Hello,
Modeling 2-way boxes, vented midwoofer + tweeter. Probably it will be BR, but in the past had positive experience with building folded transmission lines for fullranges, so any type of TL is an option.
This is my first multiway project, and the driver selection and matching process kinda scares me a little. With your help would like to get to chose from 4 different woofers.
Hard requirements:
-Tweeter will be Vifa XT25SC90-04
-Woofer choice is limited to these 4
6" SB16PFCR25-4
6" SB16PFCR25-8
5" SB13PFCR25-4
5" SB13PFCR25-8
-Passive crossover. Will use electronic only to sim.
-Best overall experience: good match between those drivers, nice sound for various music listening and so on. Just looking for best package for the amount of money spent.
-Will print part or all of the front baffle with some shallow waveguide for tweeter, to match Z depth/time alignment of drivers, so the vertical distance c-c between drivers will be around the full diameter of the woofer.
-Baffle will have lots of round overs on the edges, as it will be partially or fully printed, as narrow as possible, just enough width for the woofer.
Nice to have:
-Crossover range in the most unobtrusive region. 3Khz+ would be perfect.
-Crossover with a reasonable amount of parts. 1st or 2nd order would be perfect, but not mandatory.
That is pretty much all.
The furniture or CAD sketching part is a joy for me, so no problems there. 3D modeling for printing also is not a problem at all. Have exactly 0 experience in designing crossovers, but started to play with XSim and VirtuixCAD, willing to learn.
There are many positive reviews of SB16PFC25 and SB13PFC25, those rounded corners square shaped, T/S is the same but the SPL graphs are a bit different. I assume, that they are exactly the same drivers, but that does not make the selection easier to me: both have generally positive reviews, there are reviews with the SB13 with exactly the same tweeter and there are reviews of the bigger SB16 with the similar Vifas. I am tempted to choose 6" because "bigger is better" but not so sure if I can cross it high enough for the tweeter to play nice. Speaker will powered by affordable Class D amps, 3116 and likes.
Also: 4 or 8 Ohm?
Any advice on the topic is very appreciated, thank you in advance.
Modeling 2-way boxes, vented midwoofer + tweeter. Probably it will be BR, but in the past had positive experience with building folded transmission lines for fullranges, so any type of TL is an option.
This is my first multiway project, and the driver selection and matching process kinda scares me a little. With your help would like to get to chose from 4 different woofers.
Hard requirements:
-Tweeter will be Vifa XT25SC90-04
-Woofer choice is limited to these 4
6" SB16PFCR25-4
6" SB16PFCR25-8
5" SB13PFCR25-4
5" SB13PFCR25-8
-Passive crossover. Will use electronic only to sim.
-Best overall experience: good match between those drivers, nice sound for various music listening and so on. Just looking for best package for the amount of money spent.
-Will print part or all of the front baffle with some shallow waveguide for tweeter, to match Z depth/time alignment of drivers, so the vertical distance c-c between drivers will be around the full diameter of the woofer.
-Baffle will have lots of round overs on the edges, as it will be partially or fully printed, as narrow as possible, just enough width for the woofer.
Nice to have:
-Crossover range in the most unobtrusive region. 3Khz+ would be perfect.
-Crossover with a reasonable amount of parts. 1st or 2nd order would be perfect, but not mandatory.
That is pretty much all.
The furniture or CAD sketching part is a joy for me, so no problems there. 3D modeling for printing also is not a problem at all. Have exactly 0 experience in designing crossovers, but started to play with XSim and VirtuixCAD, willing to learn.
There are many positive reviews of SB16PFC25 and SB13PFC25, those rounded corners square shaped, T/S is the same but the SPL graphs are a bit different. I assume, that they are exactly the same drivers, but that does not make the selection easier to me: both have generally positive reviews, there are reviews with the SB13 with exactly the same tweeter and there are reviews of the bigger SB16 with the similar Vifas. I am tempted to choose 6" because "bigger is better" but not so sure if I can cross it high enough for the tweeter to play nice. Speaker will powered by affordable Class D amps, 3116 and likes.
Also: 4 or 8 Ohm?
Any advice on the topic is very appreciated, thank you in advance.
I designed a 3-way floorstander with the sb13pfc-8 for a friend and he is very happy with it. In a 2-way I would use the sb16 crossed at 2200-2500Hz
If your amp has no problems with low impedance there are no costraints to use the 4R versions, just choose the one that fits better for the enclosure you have in mind.
