Headphones - balanced armature - what is it?

[AlmaataKZ]

I see in descriptions of some (in-ear?) 'phones that they have so called balanced armature. What does it mean?

What exaclty is balanced here? balanced with/against what? what is armature here? I see it mainly mentioned with multi-driver 'phones - is it becasue only the advanced modles have hte balanced armature or becuase it is only a feature of multi-driver 'phones?

 

[idc]

It means "is your chair about to fall over?"

 

[idc]

Er, I was expecting my witty comment to have been followed up with a serious explanation, so....you have a rod and a magnet and some other bits and you pass electricity through one bit....oh ****** it........clicky

 

[AlmaataKZ]

yes, thanks. I bumped into this clip also - it comes up top in google for 'balanced armature'. I thought it was quite a messy explanation in the clip with unclear drawings and comment.

I did some more reading and basically balanced armature is a type of electrodynamic acoustic transducer. it is different from moving coil type (where the coil is attached to the diafragm. the coil moves in the constant magnetic field of a magnet when alternating current goes through the coil and that moves the diafragm in line with the signal, creating sound).

'balanced armature' - the coil is not directly attached to the diafragm. the coil's magnetic filed induces current in a conductive rod (armature) which is placed around the coil and also in the magnetic field of a constant magnet. the field of the current in the armature intereacts with the field of the magnet and the rod oscillates in line with the signal (the armature is 'hanging' in the magnet's field and inside the coil, hence 'balanced' name). this armature thing is also linked to the diafragm via another rod, so diafragm produces sound.

I thought it may be some mounting system for drivers, but it is in fact a different type of electrodynamic driver.

 

[idc]

How do they make it so small?

Image it is your job to fit the armature into that. Threading a needle would be like driving a bus through Marble Arch in comparison.

 

[AlmaataKZ]

indeed, and there can be 3 of these driver assemblies inside one in-ear unit! well, I understand this type of driver has had most use in hearing aids, which are sometimes even smaller!

my current in-ears are falling apart slowly so I am getting ready to get some new ones, looking around a the moment...

 

[idc]

Have a read of my review of the Radius DDM in the headphone part of the forum, the only IEMs I have tried. When yours do fall apart, open them up under a microscope and find how they did it for me please!

 

[AlmaataKZ]

the current ones are apple in-ears. I think they are dual driver but do not think they are balanced armature.