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horias2000

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I really wanted to try the new MD60N-6 dome mid from SB Acoustics. I was looking at it for a while and I hoped it will have a discount at some point but no such luck. I then decided to buy it and build a pair of tower speakers. For the low end I chose the MW19P-8 woofer as it had great reviews and the spec sheet is really good. I wanted to do a project with this woofer for may years as well. I had a pretty difficult time choosing the tweeter for this project. The Satori TW29RN-B-8 Ring Dome Tweeter was an obvious option but I read an article about one of the best tweeters around, money no object, (at least that is what the reviewers were saying). It's the Bliesma T25B-6, a beryllium dome tweeter that was around 5-600EUR a pair!!! So really good price for a beryllium tweeter. Unfortunately this was exactly around the time when Bliesma announced that their beryllium diaphragm supplier will no longer be able to supply them with the parts. That meant that the T25B-6 was nowhere in sight. I then decided to go ahead and buy the T25S-6, a silk dome tweeter that was identical in size t the beryllium one and it also had great reviews.
I did a lot of simulations for the crossover filter and I ended up using 600Hz and 3kHz as crossover frequencies. The filter itself is a LR2 topology and it is rather straight forward. This is what the filter was looking like after I simulated it based on datasheet specs:

1709928530801.png


After I received the drivers and I was able to put the enclosures together, I measured each driver on the final baffle and then I used that frequency response to adjust the filter. I also measured the distance between the acoustical centers of the tweeter and the mid dome using the microphone at 1m distance. As the mid driver is a dome, the acoustical center was only 1mm away from the tweeter's acoustical center and I did not have to spend to much time trying to time align the two drivers.
I proceeded to build a mock-up of the filters and I did many, many measurements. All of these were performed in my living-room as I do not have a dedicated workshop for this. The room itself has acoustic treatment but I still have a room mode at ~200Hz and another one at ~500Hz. So the dips at these frequencies are due to the room modes.
After some tweaking, I ended up with the frequency response seen below:

Satori_Bliesma_tower_final_xover.jpg
This is measured at 1m on the tweeter axis. I'm pretty happy with the result. Sound wise, I was surprised to hear how much detail the tweeter and the mid dome were able to send my way. So much so that I had the impression the tweeter was a bit too high level wise. I tried attenuating it a bit more but I did not like it that way. In the end I left it as it was and it will be this way for a few weeks/months. I made the enclosure in such a way that the filter can be easily accessed by setting the speaker on one side. The filters are on the bottom of the enclosure. This means that I will definitely tweak them in the future.
Distortion wise, the measurement looks really nice. I was expecting low distortion from all three drivers and I was not disappointed.

Satori_Bliesma_tower_final_thd.jpg

Satori_Bliesma_tower_final_thd_1.jpg

I also used my DATS v3 to measure the impedance of the final speaker and there were no surprises here either.

Satori_Bliesma_tower_final_imp.JPG


The enclosures are ported and tuned to ~37Hz. I used three horizontal internal braces. I've put felt on the internal walls and acoustic damping material (the white fluffy stuff).
I'm very happy how these speakers measure and how they sound. I will most probably paint the enclosures black at some point, but for now I'll just listen to them for a while.
For measuring the speakers I used an UMIK-1 microphone and for simulating the filter I used LinearX Crossover Shop and VituixCAD.

Satori_Bliesma_tower_final_nearfield.jpg


Untitled.jpg


Untitled_2.jpg
 

DVDdoug

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Nice job!

I will most probably paint the enclosures black at some point,
I usually cover my DIY speakers in leather-look viny (like they use on guitar amplifiers). Normally I use brown but I've used black one once I used white with black grill cloth. It's inexpensive, fairly easy (a LOT easier than a furniture-like wood finish), and resistant to scratches & cosmetic damage.

...Just an option for you to consider.
 

kemmler3D

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Very cool and good result.

I would love to see some off-axis measurements, since with both the dome mid and the Bliesma tweeter, you have a lot of the frequency range covered by higher-profile-than-normal drivers. IIRC the Bliesma tweeters are pretty wide because of a higher-than-normal profile. At least I know that was true of the Be one. I would expect the radiation pattern to look somewhat different from what we normally see measured around here.

That might also explain the perception of "extra detail" - the on-axis looks flat but I'd bet money the power response shows slightly elevated mid and treble due to the dome and tweeter having wide dispersion. (a guess.)

Also, that's an impressively flat response for such a high crossover IMO. Nice work.
 
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horias2000

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Very cool and good result.

I would love to see some off-axis measurements, since with both the dome mid and the Bliesma tweeter, you have a lot of the frequency range covered by higher-profile-than-normal drivers. IIRC the Bliesma tweeters are pretty wide because of a higher-than-normal profile. At least I know that was true of the Be one. I would expect the radiation pattern to look somewhat different from what we normally see measured around here.

That might also explain the perception of "extra detail" - the on-axis looks flat but I'd bet money the power response shows slightly elevated mid and treble due to the dome and tweeter having wide dispersion. (a guess.)

