Looking good. I'd raise the tweeter about 2dB, and lower the tweeter high-pass to 2.8k. Leave the mid low-pass where it is. The dip around 1.8k should fill in a little as you do this.
You might go as low as 2.5k on the tweeter. The mid can stay at 3k. It's not at all unusual for that to be the case, because of driver responses.
Actually, just change the tweeter x-over point, and don't add the 2dB. That will probably be better.
You might go as low as 2.5k on the tweeter. The mid can stay at 3k. It's not at all unusual for that to be the case, because of driver responses.
Actually, just change the tweeter x-over point, and don't add the 2dB. That will probably be better.
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Without a full set of polar measurements, you will not be able to calculate the power response, either with VituixCad or any other tool. You would need to construct some sort of turntable so you could rotate the speaker in 10 or 15 degree increments, while maintaining nearly exact distance from driver to microphone. You would also need to feed VituixCad the quasi-anechoic responses, and this means time-windowed scans which are merged with the nearfield scan.
Honestly, I would not bother at this point. Polar scans are more of an advanced skill. At this point, concentrate on getting a good accurate on-axis frequency scan.
Honestly, I would not bother at this point. Polar scans are more of an advanced skill. At this point, concentrate on getting a good accurate on-axis frequency scan.
I think you are ready to measure again. Whole speaker. Gated. Low SPL.... Remember, you have boosted the bass!
I'd sweep from 100hz up.
I'd also sweep just the woofers near field. Lower the spl.......About an inch from dust cap. This will show the roll--off, and approximate f3, etc. Sweep from 30hz to about 1k. Should be down a lot by 1k..
I'd sweep from 100hz up.
I'd also sweep just the woofers near field. Lower the spl.......About an inch from dust cap. This will show the roll--off, and approximate f3, etc. Sweep from 30hz to about 1k. Should be down a lot by 1k..
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yeah, good luck with that. I have never figured out how to do it.
I model a Linkwitz Transform using a 2nd order shelf filter. I never use the canned LT filter with Fo/Qo/Fp/Qp, because HFD does not have a corresponding filter.
j.
It's called Asymmetric shelf, it's one of the drop downs. Choose a lowshelf, then plug in the zero and pole frequency and Q from your simulation.
Turns out it does... it's called asymmetric shelf. Thanks @Busdriver02.
That said, I find it more intuitive and straightforward to use a 2nd order low shelf of known Fc, Q, and gain. If necessary, a PEQ can also be used in the region above Fc.
Here is how I do a L-T bass eq using a 2nd order shelf filter. Like most EQ, it is done visually to get it within about 1 dB of perfect. Final voicing is done by ear. I am not an expert, but this process works well for me, and it is fast and easy to understand.
This is an 8" woofer in a sealed box. The response is 4-pi equivalent quasi-anechoic. However, the L-T process would be the same if I was using near field (2-pi) response as the starting point.
In this case, I wanted to limit my bass EQ to 8 dB. So I looked to where the response was 8 dB down from the 200 Hz level, and it came to 45 Hz. So I know I will need about 8 dB of boost at 45 Hz, but what I do not know is what the shape of that boost needs to be.
I start by applying a low-shelf filter at 45 Hz with a gain of 8 dB. I start with a very high Q of 2.
However, I now realize that the VituixCad simulation is set to "analog" type DSP setting, and I need to set it to "Hypex FA-192k". I do this in the options tab.
When I set the simulation to Hypex FA-192k, the peak drops down to 35 Hz, so I need to adjust the Fc of the filter up until the peak comes back to 45 Hz. It turns out the value that works is 57 Hz. This is why I start with a high Q... it makes it very easy to see where the actual effective Fc of the filter is
Here I have lowered the Q down to 1, and we are getting closer to a good response.
Now the Q is lowered to 0.614, and this response looks very nice. F3 is about 41 Hz, and F10 is 22 Hz.
Here is the resulting filter gain. It is very close to what an optimized asymmetric filter (or L-T filter) would be, but for me this is easy to manually set up and control.
j.
This is an 8" woofer in a sealed box. The response is 4-pi equivalent quasi-anechoic. However, the L-T process would be the same if I was using near field (2-pi) response as the starting point.
In this case, I wanted to limit my bass EQ to 8 dB. So I looked to where the response was 8 dB down from the 200 Hz level, and it came to 45 Hz. So I know I will need about 8 dB of boost at 45 Hz, but what I do not know is what the shape of that boost needs to be.