Give a look here for a 2-way with the 5" midwoofer
https://xmachina-ai.blogspot.com/2023/02/version-of-small-full-range-and.html
or here for the drivers test (if you register you can download the FR/ZR measurements)
http://www.dibirama.altervista.org/le-prove/mid-woofer.html
If your amp has no problems with low impedance there are no costraints to use the 4R versions, just choose the one that fits better for the enclosure you have in mind.
Give a look here for a 2-way with the 5" midwoofer
https://xmachina-ai.blogspot.com/2023/02/version-of-small-full-range-and.html
or here for the drivers test (if you register you can download the FR/ZR measurements)
http://www.dibirama.altervista.org/le-prove/mid-woofer.html
SB16PFCR-8 sounds great and reaches low in the right cabinet. However, there is some cone breakup so not sure it will reach to 3khz, especially with shallow slopes.
I built a two way this fall with the XT25SC40-4 (the one without a faceplate) and the Visaton WG148R waveguide. Crossed around 2.3khz, probably LR4 if I remember correctly, 8 crossover parts.
I built a two way this fall with the XT25SC40-4 (the one without a faceplate) and the Visaton WG148R waveguide. Crossed around 2.3khz, probably LR4 if I remember correctly, 8 crossover parts.
Attachments
Nice looking project! LR4 on tweeter of woofer? 8 parts total on the high and low pass? I am very interested.
The best of both worlds is to have SB16 bass with SB13 crossover point, but I have to choose. I prefer sound of high crossed tweeters.
Have you tested with digital XO before building? From the charts off axis response separates from around 1600Hz, did you made slope from that point?
I will attach it from the front and my waveguide will be similar, but to community this knowledge is interesting too
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Depends how you like your bass, and the listening situation, The 5" drivers are great for desktop use, but in a room I'd go for 6". The 8 ohm version is the best match in sensitivity for the tweeter, but the 4 ohm will give you some extra dB if you intend to deal with baffle step compensation in the xover.
(If it was me, I'd go for 2x 6" in a 2.5 way design)
(If it was me, I'd go for 2x 6" in a 2.5 way design)
I read about your Mechano projects before posting there 🙂 Initially I thought about SB13, but your project is the exact reason why I started to doubt my choice.
Couple of questions:
1. 13 (THIRTEEN) parts on crossover... Are those drivers THAT troublesome???
2. Why u chose 4 Ohm woofer?
It has to be something universal, cheerful and fun. Speakers probably will be used in totally not perfect conditions, in a bad acoustically room, with random listening position, with people moving around and so on. Overall I do not want to pick blindly "more bigger = more better" drivers.
I can and probably will make baffle almost any reasonable shape and size as I want: baffle width fits into dimensions of the 3D printer I have access to. Also they will be placed on the wall shelf . Does it mean I need baffle step compensation still? It is still a bit gray zone for me. I am leaning towards SB16 8 Ohms because of sensitivity
There's a video project on YouTube called the "Life S5" which used the SB13pfc-4 and that Vifa tweeter,
The speaker was designed as a monitor so may not suit your purposes but the design and test process is most interesting.
The designer won 'best iron driver' at a Parts Express event with a different speaker.
I used the SB16pfc-8 in Michael Chua's "Lark SM" and it's a great sounding mid for the price, although the frame shape was a pain. Luckily for you, these have been replaced by round frames. The 'sound of round' is supposed to be the same as the previous version.
Geoff
The speaker was designed as a monitor so may not suit your purposes but the design and test process is most interesting.
The designer won 'best iron driver' at a Parts Express event with a different speaker.
I used the SB16pfc-8 in Michael Chua's "Lark SM" and it's a great sounding mid for the price, although the frame shape was a pain. Luckily for you, these have been replaced by round frames. The 'sound of round' is supposed to be the same as the previous version.
Geoff
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That small xt25 is better crossed about 3khz. So better match is sb13pfcr
Mechano project is not mine, it was designed by @XMechanik. If you search here on the forum there is a dedicated thread in which the project has been illustrated. I used the 8 Ohm version in my 3-way and I used a 2nd order on LP and HP and a couple of resistance for attenuation and damping.
Anyway, I think he used the 4 Ohm version in order to compensate the low sensitivity of a 5" driver.
The Visaton waveguide takes M4 bolts, so I used the disc left over from the baffle cutout and made an adapter that sandwiched the tweeter to the waveguide. But this worked because the XT25 without a faceplate is so small. If I used the larger XT25's or a something like the Dayton RST28 then the tweeter would have covered up the bolt holes and I would have had to make a more complicated adapter.
Here are are the measurements of the woofer, I think the baffle is 8-1/2" wide with a 3/4" roundover.
Note the cone breakup past 4Khz. One way to get rid of this is to slice the cone like THIS. But I don't think that is an appealing option for most people. But this is why I don't think a 3Khz crossover is feasible with the SB16.