Also, that's an impressively flat response for such a high crossover IMO. Nice work.
I plan to perform some off-axis measurements as well but at the moment itțs really hard to do. I want to build a jig that will allow me to rotate the speaker 10 degrees at a time. For now I use my living-room for building and measuring and it's really hard to work with two kids roaming around :). Hopefully I can find a place to rent that I can use as a workshop.
 
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horias2000

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Who care for the paint with such beautiful measurements ?
Really impressive work for a diy project !
Are you in the speaker / acoustic business ?
Whatever it's well done !
Thanks! I'm not in acoustic business. By trade I'm an electronics design engineer and I;m really into audio electronics. I've also posted several amplifier builds here. As for speakers, I've built several projects. I think I've built around 10 or 11 speakers so far. I started out of curiosity a while ago. I had the money to buy some nice bookshelf speakers but I decided to buy drivers and crossover parts instead :). Since then I've been building my own speakers and I've built for some friends as well. The two way ones that can be seen in one of the photos are also made by me and I've been using them for 7-8 years now. For the towers, I wanted to try the higher end drivers. I will most probably stick with these for a while now.
 

lemmy_collins

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Thanks! I'm not in acoustic business. By trade I'm an electronics design engineer and I;m really into audio electronics. I've also posted several amplifier builds here. As for speakers, I've built several projects. I think I've built around 10 or 11 speakers so far. I started out of curiosity a while ago. I had the money to buy some nice bookshelf speakers but I decided to buy drivers and crossover parts instead :). Since then I've been building my own speakers and I've built for some friends as well. The two way ones that can be seen in one of the photos are also made by me and I've been using them for 7-8 years now. For the towers, I wanted to try the higher end drivers. I will most probably stick with these for a while now.
You're the one to follow !
 

alex-z

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If those are in-room measurements without gating that would explain why you found the tweeter level too high. It appears everything above about 600Hz is elevated by 2dB.

Typically you want a flat response from around 100-1000Hz, then a gradual decline towards 20000Hz. There is obviously some personal preference involved, I usually start with .7dB per octave and increase as needed.
 

dualazmak

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Thank you for sharing your wonderful DIY speaker project.

Do you have any plan to make the speaker drivers fully active by eliminating all the passive LCR network, and to directly drive each of the SP drivers (units) by dedicated amplifier to go into DSP-based multichannel multi-SP-driver multi-amplifier fully active stereo audio system?
Just for your reference, you can find here the latest setup of my DSP-based multichannel audio system.
The total signal path is like this;
WS00006960.JPG


My recent post here would be also of your reference and interest.
 
Last edited:

Lao Lu

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I really wanted to try the new MD60N-6 dome mid from SB Acoustics. I was looking at it for a while and I hoped it will have a discount at some point but no such luck. I then decided to buy it and build a pair of tower speakers. For the low end I chose the MW19P-8 woofer as it had great reviews and the spec sheet is really good. I wanted to do a project with this woofer for may years as well. I had a pretty difficult time choosing the tweeter for this project. The Satori TW29RN-B-8 Ring Dome Tweeter was an obvious option but I read an article about one of the best tweeters around, money no object, (at least that is what the reviewers were saying). It's the Bliesma T25B-6, a beryllium dome tweeter that was around 5-600EUR a pair!!! So really good price for a beryllium tweeter. Unfortunately this was exactly around the time when Bliesma announced that their beryllium diaphragm supplier will no longer be able to supply them with the parts. That meant that the T25B-6 was nowhere in sight. I then decided to go ahead and buy the T25S-6, a silk dome tweeter that was identical in size t the beryllium one and it also had great reviews.
I did a lot of simulations for the crossover filter and I ended up using 600Hz and 3kHz as crossover frequencies. The filter itself is a LR2 topology and it is rather straight forward. This is what the filter was looking like after I simulated it based on datasheet specs:

View attachment 355085

After I received the drivers and I was able to put the enclosures together, I measured each driver on the final baffle and then I used that frequency response to adjust the filter. I also measured the distance between the acoustical centers of the tweeter and the mid dome using the microphone at 1m distance. As the mid driver is a dome, the acoustical center was only 1mm away from the tweeter's acoustical center and I did not have to spend to much time trying to time align the two drivers.
I proceeded to build a mock-up of the filters and I did many, many measurements. All of these were performed in my living-room as I do not have a dedicated workshop for this. The room itself has acoustic treatment but I still have a room mode at ~200Hz and another one at ~500Hz. So the dips at these frequencies are due to the room modes.
After some tweaking, I ended up with the frequency response seen below:

View attachment 355088This is measured at 1m on the tweeter axis. I'm pretty happy with the result. Sound wise, I was surprised to hear how much detail the tweeter and the mid dome were able to send my way. So much so that I had the impression the tweeter was a bit too high level wise. I tried attenuating it a bit more but I did not like it that way. In the end I left it as it was and it will be this way for a few weeks/months. I made the enclosure in such a way that the filter can be easily accessed by setting the speaker on one side. The filters are on the bottom of the enclosure. This means that I will definitely tweak them in the future.
Distortion wise, the measurement looks really nice. I was expecting low distortion from all three drivers and I was not disappointed.

