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Small 2-way speakers with linear on-axis and power response characteristics (Scan Speak and SB Acoustics drivers). H&V off-axis measurements included

@XMechanik, I have a couple of questions regarding your great crossover designer tool:
1- In your first post there is a screenshot of the tool with the target estimated in room response and the result overlayed. In your youtube and pdf manual I don't see an option for that? Is that image manually created?
2 - I don't fully understand the 'delay' setting in the 'ways' node. I'm trying to design my own speaker now and have measured the drivers according the manual kimmo wrote. So every driver is measured on it's own Y-axis (mic was moved to vertical center of each driver for the polar measurements). So the delay of the measurements is the same for all I gues?
3 - Is there a way to export a design to vituixcad?
 
1- In your first post there is a screenshot of the tool with the target estimated in room response and the result overlayed. In your youtube and pdf manual I don't see an option for that? Is that image manually created?
The pdf and YT videos were created for the early versions of XMachina software and they were never updated. Later releases had short description for the new features. You can find an index of them here link.
2 - I don't fully understand the 'delay' setting in the 'ways' node. I'm trying to design my own speaker now and have measured the drivers according the manual kimmo wrote. So every driver is measured on it's own Y-axis (mic was moved to vertical center of each driver for the polar measurements). So the delay of the measurements is the same for all I gues?
The delay parameter is for on-axis calculations only. The XYZ parameters in XMachina are not used for on-axis calculation. Taking as an example the most common case when "on-axis" means actually "on-tweeter-axis" the delay parameter is to apply phase correction for the woofer, as the distance to the woofer acoustic center is a bit longer. Note that the delay parameter is not used for Power Response characteristic calculation (only the XYZ parameters are used here).
3 - Is there a way to export a design to vituixcad?
Basically no, but since there is usually a dozen of components in a crossover it's not a big problem.
 
The pdf and YT videos were created for the early versions of XMachina software and they were never updated. Later releases had short description for the new features. You can find an index of them here link.

The delay parameter is for on-axis calculations only. The XYZ parameters in XMachina are not used for on-axis calculation. Taking as an example the most common case when "on-axis" means actually "on-tweeter-axis" the delay parameter is to apply phase correction for the woofer, as the distance to the woofer acoustic center is a bit longer. Note that the delay parameter is not used for Power Response characteristic calculation (only the XYZ parameters are used here).

Basically no, but since there is usually a dozen of components in a crossover it's not a big problem.
Thanks for the reply. Your mechano23 speaker really triggered me to get into diy speakers.
I'll read up tomorrow. I'm trying to make a 2way sealed speaker that maintains a constant directivity for the upper 2 octaves or so.
 
I finally finished my speakers. Thanks XMechanik for the design and Wineds for the PCB. Also others for the helpful comments. It was Amirm’s last paragraph that inspired me to make them. Unfortunately, I do not have any way to measure their performance but they sound great and I could listen to them all day.
 

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A few observations in case someone has comments or suggestions. While handling (inserting) the tweeter, I managed to break one of the terminal posts. I soldered it back on as best as I could and that seemed to work. Not sure if that had any impact. I am using a Fosi BT20A Pro amp with a whopping 48V/10A brick for power. Yet I need to crank up the volume to maximum to drive the speakers. In other words, they were not very loud at lower volumes. Using a free dB app, I got about 65 to 75 dB. Not sure if this is expected. Overall, as I mentioned earlier, they sound great and I am very happy I made them.
 
I need to crank up the volume to maximum to drive the speakers. In other words, they were not very loud at lower volumes. Using a free dB app, I got about 65 to 75 dB. Not sure if this is expected.
There seems to be some problem with your setup. I once measured the speakers at 96dB/1m spl level and I'm pretty sure the volume knob was not exceeding 11 o'clock position. My amp is a simple Denon 80W AB-class and your Fosi BT20A Pro is a 300W D-class amp, right?. The power seems to be enough to rip the cone out of the speaker basket. The first thing to check would be to see if the source level is matched to the amplifier sensitivity.
Either way, I'm glad you like the sound :).
 
There seems to be some problem with your setup. I once measured the speakers at 96dB/1m spl level and I'm pretty sure the volume knob was not exceeding 11 o'clock position. My amp is a simple Denon 80W AB-class and your Fosi BT20A Pro is a 300W D-class amp, right?. The power seems to be enough to rip the cone out of the speaker basket. The first thing to check would be to see if the source level is matched to the amplifier sensitivity.
Either way, I'm glad you like the sound :).
That was it! I feel so embarrassed. My source volume level was way low. All good now. The speakers continue to sound great (and louder).
 
BTW, I've listened a decent amount and played around a bit on spinorama to compare the estimated in-room to some others I've heard recently. If you've not done this, you owe it to yourself to do so. Here, for example, is it vs. the well regarded KEF Concerto Q Meta. What we're getting for, in my build, $300 worth of parts is astounding. Thank you @XMechanik !

My one tweak would be that they're just a touch dark in my setup. In the VituixCAD project (again - thank you @XMechanik for providing this!), we can see that the target is -0.93 dB/octave for the in-room from 266-15kHz. If you've built it up already and are reaching for just a touch of treble, swapping R3 from 15 ohms to 12 ohms is a very simple fix which turns it to about -0.6 dB/octave. Changing single values in a crossover, especially one this optimized is not to be done lightly. But, the tweeter circuit is far simpler than the woofer and I can't see any bad effects. You get a slight uplift on par with what you might get by a change in angle -- 1-1.5dB. I'd not go further than this as you'll really start to alter the filter.

