baggerbole, Vituixcad is well known. If you are downloading from the correct source then it is unlikely to have problems.
You might try asking here - https://www.diyaudio.com/community/threads/vituixcad.307910/
You might try asking here - https://www.diyaudio.com/community/threads/vituixcad.307910/
Hi Perry, I will play with it.
Until then, I went back to the old trusty EA15A in the series config, with the 1808 (https://www.diyaudio.com/community/threads/my-open-baffle-journey.394806/post-7959804) - the sound is gorgeous.
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I will have to ! Along with ARTA suite, REW, VituixCAD...
All of them are loaded and installed in my PC...
I even have a dedicated external soundcard...
I will have to take the time to return to this kind of softwares and learn their idiosycrasies, after leaving my obsolete LspLAB and SpectraLAB (thank you Windows) that I used for years...
Yes : I'm lazy and miss time to (re)do all this !
T
The following is my first 3-way build with an entirely series crossover.
Woofer: GRS 8SW-4 HE 8” subwoofer
Midrange: Dayton RS125-4 ohm 5” aluminum cone midrange
Tweeter: SB Acoustics SB19ST-C000-4 with additional 3D printed waveguide (kudos to @wolf_teeth for the mid and tweeter, they were door prizes at his InDIYana event which was fun).
Photo of system:
Crossover simulation in VituixCad:
Discussion:
The impedance peak of a midrange like this is hard to deal with, using a standard parallel crossover. I feel getting this level of performance from a 3 way crossover with only 12 passive components is very attractive.
The impedance curve is smooth, and the drive signal curves from the filter outputs on the right middle panel are very well behaved.
You'll notice a sharp dip at 180Hz. That is very angle and boundary dependent. You see hints of it in the real world measurements but overall it seems to be a non-issue. If you reverse the polarity of one driver you get a huge dip at that frequency.
On the midrange I used a notch filter instead of a standard high pass filter. That reduced phase shift, and got the vertical lobing exactly where I wanted it.
The series crossover also managed to give me “shelf” characteristics for both midrange and tweeter that were exactly what I needed, without extra components.
Measurements:
ON AXIS - The 58Hz peak is a room mode.
Off axis Horizontal performance is outstanding, there is no visible “seam” at the crossover frequency, it exhibits quasi-Constant Directivity behavior above 200Hz.
Polar Heat Map
I’m very happy with the polar map view as well. I generated this plot using ChatGPT from the data in the previous off axis frequency response graph.
One of the reasons this system achieves Constant Directivity behavior below 1000Hz is the diffraction characteristic of the 8" wide baffle. I discuss this in another thread: https://www.diyaudio.com/community/threads/constant-directivity-without-horns-or-waveguides.422090/
Series crossovers are definitely more tricky to juggle but if you can get the planets to line up you can kill a lot of birds with not many stones.
Woofer: GRS 8SW-4 HE 8” subwoofer
Midrange: Dayton RS125-4 ohm 5” aluminum cone midrange
Tweeter: SB Acoustics SB19ST-C000-4 with additional 3D printed waveguide (kudos to @wolf_teeth for the mid and tweeter, they were door prizes at his InDIYana event which was fun).
Photo of system:
Crossover simulation in VituixCad:
Discussion:
The impedance peak of a midrange like this is hard to deal with, using a standard parallel crossover. I feel getting this level of performance from a 3 way crossover with only 12 passive components is very attractive.
The impedance curve is smooth, and the drive signal curves from the filter outputs on the right middle panel are very well behaved.
You'll notice a sharp dip at 180Hz. That is very angle and boundary dependent. You see hints of it in the real world measurements but overall it seems to be a non-issue. If you reverse the polarity of one driver you get a huge dip at that frequency.
On the midrange I used a notch filter instead of a standard high pass filter. That reduced phase shift, and got the vertical lobing exactly where I wanted it.
The series crossover also managed to give me “shelf” characteristics for both midrange and tweeter that were exactly what I needed, without extra components.
Measurements:
ON AXIS - The 58Hz peak is a room mode.
Off axis Horizontal performance is outstanding, there is no visible “seam” at the crossover frequency, it exhibits quasi-Constant Directivity behavior above 200Hz.
