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Are all amps being built wrong?

The power amplifiers that drive our loudspeakers are mostly built as a low impedance voltage source. They have always been ... but why?

Loudspeakers have a (greatly) varying impedance over the frequency range. A current drive amplifier would eliminate the issues that stem from this varying impedance, and at the same time make discussions about esoteric speaker cables that strive for optimal R, C, L superfluous. Although there still would be these un-measurable ’this (very expensive) cable sounds better’ debates and opinions ... and that’s OK, that’s part of the fun. :)

So ... why are amplifiers not built as a high impedance current source?

This is an interesting read: https://www.current-drive.info/
rudyb
holmz's avatar
holmz
2,328 posts
 
If one was to use a DSP, then (I think that) all gets normalised to be right whether using a voltage or current source?


Room correction in modern systems would be doing the same thing I think.
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atmasphere's avatar
atmasphere
11,640 posts
 
Speaker drivers are designed to work best when fed with a voltage source.
**Most** are but some are not. ESLs for example...
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holmz's avatar
holmz
2,328 posts
 
Speaker drivers are designed to work best when fed with a voltage source.

I am only sure that this is true is the impedance is flat.

Since the equation for magnetic flux is based upon current, then one could argue that it is the current that is producing the force in the motor.

Speakers which means drivers and crossovers are also designed to work properly with a voltage source.

There are advantages and disadvantages of driving a speaker driver with a current source or a hybrid but to make it work the overall speaker must be designed from the ground up for it.

^That^ is a statement, and sounds like an opinion.

No DSP is not a substitute. It has to happen at the driver/amp interface.
Anything that linearises and equalises the output makes for a more linear system. (Yeah it’s a tautology) However if the speaker was a constant impedance and the, then it would play flatter. You can alter the incoming signal’s voltage so that it plays flatter out of the speaker as a system. One can do this for both current source or voltage source amplifiers and end up with a flatter speaker response curve.

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