Hi John
Hi Chris,
Your correct, but your looking at the issue from an amplifier output impedance perspective, and thus miss my point (I dont consider the output impedance of the amplifier to be the limiting System factor) - I'm thinking of it from the "load = Air" perspective importantly the interface between electromechanical system and Air
I consider it to be a felicity to consider the damping factor of a voltage drive amplifier which should be sub ohms when the voice coil itself has such high impedance its this voice coil impedance that limits the control of the driver / air interface.
When the speaker cone is accelerated its the resistance of the voicecoil that prevents the amplifier to 100% accurately Brake the cone movement, and reverse direction etc
Consider if the voicecoil had zero impedance (and zero amplifier output impedance) there would be perfect control of the speaker drivers cone.
I guess the impedance match between a non-hornloaded speaker cone and air to be so poor that its the Mass of cone (the Cone's momentum energy) that the voicecoil impedance struggles with (simple terms impedance = resistance)
The Amplifiers output impedance is normally atleast a magnitude or two lower then the impedance of the voicecoil, so I consider it must be the voicecoils impedance that is ultimately the limiting factor when considering the "accurate control of air movement"
you seem to be making 2 points, and they shouldn't be mixed because they're not interrelated. I didn't miss your point about drive unit to air, I ignored it because it has no bearing on amplifier bridging.
When an amplifier is operated in bridge mode, it appears to be driving 1/2 the normal load impedance this must also mean an EFFECTIVE halving of the voice coil impedance (resistance) and then I suggest this results in better damping of the driver (as the voicecoil impedance limits the system damping).
I could be wrong as Ive never seen this mentioned but it makes sense to me unless Ive missed something (which really could be the case as Im no speaker driver expert)
By "System Damping / Damping" I mean to describe the accurate Control of air movement via the speaker cone, acceleration and overshoot etc.
No. Each amplifier sees (seems to be driving) the output impedance of the speaker
plus the output impedance of the other amplifier.
In a bridged amplifier there is no 'reference to zero'. Instead, as far as each amplifier is concerned, whereas on it's own it is driving to zero, it is now driving to a floating terminal - which could be zero, 90deg out of phase, 180deg out of phase and twice the amplitude - anything.
If we tweaked our bridged amp so that one amp always held its output terminal at zero, the overall output signal would be the same as our 'free running' bridged amplifier. And once again the single, active half of the circuit sees the same load as before - the speaker
plus the output impedance of the other amplifier
You have to look at the electrical circuit from the point of view of the electrical load. It doesn't know what type of amplifier is connected to it. With a bridged amplifier it sees the same voltage/current as it does with a single amp, but it sees it coming through twice the output impedance.
Whatever the amplifier topology or circuit technique, once it's connected to the load it becomes one big simple amplifying block again.
When bridged it is driving exactly the same speaker load, not half the load
This is nothing to do with the behaviour of the speaker driver
I dont wish to take this thread too far of subject
Off subject? Does this thread have a single topic? It's one of the most wandering threads ever
. Yes, this should be in a separate thread, but we've started, so we may as well continue?