Polar Heat Map
I’m very happy with the polar map view as well. I generated this plot using ChatGPT from the data in the previous off axis frequency response graph.
One of the reasons this system achieves Constant Directivity behavior below 1000Hz is the diffraction characteristic of the 8" wide baffle. I discuss this in another thread: https://www.diyaudio.com/community/threads/constant-directivity-without-horns-or-waveguides.422090/
Series crossovers are definitely more tricky to juggle but if you can get the planets to line up you can kill a lot of birds with not many stones.
Series crossover for subwoofer / satellite, Part 2
(Or, The Real Reason Subs Are So Hard to Integrate)
Everybody knows adding a sub is a lot easier on paper than in real life. Most conversations about this have to do with room boundaries, crossover points and whether the sub is too “slow” for the satellites (which could also be planars or ribbons).
Fair enough... but maybe the real reason, which nobody seems to talk about much, is how ugly the impedance interactions are between a satellite and a passive crossover. Especially if the satellite is bass reflex.
I’ll start with a passive example but at the end I’ll get into passive / active hybrids.
I’m installing speakers on my porch. What I’ve got to work with is a Dayton PS95 3.5” full range driver in a 1 liter box with a 4” passive radiator and Audax TW60A super tweeter mounted on the back.
This most important thing you can know about the PS95 reflex is its impedance curve:
The saddle between the two peaks tells you the reflex tuning frequency is 90Hz. This means the system can comfortably handle power and drive the passive radiator from about 80Hz to 120Hz, but below 80Hz, the driver is unloaded. Excursion runs rapidly out of control. At the lower resonance of 65Hz, the PS95 full range is very vulnerable to overload.
So let’s run through our crossover options.
First a 6dB simple high pass filter:
As you can see the drive voltage is +1 dB (not even -1 dB) at 60Hz. NO GOOD. The crossover offers zero protection above 50Hz, and at 60Hz all you’re going to hear from the PS95 is distortion. Flapping in the breeze. It's not much better than no crossover at all.
You can tweak the 200uF cap down to 100 or even 50uF but all you manage to do is create a suck-out at 200Hz which we do not want.
So let’s try a 12dB standard filter:
This is TERRIBLE. It does protect the satellites from low bass, but in every other respect it's worse. We can tweak the values but pretty much no matter what you do, you're going to get a peak at 160Hz because of the impedance of the PS95 reflex. Not only that, the input impedance dips down to 1 ohm!
If you're using passive crossovers, I suspect this is the biggest culprit in subs and satellites not blending.
So let’s try a "series 6dB/octave" filter. Again my subs are Tang Band 5” W5-1138 in a ported box tuned to 38Hz. These Vituixcad simulations are based on actual impedance measurements.
This is excellent. It does exactly what I want and the satellites drop like a rock below 70Hz. The low pass on the sub is roughly 6dB/octave above 120Hz, and the high pass on the satellites is more like a 2nd order shelf filter, as discussed at the top of this thread with the Bitches Brews. Signal to PS95 Satellites is -15dB at 60Hz which is great.
Now here comes the twist. Dayton sells a 3 channel subwoofer satellite Class D amp with a variable active 12dB crossover on the subwoofer (that’s great) and no high pass function on the satellites (not great for my application).
This is very attractive for the subwoofer department, but our options for high-passing the satellites are still lousy.
But let's try a series crossover just for the high pass. Except instead of putting the sub in the circuit, I swap in a 6.2 ohm resistor:
At 60Hz the high pass filter is -8dB.
I can’t say I’ve ever seen this circuit used like this. It gives me something in between an actual 6dB to 12dB per octave slope without any of the usual erratic behavior.
So now we've got a couple of decent choices: A completely passive 2-channel system where the satellites are -15dB @60Hz, or a hybrid 3 channel system where the satellites are -8dB at 60Hz, plus we have the knobs on the DTA2.1 amps where you can change both the subwoofer level and the crossover frequency.
I may test both.
The punch line is that is the standard off the shelf "parallel" crossover, almost universal in passive crossovers, gives me a nasty 15dB peak (as seen above, 3rd image from the top):
But the following high pass circuit was derived from a series crossover, with a resistor swapped in for a driver:
It has no erratic behavior. Vastly superior to the conventional circuit.