I start by applying a low-shelf filter at 45 Hz with a gain of 8 dB. I start with a very high Q of 2.
However, I now realize that the VituixCad simulation is set to "analog" type DSP setting, and I need to set it to "Hypex FA-192k". I do this in the options tab.
When I set the simulation to Hypex FA-192k, the peak drops down to 35 Hz, so I need to adjust the Fc of the filter up until the peak comes back to 45 Hz. It turns out the value that works is 57 Hz. This is why I start with a high Q... it makes it very easy to see where the actual effective Fc of the filter is
Here I have lowered the Q down to 1, and we are getting closer to a good response.
Now the Q is lowered to 0.614, and this response looks very nice. F3 is about 41 Hz, and F10 is 22 Hz.
Here is the resulting filter gain. It is very close to what an optimized asymmetric filter (or L-T filter) would be, but for me this is easy to manually set up and control.
j.
Good catch on the DSP type. Forgot all about that.
Something to keep in mind using a shelf. If your enclosure is a high Q alignment, you'll also need to suppress the bump above the knee. Not a big deal. Either method works fine.
Might also want to put a high pass on the bottom end. Say a 4th order high pass at 18hz. Especially if you use the LT technique. A lot of boost gets programmed in at the bottom and it's easy to clip the amp or exceed the excursion capes of the woofer if you crank the volume on synthetic bass music or a movie. Normal music doesn't really have any content down that low.
Something to keep in mind using a shelf. If your enclosure is a high Q alignment, you'll also need to suppress the bump above the knee. Not a big deal. Either method works fine.
Might also want to put a high pass on the bottom end. Say a 4th order high pass at 18hz. Especially if you use the LT technique. A lot of boost gets programmed in at the bottom and it's easy to clip the amp or exceed the excursion capes of the woofer if you crank the volume on synthetic bass music or a movie. Normal music doesn't really have any content down that low.
Thank you for all these. My Easter weekend will be busy! There is lots of rain in the forecast, so some indoor activity.
Something I do not understand. @Busdriver02 you have e multiple lines in the top graph and you have a DI curve. I have a single one and no DI.
Why such a deep cut at 256Hz? It seems to result in a good response but where in the original response you see that such a deep cut is needed?
Also: my woofers are capable of playing much higher that 300Hz. Is there any merit in using a higher crossover point? Say, 350 or 400?
Similarly, the midrange can go a bit lower (but not much). Any merit is crossing over lower?
Post #451 See the shape of the out of phase reverse nulls. The one on the right is smooth but the one on the left isn't as smooth. I suspect the deep notch was to make that better, although he may have also looked at the raw response, and saw a bit of a peak there. It's mostly to improve the way the mid, and woofer sum. More than one way to do that. Also he mentioned it as an experiment. When you take more measurements, there's a good chance that's not needed.
Crossing lower may be great at low SPL with some music. Power handling for the mid will be better when crossed higher. Every design has compromises. ( trade-offs ) Picking 400hz was a reasonable starting point. You could design a filter for 300hz, and compare the two with music to see what you like most.
Crossing lower may be great at low SPL with some music. Power handling for the mid will be better when crossed higher. Every design has compromises. ( trade-offs ) Picking 400hz was a reasonable starting point. You could design a filter for 300hz, and compare the two with music to see what you like most.
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temp25 has is. The summation in mid/woofer crossover was weird, so I flipped the polarity on the mid to take a look. I'm not convinced the phase weirdness isn't a product of measuring in room however, hence the experiment.
The crossover there is also set at 300hs in the filters, but you can see that it actually occurs at 400 in the simulation. I think that is a result of the notch we just talked about and the strong woofer response bump at 280hz. I'm not convinced the 280hz bump is real either, same problem with room reflections.
I don't know how to export a gated response out of REW, which is why I use 1/3 smoothing in VCAD but there still might be remnants of the limited measurement technique.
The crossover there is also set at 300hs in the filters, but you can see that it actually occurs at 400 in the simulation. I think that is a result of the notch we just talked about and the strong woofer response bump at 280hz. I'm not convinced the 280hz bump is real either, same problem with room reflections.
I don't know how to export a gated response out of REW, which is why I use 1/3 smoothing in VCAD but there still might be remnants of the limited measurement technique.
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