Quote:
Originally Posted by lowmagnet /img/forum/go_quote.gif
You made some claims above. Care to show your math to prove it?
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If you have to ask, would you guys be able to follow it? The basic idea is that the output impedance of balanced is half of the unbalanced (i want to say single-ended, but that would be reserved for the amp topology) amp, since each amp channel is only driving half a transducer whereas in unbalanced mode, it would be one amp per transducer. With half the output impedance, you get double the damping factor:
The 'damping factor' is the speaker impedance (ZL) divided by the amp's output impedance, for example 60 ohm headphone driver and 2 ohm amp output impedance:
DF = ZL / Zo = 60 / 2 = 30
With a balanced amp, the damping factor would be 60. What does this mean? Well if you know what Thiele-Small Parameters are, there is this factor called Qes, which is the electrical Q, and this value effects the bass response and varies depending on output impedance. High damping factors usually mean that the bass response will be well defined ("tight"), whereas a low damping factor will result in a loose sounding bass. If you have a high output impedance, the voltage delivered by the amp is reduced at lower load resistance, while it remains constant at high load resistance. This is true even with low output impedance, but the change in voltage in the circuit is much smaller.
From
http://www.audioholics.com/education...ked-questions:
Slew Rate: This is a term used to describe how quickly the output of an amplifier can track its input. Slew Rate is usually measured in V / usec. The higher the value (up to a point), the better the amp is at potentially reproducing the subtle nuances and dynamics associated with music reproduction.
Damping Factor: This is a quantity which defines how quickly the amplifier can stop a reproduced frequency such as a bass note. The higher the damping factor, the better the amp will control the woofer and help reduce overhang distortion (again to a point). The damping factor of an amplifier is mostly dependent on the output impedance of the power amplifier and the ability of the power supply which feeds the power amp.