When I make a 3-way, I do a lot of things. I like Sims, but that's just a tool, not an all or nothing system.
Your tweeter does not need to be measured closer than 1m.
Your tweeter to mid x-over is easy with current measurements. It's the mid to woofer that is in need of additional measuring.
The woofer is predictable to 200hz, maybe to 400hz, and although it's nice to have all these different measurements, they could just confuse the issue. Not saying don't do them.
Mostly you want to get things smooth between 100hz, and 1k. Doing so may be relatively easy. Measuring, and predicting may be harder. With active, it should be easy. I'm doing passive only these days, and that is much harder. Multiple woofers make it difficult as well.
A close mic on the mid is a great idea.
A close mic on the woofer as well.
I would also take a measurement of the woofers at 1m between the woofer center lines. Not on the tweeter center line.
Your tweeter does not need to be measured closer than 1m.
Your tweeter to mid x-over is easy with current measurements. It's the mid to woofer that is in need of additional measuring.
The woofer is predictable to 200hz, maybe to 400hz, and although it's nice to have all these different measurements, they could just confuse the issue. Not saying don't do them.
Mostly you want to get things smooth between 100hz, and 1k. Doing so may be relatively easy. Measuring, and predicting may be harder. With active, it should be easy. I'm doing passive only these days, and that is much harder. Multiple woofers make it difficult as well.
A close mic on the mid is a great idea.
A close mic on the woofer as well.
I would also take a measurement of the woofers at 1m between the woofer center lines. Not on the tweeter center line.
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Maybe, but I will still learn a lot, so I will go through it.
I think oyu are right re the mid/tweeter. They both sound near perfect already, so not much to change there apart from general smoothing with EQ. I do not see and I think no one else flagged any problems related to it.
I think oyu are right re the mid/tweeter. They both sound near perfect already, so not much to change there apart from general smoothing with EQ. I do not see and I think no one else flagged any problems related to it.
No need for tweeter nearfield measurements, the useful range is still perfectly fine when farfield, gated.
for mic safety?
You could start with 25 mm and once you are comfortable with levels and excursion you can reduce it to 5 mm. You need to keep level low anyways in order not to overload the mic.
OK, @stv beat me to it
1. you have to apply a low level because the mic is so close to the driver that it is likely it will distort.
2. If you do not cover the 2nd woofer the mid fr (of the wf) will be captured by the mic.
1. you have to apply a low level because the mic is so close to the driver that it is likely it will distort.
2. If you do not cover the 2nd woofer the mid fr (of the wf) will be captured by the mic.
Noted re levels.
I think I am missing something.
--- the mid fr (of the wf) will be captured by the mic. ---
the mic will capture all frequencies played by the 1st (measured) woofer. The mic will also capture any other signals that reach it. Are you saying the mid frequencies (from the 2nd woofer) will reach the fist woofer if it is not covered? why lows and highs would not reach the mic or why they are not a concern?
I think I am missing something.
--- the mid fr (of the wf) will be captured by the mic. ---
the mic will capture all frequencies played by the 1st (measured) woofer. The mic will also capture any other signals that reach it. Are you saying the mid frequencies (from the 2nd woofer) will reach the fist woofer if it is not covered? why lows and highs would not reach the mic or why they are not a concern?
The mids from the second woofer will arrive at the mic delayed by the distance between the woofers.
So the mid frequencies will be affected. Mids being above maybe 300hz. Below that, I think they should be accurate.
I don't think it's a big deal, but it all depends on how you interpret your measurements, and what you use them for. The close mic will be useful to sim the boost below 100hz.
Measuring at 1m as I suggested will show the effect of the baffle, and how the woofer response is up higher. If instead, you measure on the tweeter axis, there will be some mid frequencies that cancel due to the path difference between the mic, and each woofer.
So the mid frequencies will be affected. Mids being above maybe 300hz. Below that, I think they should be accurate.
I don't think it's a big deal, but it all depends on how you interpret your measurements, and what you use them for. The close mic will be useful to sim the boost below 100hz.
Measuring at 1m as I suggested will show the effect of the baffle, and how the woofer response is up higher. If instead, you measure on the tweeter axis, there will be some mid frequencies that cancel due to the path difference between the mic, and each woofer.
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You don't care about highs from the near field. They won't be used. They will be cut off, and the lows spliced to other measurements.
The wavelengths of low frequencies are longer. The short distance between drivers, and the delay will not affect the lows.
The wavelengths of low frequencies are longer. The short distance between drivers, and the delay will not affect the lows.
Please study the instructions from kimmosaunisto.net - and follow them. Stop listening to mixed info.
also https://www.youtube.com/@kimmosto
Initial measurements must be done with only one driver/way playing, and same gain setting in the amplifier. Twin drivers is an exception, see instructions.
also https://www.youtube.com/@kimmosto
Initial measurements must be done with only one driver/way playing, and same gain setting in the amplifier. Twin drivers is an exception, see instructions.
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I'm not trying to talk you out of following other suggestions, step by step. It's good that you want to learn a procedure.
What I'm suggesting is that there are options. I can't tell you step by step everything. Things change as you proceed. . You want to know why some things are done as they are. I try to answer some of those questions.
