terryforsythe
Major Contributor
- Thread Starter
- #21
I just went back and studied all of the harmonic distortion data that I have in more detail. I hypothesize that the passive crossover used in the stock speaker had the effect of moving the midrange's HD peak from about the 150 Hz frequency in my measured data to the 220 Hz frequency shown in Erin's data. Since I am not using a passive crossover, that shift is not happening.
At about 320 Hz you can see the harmonic distortion getting above the noise floor in my woofer data, though. The DSP is affecting it somewhat, and it peaks at 372 Hz in my 86dB/1m distortion measurement.
The other aspect of these measurements worth noting is that the midrange's harmonic distortion primarily is 2nd harmonic. From about 260 Hz to 410 Hz the woofer's harmonic distortion primarily is 3rd harmonic, which tends to be harsher than 2nd harmonic distortion.
I gave consideration to shifting the woofer/midrange crossover frequency down to 350 Hz to see if I would tame down the woofer's 3rd harmonic distortion before the midrange's harmonic distortion begins to have a significant affect. However, after going back and looking at Erin's response linearity data (again, Erin's Audio Corner - check it out if you haven't, it is a great website - https://www.erinsaudiocorner.com/), I think that would be counter productive. In fact, after reviewing Erin's data, I may bump up the woofer/mid crossover point to 500 Hz. Here is Erin's graph:
At about 320 Hz you can see the harmonic distortion getting above the noise floor in my woofer data, though. The DSP is affecting it somewhat, and it peaks at 372 Hz in my 86dB/1m distortion measurement.
The other aspect of these measurements worth noting is that the midrange's harmonic distortion primarily is 2nd harmonic. From about 260 Hz to 410 Hz the woofer's harmonic distortion primarily is 3rd harmonic, which tends to be harsher than 2nd harmonic distortion.
I gave consideration to shifting the woofer/midrange crossover frequency down to 350 Hz to see if I would tame down the woofer's 3rd harmonic distortion before the midrange's harmonic distortion begins to have a significant affect. However, after going back and looking at Erin's response linearity data (again, Erin's Audio Corner - check it out if you haven't, it is a great website - https://www.erinsaudiocorner.com/), I think that would be counter productive. In fact, after reviewing Erin's data, I may bump up the woofer/mid crossover point to 500 Hz. Here is Erin's graph: