the DPA d:vice has an "80 Hz second order highpass filter", thats all the spec given, no slope
from what i gather, 80 Hz is where it should be 3 dB down. does "second order" tell us anything about the slope? trying to model with graphic EQ in soundforge to hear what it should sound like
2nd order tells us 12dB/oct
so -3dB at 80 Hz, -15 dB at 40 Hz, -28 dB at 20 Hz?
Roughly. There are some other factors affecting initial slope that might render slight differences, but shouldn't be much.