Hi All;
One thing that I just learned (by screwing up and then fixing it) was that when you implement a baffle step correction filter you should use a high shelf with negative gain rather than a low shelf with positive gain.
I needed a baffle step correction at 400Hz. I had originally used 5-6dB with a turnover at 400Hz with a Q of 0.5 (that value was estimated). This means that at low frequencies there is 6dB of gain applied; at 400Hz there'd be 3dB and by the time you get to 1kHz there's be less than 1dB and eventually 0dB for the rest of the spectrum.
I did this and the bass improved as expected. Measurements were flatter and I was happy with the result. On some recording however (Pat Metheny One Quiet Night or Strawbs Hero and Heroine) there was significant distortion in the low frequency range. It was not present on all recordings but these two were awful.
Did a lot of thinking and on a hunch changed the filter from this FR_Before to FR_After; executing the two files side by side and and compensating for the gain (adjusting the volume control) and the distortion was gone.
So at least in this application attenuation seems to be better than gain.
I hope that this helps some people.
I have attached the Audio Weaver file.
Cheers
Matt
3way_800_2k5_vc_2021_10_18_canned3.awd
One thing that I just learned (by screwing up and then fixing it) was that when you implement a baffle step correction filter you should use a high shelf with negative gain rather than a low shelf with positive gain.
I needed a baffle step correction at 400Hz. I had originally used 5-6dB with a turnover at 400Hz with a Q of 0.5 (that value was estimated). This means that at low frequencies there is 6dB of gain applied; at 400Hz there'd be 3dB and by the time you get to 1kHz there's be less than 1dB and eventually 0dB for the rest of the spectrum.
I did this and the bass improved as expected. Measurements were flatter and I was happy with the result. On some recording however (Pat Metheny One Quiet Night or Strawbs Hero and Heroine) there was significant distortion in the low frequency range. It was not present on all recordings but these two were awful.
Did a lot of thinking and on a hunch changed the filter from this FR_Before to FR_After; executing the two files side by side and and compensating for the gain (adjusting the volume control) and the distortion was gone.
So at least in this application attenuation seems to be better than gain.
I hope that this helps some people.
I have attached the Audio Weaver file.
Cheers
Matt
3way_800_2k5_vc_2021_10_18_canned3.awd