A textile dome isn't going to require a notch. Its really only the Ti, some Alu and Mg domes. Be is usually well behaved due to its higher internal dampening, depending on geometry of the dome.
I'd only employ a UHF notch if the peak was more than a few dB. Problem is you're relying heavily on supplied data that may not be so accurate and the only way to know for sure is with measurements. That means you need a mic that goes at least to 30k - not cheap. Again, easiest way to know is with an impedance sweep. The amount of notch is important, because you don't want to remove all the energy up there, just enough to flatten it out.
My favorite Ti dome is the Audax TW025A28, which ironically has a severe measured peak of more than 10dB around 26k (ouch). Likely the product of the catenary dome shape they use. I did an experiment with my son listening and didn't tell him I was switching the notch filter in/out. He could tell immediately when the peak was there, so could I with my 50+ year old ears. Without the notch, cymbals sounded etched and had some distinct harshness to them. With the notch, treble sounded like it was coming from electrostats or ribbons.
I'd only employ a UHF notch if the peak was more than a few dB. Problem is you're relying heavily on supplied data that may not be so accurate and the only way to know for sure is with measurements. That means you need a mic that goes at least to 30k - not cheap. Again, easiest way to know is with an impedance sweep. The amount of notch is important, because you don't want to remove all the energy up there, just enough to flatten it out.
My favorite Ti dome is the Audax TW025A28, which ironically has a severe measured peak of more than 10dB around 26k (ouch). Likely the product of the catenary dome shape they use. I did an experiment with my son listening and didn't tell him I was switching the notch filter in/out. He could tell immediately when the peak was there, so could I with my 50+ year old ears. Without the notch, cymbals sounded etched and had some distinct harshness to them. With the notch, treble sounded like it was coming from electrostats or ribbons.
Hi thanks for the answer, i have not done impedance measurements before, only frequency (im beginner).
Can i do impedance sweep that will show possible problems over 20k with Lineaudio om1 mic, (frequency: 20-20 000Hz) or:
-Do i have to try to loan from local diy forum a mic with capabilities to 30k?
You can do an impedance sweep with a sine wave generator and 100 ohm series resistor, measuring voltage drop. That will at least tell you if there's a problem above 15k which you can't tell just by listening during the sweep.
If you want accuracy, a good 30k+ capable mic is the only way to proceed for reliable data. Cheapest mic i know of that will pick it up is the Audix TM1 ($300 with cal file), but it won't be linear up past the low 20k area. Something like an Earthworks M40 or better would be good IMO.
If you want accuracy, a good 30k+ capable mic is the only way to proceed for reliable data. Cheapest mic i know of that will pick it up is the Audix TM1 ($300 with cal file), but it won't be linear up past the low 20k area. Something like an Earthworks M40 or better would be good IMO.
I say try it with and without an LP on the tweeter. I built some two ways with a Fountek ribbon and I didn't like the rising output above 10khz so I added a 100uH inductor after the high pass. I went back and forth with it and without it when testing. To my old ears it sounded pretty much the same either way, but I assume my dog is happy with the inductor in circuit so I left it in. Here is my schematic along with the predicted responses, you guess which is which.
