Alien_Shore
04-14-2013, 11:11 AM
Calling all filter experts.
I'm working on a crossover design for a 2-way using an Altec 802-16G HF compression driver mounted on 511B horn paired with a 816 bass horn. I need a passive filter that will work for four of these 2-way enclosures. After lots of testing and measurements, I settled on a 900 Hz crossover point (seems best for the woofers I'm using). The trick here is that the compression drivers have some variance in their impedance curves (some are a little hotter than others).
One of the HF drivers has Fs at 893 Hz / Zmax 31 ohms, while another (with the same brand-new diaphragm) has Fs at 699 Hz / Zmax 36 ohms. With this variance, and both fairly near to my XO point, I felt like I really need a notch/contour filter that will accommodate these variances across the drivers. After reading a few different design books and web sites, I'm seeing different opinions on which type of resonance filter works best.
Some advocate a parallel filter (A), while others recommend a series filter (B). I've designed and prototyped the parallel filter, in the circuit below, and it sounds pretty good. But before I go to the trouble of putting together the (B) option, I thought I would check here to see if anyone has ideas, advice, suggestions. If I go with option (B), is that the correct placement (i.e., after the XO and L-Pad)? If it is, I'll have to go back and re-sim the XO values, since it will change my impedance curve...
Can anyone offer any guidance here?
http://img255.imageshack.us/img255/6891/peakfilterab.png (http://imageshack.us/photo/my-images/255/peakfilterab.png/)
I'm working on a crossover design for a 2-way using an Altec 802-16G HF compression driver mounted on 511B horn paired with a 816 bass horn. I need a passive filter that will work for four of these 2-way enclosures. After lots of testing and measurements, I settled on a 900 Hz crossover point (seems best for the woofers I'm using). The trick here is that the compression drivers have some variance in their impedance curves (some are a little hotter than others).
One of the HF drivers has Fs at 893 Hz / Zmax 31 ohms, while another (with the same brand-new diaphragm) has Fs at 699 Hz / Zmax 36 ohms. With this variance, and both fairly near to my XO point, I felt like I really need a notch/contour filter that will accommodate these variances across the drivers. After reading a few different design books and web sites, I'm seeing different opinions on which type of resonance filter works best.
Some advocate a parallel filter (A), while others recommend a series filter (B). I've designed and prototyped the parallel filter, in the circuit below, and it sounds pretty good. But before I go to the trouble of putting together the (B) option, I thought I would check here to see if anyone has ideas, advice, suggestions. If I go with option (B), is that the correct placement (i.e., after the XO and L-Pad)? If it is, I'll have to go back and re-sim the XO values, since it will change my impedance curve...
Can anyone offer any guidance here?
http://img255.imageshack.us/img255/6891/peakfilterab.png (http://imageshack.us/photo/my-images/255/peakfilterab.png/)