The 3-Way Classic Part 4.
As I went back to my initial simulations I discovered a horrible ERROR. The tweeter in the simulation is fed a full range signal.
It is supposed to be fed from the active high-pass filter as in the simulation below. Oops, not good! My initial assumption that the less sensitive SB12NRX25-8 would be enough just proved wrong and I now fully understand why Troels went with the SB12MNRX25-4.
The 3/4-inch SB21RDC-C000-4 still seems to work based on the simulation, but the SB12NRX25-8 is better replaced with the SB12NRX25-4 or the SB12MNRX25-4. I personally went with the SB12MNRX25-4.
Time to put things together and measure. I used REW according to Kimmo Saunisto's document VituixCAD_Measurement_Preparations_REW.pdf except for near field measurements where I used the analysis option "set window widths automatically" to get below 200 Hz. I took far field measurements -45 to 45 degree angles in 15 degrees increments. I did not use an SPL meter so please pay no attention to the absolute position on the dB scale.
Note: the measurement results has been updated with more accurate results after this post was first published.
This is how the tweeter SB21RDC-C000-4 measured.
And this is how the woofer SB23NRXS45-8 measured.
And finally the near field measurements of the port and the woofer SB23NRXS45-8.
This is how the woofer SB23NRXS45-8 measured.
And this is how the port measured.
Next step was to use the VituixCAD Merger tool to merge near field measurements with far field measurements. I used the VituixCAD Diffraction tool to provide the near field measurements with a baffle diffraction response. I then loaded the measured and merged data into VituixCAD.
This marks the end of the fourth part about my 3-Way Classics. The next post will be about the passive filters...
