Ridiculously primitive to have an element in your music system with no feedback around it, esp. an element as crude as a cone-type driver (AKA waving heavy cardboard cones to make sound).
I've run circuits of this type (bridge-derived feedback) for most of the last 45 yrs and motional feedback is great in several important ways. I think bridge-derived feedback makes more sense than trying to use an accelerometer to sense motion even with today's better or more cost-effective accelerometers.
But Rice-Kellogg drivers being primitive devices, certain restrictions have to be recognized. You need to work with a suspension system that is simple and where the cone motion bears a close relation to sound output. In practice, this means sub-woofers in sealed boxes (but a Klipsch folded corner horn also has a rear-loading sealed box).
Otherwise, you need to work within the usual Nyquist criteria relating to phase. In practice, I think today that means having a DSP in the circuit to sharply curtail feedback where the phase to weird.
Beyond my grasp about whether you want velocity or acceleration sensing, but one can be readily converted to the other with a capacitor.
The loudspeaker forum at DIYaudio has more on this topic.
Ben
I've run circuits of this type (bridge-derived feedback) for most of the last 45 yrs and motional feedback is great in several important ways. I think bridge-derived feedback makes more sense than trying to use an accelerometer to sense motion even with today's better or more cost-effective accelerometers.
But Rice-Kellogg drivers being primitive devices, certain restrictions have to be recognized. You need to work with a suspension system that is simple and where the cone motion bears a close relation to sound output. In practice, this means sub-woofers in sealed boxes (but a Klipsch folded corner horn also has a rear-loading sealed box).
Otherwise, you need to work within the usual Nyquist criteria relating to phase. In practice, I think today that means having a DSP in the circuit to sharply curtail feedback where the phase to weird.
Beyond my grasp about whether you want velocity or acceleration sensing, but one can be readily converted to the other with a capacitor.
The loudspeaker forum at DIYaudio has more on this topic.
Ben
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