(Or, The Real Reason Subs Are So Hard to Integrate)
Everybody knows adding a sub is a lot easier on paper than in real life. Most conversations about this have to do with room boundaries, crossover points and whether the sub is too “slow” for the satellites (which could also be planars or ribbons).
Fair enough... but maybe the real reason, which nobody seems to talk about much, is how ugly the impedance interactions are between a satellite and a passive crossover. Especially if the satellite is bass reflex.
I’ll start with a passive example but at the end I’ll get into passive / active hybrids.
I’m installing speakers on my porch. What I’ve got to work with is a Dayton PS95 3.5” full range driver in a 1 liter box with a 4” passive radiator and Audax TW60A super tweeter mounted on the back.
This most important thing you can know about the PS95 reflex is its impedance curve:
The saddle between the two peaks tells you the reflex tuning frequency is 90Hz. This means the system can comfortably handle power and drive the passive radiator from about 80Hz to 120Hz, but below 80Hz, the driver is unloaded. Excursion runs rapidly out of control. At the lower resonance of 65Hz, the PS95 full range is very vulnerable to overload.
So let’s run through our crossover options.
First a 6dB simple high pass filter:
As you can see the drive voltage is +1 dB (not even -1 dB) at 60Hz. NO GOOD. The crossover offers zero protection above 50Hz, and at 60Hz all you’re going to hear from the PS95 is distortion. Flapping in the breeze. It's not much better than no crossover at all.
You can tweak the 200uF cap down to 100 or even 50uF but all you manage to do is create a suck-out at 200Hz which we do not want.
So let’s try a 12dB standard filter:
This is TERRIBLE. It does protect the satellites from low bass, but in every other respect it's worse. We can tweak the values but pretty much no matter what you do, you're going to get a peak at 160Hz because of the impedance of the PS95 reflex. Not only that, the input impedance dips down to 1 ohm!
If you're using passive crossovers, I suspect this is the biggest culprit in subs and satellites not blending.
So let’s try a "series 6dB/octave" filter. Again my subs are Tang Band 5” W5-1138 in a ported box tuned to 38Hz. These Vituixcad simulations are based on actual impedance measurements.
This is excellent. It does exactly what I want and the satellites drop like a rock below 70Hz. The low pass on the sub is roughly 6dB/octave above 120Hz, and the high pass on the satellites is more like a 2nd order shelf filter, as discussed at the top of this thread with the Bitches Brews. Signal to PS95 Satellites is -15dB at 60Hz which is great.
Now here comes the twist. Dayton sells a 3 channel subwoofer satellite Class D amp with a variable active 12dB crossover on the subwoofer (that’s great) and no high pass function on the satellites (not great for my application).
This is very attractive for the subwoofer department, but our options for high-passing the satellites are still lousy.
But let's try a series crossover just for the high pass. Except instead of putting the sub in the circuit, I swap in a 6.2 ohm resistor:
At 60Hz the high pass filter is -8dB.
I can’t say I’ve ever seen this circuit used like this. It gives me something in between an actual 6dB to 12dB per octave slope without any of the usual erratic behavior.
So now we've got a couple of decent choices: A completely passive 2-channel system where the satellites are -15dB @60Hz, or a hybrid 3 channel system where the satellites are -8dB at 60Hz, plus we have the knobs on the DTA2.1 amps where you can change both the subwoofer level and the crossover frequency.
I may test both.
The punch line is that is the standard off the shelf "parallel" crossover, almost universal in passive crossovers, gives me a nasty 15dB peak (as seen above, 3rd image from the top):
But the following high pass circuit was derived from a series crossover, with a resistor swapped in for a driver:
It has no erratic behavior. Vastly superior to the conventional circuit.
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Here is the same circuit, re-drawn in a more familiar "parallel crossover" format:
The 6.2 ohm resistor across the high pass capacitor is counterintuitive, but it dampes the resonance that would otherwise peak at 160Hz.
Raising the value of the resistor increases the peak and reduces LF input; reducing the value has the opposite effect.
The 6.2 ohm resistor across the high pass capacitor is counterintuitive, but it dampes the resonance that would otherwise peak at 160Hz.
Raising the value of the resistor increases the peak and reduces LF input; reducing the value has the opposite effect.