1741575725615.png
 
I just finished my speakers and they sound very good to my ear. I built them using passive radiators (16g added mass) and the bass is, at least in my small living room, amazing for such a small speaker, going strong to 35Hz. Bass is in the matter of fact too dominant in my listening position and needs to be EQ:d down by a fair amount. Other than that the sound is very very good for the price. My old speakers are Wharfedale Diamond 9.1, but I haven´t yet done a side by side comparison between them. I remember that without EQ Wharfedales sounded very dark and muddy where Mechanos sound very balanced, but I will get to that later.

My Mechanos are built using 16mm MDF with internal bracing. The veneer is curly maple finished with Rubio Monocoat (charcoal). I´m not completely satisfied with the finish, but this has to do for now. I bought the veneer from a shop cutted to proper size and they used 3 sheets glued together. Also I should have first stained the veneer black and then use clear on top of it. Now the three pieces are too visible for my taste and they are a little blotchy too. This was my first full range speaker buid, so I´m still learning. I have done a few subwoofers in my younger days, but I didn´t care about the finish so much at the time.
 

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I just finished my speakers and they sound very good to my ear. I built them using passive radiators (16g added mass) and the bass is, at least in my small living room, amazing for such a small speaker, going strong to 35Hz. Bass is in the matter of fact too dominant in my listening position and needs to be EQ:d down by a fair amount. Other than that the sound is very very good for the price. My old speakers are Wharfedale Diamond 9.1, but I haven´t yet done a side by side comparison between them. I remember that without EQ Wharfedales sounded very dark and muddy where Mechanos sound very balanced, but I will get to that later.

My Mechanos are built using 16mm MDF with internal bracing. The veneer is curly maple finished with Rubio Monocoat (charcoal). I´m not completely satisfied with the finish, but this has to do for now. I bought the veneer from a shop cutted to proper size and they used 3 sheets glued together. Also I should have first stained the veneer black and then use clear on top of it. Now the three pieces are too visible for my taste and they are a little blotchy too. This was my first full range speaker buid, so I´m still learning. I have done a few subwoofers in my younger days, but I didn´t care about the finish so much at the time.
I really like that finish TBH. I’ve got a couple sheets of maple I was going to use on my build and may go with that charcoal finish.
 
Hello friends,

For no particular reason, other than the challenge, I want to build the crossover networks using off-the-shelf components from reputable manufacturers (panasonic, nichicon, ...).
However, I've run into a design decision that I lack the experience to make.

Panasonic provides PP film capacitors for all required values up to and including 6.8 microfarad (250 VDC rated) no problems there. For the bigger capacitances I've reasoned bi-polar electrolytics might be a good choice. Nichicon provides such capacitors specifically meant for crossover networks but they're E6 valued and have a max rating of 50 VDC. I'm basically wondering if I'm going to pop these capacitors at some point if I were to go for some parallel configuration in order to achieve the designed-for values.
 
Hello friends,

For no particular reason, other than the challenge, I want to build the crossover networks using off-the-shelf components from reputable manufacturers (panasonic, nichicon, ...).
However, I've run into a design decision that I lack the experience to make.

Panasonic provides PP film capacitors for all required values up to and including 6.8 microfarad (250 VDC rated) no problems there. For the bigger capacitances I've reasoned bi-polar electrolytics might be a good choice. Nichicon provides such capacitors specifically meant for crossover networks but they're E6 valued and have a max rating of 50 VDC. I'm basically wondering if I'm going to pop these capacitors at some point if I were to go for some parallel configuration in order to achieve the designed-for values.
It looks like you are on the safe side with 50V capacitors. With 20V RMS voltage at the terminal this limit won't be exceeded. There's a great tool in VituixCad called "Power dissipation" that can be configured to show the peak voltage on capacitors. The only capacitor with the 50V limit exceeded (@4kHz) is 0.82uF which won't be bipolar I suppose.

50v_caps.png
 
It looks like you are on the safe side with 50V capacitors. With 20V RMS voltage at the terminal this limit won't be exceeded. There's a great tool in VituixCad called "Power dissipation" that can be configured to show the peak voltage on capacitors. The only capacitor with the 50V limit exceeded (@4kHz) is 0.82uF which won't be bipolar I suppose.

View attachment 436428
Awesome! Thank you!
 
It looks like you are on the safe side with 50V capacitors. With 20V RMS voltage at the terminal this limit won't be exceeded. There's a great tool in VituixCad called "Power dissipation" that can be configured to show the peak voltage on capacitors. The only capacitor with the 50V limit exceeded (@4kHz) is 0.82uF which won't be bipolar I suppose.

View attachment 436428

Hi XMechanik,

Just out of interest, would you plot the same graph but select Pink Noise above 2000Hz and a Crest factor of 13dB? I'm curious what that does to the peak voltage on the 0.82uF cap.
 
Hi XMechanik,

Just out of interest, would you plot the same graph but select Pink Noise above 2000Hz and a Crest factor of 13dB? I'm curious what that does to the peak voltage on the 0.82uF cap.
here it is:
pink.png
 
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