Closed-Loop Amplification with Driver Cone Position Fedback

[CharlieLaub]

Do you suppose your matrix of photodetectors will have and order of magnitude less distortion (that is, will be more precisely linear) than a $200 woofer that is the product of 75 years of ardent development to make it linear?

In short, yes. That's why I proposed this here.

 

[CharlieLaub]

the problem with such photo-sensors would probabely be to achieve a sufficient dynamic range -or, the other way round- sufficient resolution.

This is true, one must be concerned with resolution. But I have seen some recent data that seems to suggest that these photoresistors are quite linear for the middle 90% of their range. This is why I proposed an overlapping array of 2 or more columns/rows. This should help to average out the nonlinearities and provide increased resolution.

 

[bentoronto]

Light has some nice qualities (light weight, fast...) and easy to speculate about using it. But the complexities of controlling it in a highly linear fashion (linear enough to reduce the distortion of a driver) and tied perfectly to the motion of a vibrating piece of cardboard that can move an inch in-and-out, are very great.

Ben

 

[DUG]

For any type of feedback sensor:

What should the bandwidth of the feedback system be?

Let's normalize on 100Hz output from the sub.

 

[DUG]

CharlieLaub

CdS photoresistor detectors are too slow...35mS typical rise time or more.

Had an idea last year...wedge sliding across an OPT101

PHOTO DIODE SIZE: 0.090 x 0.090 inch

Enough light and a fast bandwidth...low gain.

Have not tried it yet...need to find my micrometer for measurement.

It is on the list.

🙂