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2-Way Crossover Design

tanno1

Member
Joined
Aug 30, 2024
Messages
25
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Location
seattle
Hey all,
As per previous posts, I am building a crossover for a 2 way desktop speaker.
I am following this paper by TI: https://www.ti.com/lit/ug/tidu035/t...69574&ref_url=https%3A%2F%2Fwww.google.com%2F. I got up through the Low Pass filter, using some amplitude vs frequency data for my woofer that I extracted using VirtuixCAD and some numerical solvers I made in python to determine optimized component values.

The first step was the baffle compensation. Using my uncorrected woofer data, I came up with this optimization for my baffle step compensator and got values R17=R15=R16=10kOhm, and C15 = 1e-07F. These values are somewhat close to what the TI paper has for their design, but I would like to check with the community and see if I am on track.
View attachment 415170
1734667753198.png

For the low pass filter, I basically did something similar. I aimed for a cutoff frequency of 1.8khz, but since I have to account for the actual driver response, a similar numerical solver calculated 2200Hz for my corner frequency for my 4th order Linkwitz-Riley crossover. As you can see in the image, I adjusted the gain of my acoustic transfer function to be 3 dB higher because it lined up better with the filter response. Taking that to FilterPro, I forced the C2 value to be 100nF based on advice from the TI paper on increasing C value to decrease R values and decrease thermal noise.
1734668076712.png
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My main questions here:
1. am I missing anything obvious
2. Do I need to flatten or attenuate this woofer signal at all? the 5db-ish variation and the spike at the end of the graph don't look great but I don't think it will affect the design because the xo will cut it off?
3. In my LPF, I added a 3dB gain to push the magnitude response up towards the filter, is that valid?

Thanks in advance, this is my first speaker design and I can't wait to one day share the final build.
 
Actually one other thing. I put in filter pro a gain of 3 dB, but in my plot, I just added 3 dB to all of my values that are plotted for the combined optimized filter and woofer repsonse. Is that valid to account for that gain in the FilterPro design? Or do I need to add a separate gain circuit before that...?
 
I also managed to get through the HPF today. I had to drop the response of my tweeter by 9 dB to get the tweeter response for this centered around 9. I am assuming that this actually might be the equivalent of boosting my amp output a bit. Now I am second guessing the bump of the HPF so hoping to get some feedback on that? I would think that the gain of the overall response is editable based on the gain of my amp so it shouldn't matter, I just need to match the waveform. Anyways, the response got me a corner frequency of 1700 for the image below, but I think I am just going to bump it up to 1800. I don't want too much of a gap between the two filters.
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Any feedback would be great. I know there are a ton of Qs in here, but I appreciate anything.
 
Vituixcad can model the whole thing including the baffle/enclosure. So you can get a look at what your current design looks like on and off axis.
 
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