Electrostats vs conventional drivers

[SY]

I think that the baffle compensation is the reason for the multiple taps. I haven't measured with anything other than the 1+1 tap, but I'll bet that the first part of the curve, the dipole-cancellation part above the fundamental resonance, is what gets raised and lowered. Of course, the load is changing too as more panels are added, which interacts with the transformer ratio....

Do try to get a couple of panels as the load- I substituted some HV ceramic caps as the load and got very different results as I approached the fundamental resonant frequency of the panels (roughly 100Hz).

[bear]

I have panels, but they were not connected to the unit.

Here are the results:

Acoustat 121a interface; no load; 0 db ref 1kHz. (measured ground/CT to one leg of the secondary, both xfmrs & coupling components used)

20Hz. +7
40Hz. +7
100Hz +7
200Hz. +5
500Hz. +2
1kHz. 0
5kHz. -1
10kHz. -1.5
20kHz. -1.5

The HF pot was randomly set by the owner of the unit (it's here for repair - hv section) so that accounts for the minus figures above 1kHz.

The unit was swept, I recorded approximate frequencies of interest... HP ACVTVM recorded the dB levels.

I also dunked in a 0.001ufd and a 0.01ufd as a load to see... no significant change was noted.

The tap was on the Model 4 setting - least "boost" via the LF xfmrs *primary* tap - I got that wrong in the earlier posts.

What's a 1/4 wave at 8"? Seems higher than 150 hz., seat of the pants...

_-_-bear

[SY]

Well, the total panel width (with overhead) is about a foot. So you'd expect to see cancellation effects centered around 400-500 Hz or so.

[bear]

Oh... I will double check probably next weekend to make 100% certain that both transformers are working - it's unlikely that they are not, but still a possibility.

_-_-bear