Here is the VituixCAD 6-pack. 8 components total. The crossover is actually LR4 at 2300Hz. That is lower than ideal for the tweeter, but I'm not listening to these loud.
Note the tiny 0.22uF capacitor in parallel with the inductor on the woofer. That is pushing the breakup down about 4 to 5 db. The green line below is without it. I didn't listen with and without it, I figured it is a cheap component and I'd just use it.
I have these from ebay, "Vifa" XT25A China made. I tried them as a backfire tweeter and they play great, very clean. The price is a real trifle (around $30 a pair). This version is 8ohm, I think there are also 6ohm and 4ohm versions. I think they would be good for a 3k5 cut - 2nd or 3rd order in combination with some cheap 4" to 5" mid bass or mid range drivers. I took more pieces to play with. 😏
Attachments
Here are are the measurements of the woofer, I think the baffle is 8-1/2" wide with a 3/4" roundover.
Note the cone breakup past 4Khz. One way to get rid of this is to slice the cone like THIS. But I don't think that is an appealing option for most people. But this is why I don't think a 3Khz crossover is feasible with the SB16.
Here is the VituixCAD 6-pack. 8 components total. The crossover is actually LR4 at 2300Hz. That is lower than ideal for the tweeter, but I'm not listening to these loud.
Yes, cone breakup looks like 5-6dB spikes, that is not nice.
2300Hz is your xrossover point, and I am kinda guessing that 5" version could squeeze more of usable woofer range, so I could make similar LR4 at ~2500Hz or even into 2900-3000Hz? All three are more or less still in the telephone range, so which crossover point of those will be most tolerable:
Option 1: 2300Hz with 6 incher - shameless copy of yours
Option 2: ~2500Hz with 5 incher - kinda free from cone breakup artefacts
Option 3: 2800-3000Hz with 5 incher - with some woofer cone artefacts, but totally safe for tweeter
Still learning how to read crossover graphs. Couple of questions:
1, Looks like at crossover point it is exactly -6dB, so does this mean that at the exact crossover point drivers are in phase? Phase graph shows just simple downward slope at this point, so don't know how to interpret this. And phase rotation is at ~1850Hz, which is ~-2dB from woofer and ~-11dB from tweeter. Don't know how to sum those numbers but is that range from 1850Hz of phase rotation until crossover point and lets say up to ~2600Hz somehow troublesome? Does it sound OK (-ish)?
2. Those bumps at ~650Hz and~4500Hz are around 2dB which is not much but can be heard I think. Can they be heard in the normal background/foreground music listening?
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Actually, this is pretty good for a 6-1/2" driver. An aluminum cone would typically be much worse. 6-1/2" drivers are just not usually made to crossover at 3 to 4khz.
You can't really decide the crossover point ahead of time. Your main constraint will be matching directivity of the woofer and the tweeter. A 5" woofer will allow you to crossover higher. A 6-1/2 driver will need to crossover lower. With a typical 6-1/2" driver I would start with the assumption that I will need to crossover between 2-2.5khz and pick a tweeter that can do that.
You already have a tweeter which normally shouldn't be crossed over below 2.5khz. That would suggest using a 5" driver. BUT...if you are putting it in a waveguide that will boost the low end of the tweeter and allow you to go a little lower than usual. So the question, becomes, do you stretch the useable range of the tweeter to get the extra bass from the 6-1/2" driver. You did not mention a subwoofer; If you have a subwoofer I'd go with the 5", as it will make things easier with your tweeter. But I can tell you, that with the 6-1/2" in my 12 ft x 12 ft office I do not need a subwoofer.
I start out with a simulation with good phase matching and then focus on on-axis and directivity issues. I'll come back and check phase at the end, but it's not something I worry too much about. What you want is to have the drivers phase to be close around the crossover point. You can see the green line (woofer phase) and the red line (tweeter phase) are almost right on top of each other from 1khz to 4khz which is pretty good. These speakers sound quite good, and they sound great for the cost.
That bump at 650hz is only 1.25db for a half-octave and is not going to be noticeable.
The bump at 4.5khz is a bit more than 2db but is only a half-octave, above 3.5khz, so I didn't worry about it. I could have added 3 more components and notched it out, but that didn't make much sense for what was meant to be a budget build. I might have added it if it was between 1khz and 3khz. Also, you can't see it with the polar plot, but if I had used a line graph you'd see they are pretty flat at 10 degrees off axis. So I just have them pointed straight ahead rather than toe-ing them in toward me.
That 2mH 0.31Ohm coil is ~20AWG? Di you used air core or iron core? Air core of such small resistance looks around half of SB woofer cost...