Open Baffle Planar servo sub speaker project

[HAL]

For those wondering about digital crossovers and their differences to passive crossovers, here is a white paper from me to start discussions.

You've made a major mistake by ignoring the DCR of the speaker, which is still relevant even with a single driver.... Also, you make no case for a digital active crossover being superior to an analog active crossover. This will probably get enough responses that it should have it's own thread.

Roscoe

Roscoe,
I believe that is why Damping Factor is referenced to the 8 ohm load. Really, the magnitude of the load impedance, where the imaginary part of the impedance is ignored. So the 8 ohms refers to the magnitude of the DCR, inductance and capacitance of the load impedance in ohms. Once you divide it by the source impedance magnitude in ohms it becomes dimensionless.

Best that I understand it.

Rich

[HAL]

Second baffle complete and #4 screws arrived.

Now waiting for the second batch of correct drivers from PE. No tracking info yet.

Will be testing the first one soon.

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[HAL]

First line array is completed and ready for response measurements. Will setup Pocket CLIO tomorrow into the dspMusik digital crossover for the testing.

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[HAL]

First CLIO Pocket measurement of the FPS array without the servo subs. With some simple shelving filters should be able to flatten out the HF response of the array.

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[HAL]

Figured out the MIC-02 cable was not working correctly, so switched over to a new mic cable and my CLIO Standard 8.5 system for measurements. Now it's better!

Here is a comparison of the FPS line array with the beamformer. The red plot is the beamformer off and the green plot is with the beamformer on. About 5dB of gain at the low end with the beamformer running. I did not select FPS drivers for sensitivity matching, so that might make it a little better.

Net step is to try some absorption material on the baffle to see if the surface reflections can be tamed. Felt or foam has worked well in the past, so will try some and see what happens.

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[SoundMods]

Try some cut pile carpeting -- it is not reactive like foam and performs better lower down in the upper mid-range than felt.

You won't be disappointed.

[HAL]

Ok, will see if I have some remnants around to try.

[SoundMods]

Most flooring stores have remnants so that you pick something with a short dense pile.

[tomp]

It would be interesting to see the results with just one driver connected instead of the array. Start simple. It will give you info.

Tom

[HAL]

Did not do a single driver, but here is the center pair of drivers. No time delay difference between them, just direct drive from the HP filter. Looks very similar, just lower in level in the LF end.

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