain multi-BA IEMs like the Shure SE535/425, XBA-2, SM2, etc. Have even less treble bandwidth than a single BA ER4S or PFEs. 
 
Though in the end, the treble bandwidth superiority will be very small. ER4S goes up to 17k, PFEs to 19k the B2's superior treble bandwidth goes higher than 20k, but 20k is already pushing the hearing limits on many. 
 
Better response or "resolution", nope no advantage. I think placebo and bias play a role here. 

 

[tzjin]

I think also its the ability to tune the sound. If you want more bass, just add another driver.

 

[Inks]

That is a thing to consider. With a single BA it seems the manufacturers are more limited in their tuning possibilities in terms of making a unique sound. With multi-BAs you can make a more unique sound Not an advantage in terms of performance though, just more possibilities. 

 

[belushka]

but all single BAs I've seen have smaller frequency range, usually just up to 10 kHZ and then they rapidly fall. Well ER4P are better but have weaker bass response in return. That's what I've seen from frequency graphs. I am talking about XBA-1 and Philips SHE 9850 for example...
 

 

[ishmael]

Quote:

That is a thing to consider. With a single BA it seems the manufacturers are more limited in their tuning possibilities in terms of making a unique sound. With multi-BAs you can make a more unique sound Not an advantage in terms of performance though, just more possibilities. 

 
This is a good point. 
 
I also agree with the other person who said that single BA designs tend to sound the same. At least to my ears they do. I'm sure there are some that don't though. 

 

[tinyman392]

Quote:

but all single BAs I've seen have smaller frequency range, usually just up to 10 kHZ and then they rapidly fall. Well ER4P are better but have weaker bass response in return. That's what I've seen from frequency graphs. I am talking about XBA-1 and Philips SHE 9850 for example...
 

 
Many do...  But there are others that do hit the maxes.  I think 10 kHz is a huge understatement.  Etymotic hits around 16 kHz.  MEE's A151 hits 18 kHz...  MEE's A161 does 20-20...  UE's 600s doe 20-20 as well.