Balanced vs unbalanced

[Blashyrkh]

The angle is almost negligible. It would be comparing to speakers from the sides of the head to 2 speakers a few degrees more forward. Still on the side of the head and far removed from sounds coming from the front. When you look at measurements of HATS with the response plotted at different angles you will see there is very little difference there.
That, however, is not the same as a driver being close to the ear. Drivers have a different response from the middle and towards the edge (when measured up close) and positioning is more important than an angle being slightly different.
So this is a complex thing not easily measured nor captured in numbers or visualizations.


Plenty of research is done on this. Variations can be up to 20dB (narrow band) above several kHz.
The whole 'soundstage, depth and imaging' is very individual dependent and the combination of headphone/fit/interaction.
There is no way you can capture this in a number, plot or visualization that will be correct for the majority of people (think Harman target for tonality)



All drivers are balanced in operation. It is only about the voltage across the driver. Differential drive or not does not matter at all as the voltage across the driver is the same.
So IF there are actual differences they would have to come from an increased output resistance (it is always double in differential mode) or it has to do with 3-wire versus 4 wire.
There could be situations where the common (ground = sleeve) connection in the amp itself has an unusual high (think several ohms) between the sleeve contact and the reference (common/signal ground) combined with low impedance headphones.
With most amps the sleeve connects directly to a ground plane though.
There is no magic or special something between differential and SE drive that is so different that it would not affect tone or stereo effects but only imaging.
Of course, a 6dB level difference (double the voltage) when switching between a SE and balanced output can bring effects that would be really hard to ignore unless one also lowers the level exactly 6dB when switching between the 2 outputs. When the 'balanced connector' is just for convenience a direct comparison would make more sense and would be easier to do.
Or you should be able to separate that single aspect and be able to tie that to the actual signal that is very different.

Thanks for the answers, I got few new more notions.

Just about the volume, the increased 6db is too much of a difference, and I think the first thing to do when comparing is matching the output.
But it's not how I intend to test, since I care about diffenrences only noticable during a normal relaxed session where I can raise or drop the volume on different songs to my usual listening volume.

Anyway isn't there a possibility (probably related the increased output res and the 4 wire) that the higher output voltage may help piloting the transducers for high variable impedance headphones?

 

[solderdude]

Anyway isn't there a possibility (probably related the increased output res and the 4 wire) that the higher output voltage may help piloting the transducers for high variable impedance headphones?

There is nothing to 'pilot'.

When the 6B difference in level is not present the voltages and currents are exactly the same.
The drivers are always balanced in operation regardless if one of the ends is referenced to ground or not.
The variance of impedance has no other influence other than drawing less current. Actually it isn't even that it technically is a counter EMF that generates a current in the opposite direction of the supplied one that are simply subtracted from each other while the applied voltage remains the same effectively lowering the drawn current and seemingly increasing the impedance.

An amplifier only provides a voltage. There is no difference whether or not this is created opposite a reference (0V) or opposite another voltage.
Besides... if it were impedance dependent balanced would not 'work' the way you think it does with planar dynamics nor with quite a few dynamics.

The only benefit of balanced drive is a higher possible max. output voltage where a power supply voltage imposes a limit.
The benefit of 4 wire over 3 wire is the most important aspect.
The common return wire which affects stereo effects/crosstalk is simply not present in a 4 wire solution.

The point is that even a TRS jack (which by definition has 1 combined reference) can still make perfect use of a 4 wire 'solution' even when the headphone itself has a single side entry. As long as that has 4 connections on the headphone side it will work just as effectively as a differential drive.
This is because the drivers are inherently 'balanced' in operation.

 

[Blashyrkh]

There is nothing to 'pilot'.

When the 6B difference in level is not present the voltages and currents are exactly the same.
The drivers are always balanced in operation regardless if one of the ends is referenced to ground or not.
The variance of impedance has no other influence other than drawing less current. Actually it isn't even that it technically is a counter EMF that generates a current in the opposite direction of the supplied one that are simply subtracted from each other while the applied voltage remains the same effectively lowering the drawn current and seemingly increasing the impedance.

An amplifier only provides a voltage. There is no difference whether or not this is created opposite a reference (0V) or opposite another voltage.
Besides... if it were impedance dependent balanced would not 'work' the way you think it does with planar dynamics nor with quite a few dynamics.

The only benefit of balanced drive is a higher possible max. output voltage where a power supply voltage imposes a limit.
The benefit of 4 wire over 3 wire is the most important aspect.
The common return wire which affects stereo effects/crosstalk is simply not present in a 4 wire solution.

The point is that even a TRS jack (which by definition has 1 combined reference) can still make perfect use of a 4 wire 'solution' even when the headphone itself has a single side entry. As long as that has 4 connections on the headphone side it will work just as effectively as a differential drive.
This is because the drivers are inherently 'balanced' in operation.

thanks again for the explanation