BALANCED HEADPHONES? Why?

[Jim Shaw]

Dynamic headphone drivers are inherently balanced. Should be no big deal to get the cable for them right.

No, they are not. The cable doesn't change the basic electrical character of a headphone which has but one winding. The elements of the driver (and a cable) do. A balanced cable could be attached to a typical dynamic driver through a transformer. That could provide a balanced cable transmission, but not a balanced dynamic element. A balanced element would have two voice coils (or such drivers), each connected to a balanced-with-a-neutral cable, connected to a balanced output. THIS would do what some think they get from a balanced system - noise and distortion cancellation by opposition.

I don't know of any such headphones with true, balanced drivers, do you? But it would be interesting to try out.

 

[egellings]

By "balanced", I was not referring to how the drive mechanism works to produce sound in the headphone. I was referring to the simple electrical connection to a 2-terminal device. As an example, if a 'phone has a single voice coil, that is a floating electrical motor with just 2 electrical connections. I can drive that load either differentially, or with one end at ground (0Vac) with the other end receiving the drive signal. A floating voice-coil is therefore balanced by nature, but can be driven by either a balanced or ground-referenced source. The coil won't know the difference.

 

[MDNSC]

An answer From Austrian Audio.

 

[solderdude]

It look like Johann Redl made a small mistake.

The effect will be more drastic with lower impedance headphones than with higher impedance ones (Ohm's law).

Also this will only be the case with 3-wire headphone cables.
4-wire cables (with the return wires only connected in the plug) would be best. Sennheiser and most dual entry headphones do just that and is basically as good as balanced (depends a bit on the amp in question though).

 

[Dismayed]

My unbalanced system sounds fine. The background is dead quiet and it produces what sounds like music.

 

[Deleted member 58722]

Bi-amping speakers can be considered a kind of balanced speaker I guess.

My power amp has balanced outs.

 

[egellings]

I think that for home audio, both balanced and unbalanced approaches will sound good and be indistinguishable from each other. Balanced operation will definitely help in studio and other applications needing long signal cable lengths.

 

[jwmitchell]

Bi-amping speakers can be considered a kind of balanced speaker I guess.

I think balanced headphone drive is mostly a desire to have some magic to believe in. The purest expression of this is the faith that more expensive wires including mains wires are better in an audible fashion. Neglecting, of course all the low cost wiring all the way back to the power company! Not even to mention isolation transformers and other components completely dwarfing any possible improvement from a 2 m mains cable! However, if a person wants to believe and has the wherewithal then they can invoke any witchcraft they like.

 

[solderdude]

Differential headphone drive is only really interesting for creating double the output voltage (quadruple the output power) when only a certain amount of power supply voltage is available. Think portable devices.

A benefit, for low impedance headphones, is that the cable is 4-wire and this could, with some cables, have an effect on stereo imaging.

It does seem to be presented as 'magic' though.
'Balanced' is great for interlinks where is has a purpose (and better quality connectors).
Balanced does nothing for headphones as there is no ground loop, the signal is not degraded by interference from external sources as the impedances involved are too low.
Differential (not exactly the same as balanced) can be beneficial for headphones that need a bit more voltage.
The driver does not care if the signal is differential or not. It receives the same voltage and waveform.

Witchcraft it is not but many seem to believe it is. More available output power (max. SPL) and in some cases the 3-wire cable can make an audible difference feeding the idea that witchcraft/magic is somehow involved.