Taking the measurements I suggested does not change taking the measurements others suggested. They are simply additional measurements. Maybe you won't use them, but if posted here, I might. I like playing along, but have no interest in kimmosaunistos method. It may be perfect. Don't care, and don't need it, but you might like it. Wouldn't it be cool if my suggested x-over was virtually identical to the one you come up with, but using totally different method to get there?
Did you commit to using a particular method of measuring, and designing your x-over? I might have missed that.
What I'm suggesting is that there are options. I can't tell you step by step everything. Things change as you proceed. . You want to know why some things are done as they are. I try to answer some of those questions.
Taking the measurements I suggested does not change taking the measurements others suggested. They are simply additional measurements. Maybe you won't use them, but if posted here, I might. I like playing along, but have no interest in kimmosaunistos method. It may be perfect. Don't care, and don't need it, but you might like it. Wouldn't it be cool if my suggested x-over was virtually identical to the one you come up with, but using totally different method to get there?
Did you commit to using a particular method of measuring, and designing your x-over? I might have missed that.
Me? I am too dumb an lazy to learn any simulation except The Edge. I have set up four multiway dsp active speakers and the stories can be found at diyaudio. com
My post was for the OP. When I said you, I meant the OP. I think I started the post before you posted, but read your post when a new post alert appeared.
Why would you tell him to stop listening to me, and others?
Why would you tell him to stop listening to me, and others?
You could also take an additional measurements about 12" from the baffle, and centered directly between the woofers. That would tell you about the same as the closer mic measurement.
Did I mention turning the speaker horizontal? You could also turn it upside down, and on a box to get the woofers higher.
Did I mention turning the speaker horizontal? You could also turn it upside down, and on a box to get the woofers higher.
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I consider all advice and try to systemize it myself and then apply as I go. There may be multiple ways of arriving to a good solution. Most importantly I want to understand things, not just follow a fool-proof guide (not that there is anything wrong with these either).
re crossover design, I think what I already have for the MF/HF is already very good. I just need to improve the LF/MF XO, BSC and the LF equalisation. In terms of measurements I have not yet even achieved a good baseline set (which I understand as a set of good off axis and a nearfield set).
I then plan to learn import and merge in VCAD. Then re-read all the XO and LF EQ advice given here and try a few XO/EQ ariants - in VCAD sim and then by listening, and report back. this weekend will be for the nearfields.
Obviously OP wants to learn to use VituixCAD. It is versatile, but the author's instructions should be priority. Suggesting many alternative methods is confusing IMO
There are many spesific threads of "how to" vcad here and at other forums and YT
And then setting up Hypex FA253...
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I find using Hypex FA the easiest part of this set up. Largely because of the very good guide on this forum by @DannerD3H
What you could do..... In addition to other measurements ...Not trying to change the plan of attack....
Ok, several of us have simmed the low end boost. I assume that programming one or all of them into action is easy. Since SPL varies with cone movement, and a close mic will show the roll-off, why not go ahead and program the bass boost into the unit ahead of time, and make a near field sweep. If it's a straight line from 200hz down to 40hz, you pretty much know what you got. If not, a quick adjustment will put you there. Then turn off the boost, sweep again, and let software predict what is needed. Then add it, and measure again, to verify it works. Either way works. Which is easier? I really don't see it as confusing. It's bass boost. You will decide how low to extend it. The deeper you go, the more excursion. I think for myself, I would shoot for a 40hz f3. , and possibly lower. What would be cool is if the setup has a limiter built in. Then you never have to worry about getting too loud.
Here's my estimate for boosting the low end. It's just an estimate. Looks about right on the graph to me.
Note.... Never used this LT function before. No harm in making adjustments. I went with what the transfer function looked like.
Attachments
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Sure. Say the tweeter has a natural mechanical low frequency roll off at 1350 Hz, it is effectively a 2nd order high pass filter with some arbitrary Q set by the driver properties. If you just cascade a 4th order LR filter at the 2000 Hz desired crossover frequency, you end up with a sort of 6th order filter response and resulting phase shift that won't play nicely with the low pass filter on the midrange or woofer. Starting with the Linkwitz transform (asymmetric 2nd order shelf filter) the 1500 Hz and arbitrary Q response can be canceled and replaced with the desired 2000 Hz, Q = .707 response desired to form half of the LR 4th order filter. I have tried to measure the Q and low frequency resonance using DATS or other impedance sweeps, but a simple near field acoustic measurement and just eyeballing the Q value works well.
I made a copy of the miniDSP spreadsheet in Google Sheets to calculate the coefficients of the Linkwitz transform. The example below shows how the natural response of a tweeter with a 1350 Hz Q = 1.2 ( Dark Blue ) can be shifted with the filter ( Light Blue ) to produce a 2000 Hz 0.7 Q high pass response ( Medium Blue? ). I'm a bit color blind.
I'm not sure but the Hypex software may have the 2nd order asymmetric shelf filter in the menu. The miniDSP requires typing in the filter coefficients, which isn't great. The link below the figure takes you to the spreadsheet.
https://docs.google.com/spreadsheets/d/1SxDCrRJwczpLxShdq1TUdDULetdWTp43npEBMxRZWfw/edit?usp=sharing
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