View attachment 355091
View attachment 355092
I also used my DATS v3 to measure the impedance of the final speaker and there were no surprises here either.

View attachment 355093

The enclosures are ported and tuned to ~37Hz. I used three horizontal internal braces. I've put felt on the internal walls and acoustic damping material (the white fluffy stuff).
I'm very happy how these speakers measure and how they sound. I will most probably paint the enclosures black at some point, but for now I'll just listen to them for a while.
For measuring the speakers I used an UMIK-1 microphone and for simulating the filter I used LinearX Crossover Shop and VituixCAD.

View attachment 355099

View attachment 355101

View attachment 355102
I really wanted to try the new MD60N-6 dome mid from SB Acoustics. I was looking at it for a while and I hoped it will have a discount at some point but no such luck. I then decided to buy it and build a pair of tower speakers. For the low end I chose the MW19P-8 woofer as it had great reviews and the spec sheet is really good. I wanted to do a project with this woofer for may years as well. I had a pretty difficult time choosing the tweeter for this project. The Satori TW29RN-B-8 Ring Dome Tweeter was an obvious option but I read an article about one of the best tweeters around, money no object, (at least that is what the reviewers were saying). It's the Bliesma T25B-6, a beryllium dome tweeter that was around 5-600EUR a pair!!! So really good price for a beryllium tweeter. Unfortunately this was exactly around the time when Bliesma announced that their beryllium diaphragm supplier will no longer be able to supply them with the parts. That meant that the T25B-6 was nowhere in sight. I then decided to go ahead and buy the T25S-6, a silk dome tweeter that was identical in size t the beryllium one and it also had great reviews.
I did a lot of simulations for the crossover filter and I ended up using 600Hz and 3kHz as crossover frequencies. The filter itself is a LR2 topology and it is rather straight forward. This is what the filter was looking like after I simulated it based on datasheet specs:

View attachment 355085

After I received the drivers and I was able to put the enclosures together, I measured each driver on the final baffle and then I used that frequency response to adjust the filter. I also measured the distance between the acoustical centers of the tweeter and the mid dome using the microphone at 1m distance. As the mid driver is a dome, the acoustical center was only 1mm away from the tweeter's acoustical center and I did not have to spend to much time trying to time align the two drivers.
I proceeded to build a mock-up of the filters and I did many, many measurements. All of these were performed in my living-room as I do not have a dedicated workshop for this. The room itself has acoustic treatment but I still have a room mode at ~200Hz and another one at ~500Hz. So the dips at these frequencies are due to the room modes.
After some tweaking, I ended up with the frequency response seen below:

View attachment 355088This is measured at 1m on the tweeter axis. I'm pretty happy with the result. Sound wise, I was surprised to hear how much detail the tweeter and the mid dome were able to send my way. So much so that I had the impression the tweeter was a bit too high level wise. I tried attenuating it a bit more but I did not like it that way. In the end I left it as it was and it will be this way for a few weeks/months. I made the enclosure in such a way that the filter can be easily accessed by setting the speaker on one side. The filters are on the bottom of the enclosure. This means that I will definitely tweak them in the future.
Distortion wise, the measurement looks really nice. I was expecting low distortion from all three drivers and I was not disappointed.

View attachment 355091
View attachment 355092
I also used my DATS v3 to measure the impedance of the final speaker and there were no surprises here either.

View attachment 355093

The enclosures are ported and tuned to ~37Hz. I used three horizontal internal braces. I've put felt on the internal walls and acoustic damping material (the white fluffy stuff).
I'm very happy how these speakers measure and how they sound. I will most probably paint the enclosures black at some point, but for now I'll just listen to them for a while.
For measuring the speakers I used an UMIK-1 microphone and for simulating the filter I used LinearX Crossover Shop and VituixCAD.

View attachment 355099

View attachment 355101

View attachment 355102
Cabinets HxWxD measurements? Looks great!
 

D!sco

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This looks absolutely incredible. That bass response is shockingly low.
I am also super curious about your box and off-axis responses. What made you decide to point the port forward?
 
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horias2000

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If those are in-room measurements without gating that would explain why you found the tweeter level too high. It appears everything above about 600Hz is elevated by 2dB.

Typically you want a flat response from around 100-1000Hz, then a gradual decline towards 20000Hz. There is obviously some personal preference involved, I usually start with .7dB per octave and increase as needed.
The first graph is gated at 3ms as I have the first reflections at 3.5ms (somewhat small room). The distortion graph (the one with the fundamental) is not gated at it's smoothed at 1/12. All measurements are in-room as I do not have other options at the moment.
 
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horias2000

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This looks absolutely incredible. That bass response is shockingly low.
I am also super curious about your box and off-axis responses. What made you decide to point the port forward?
I did not perform off-axis measurements yet as I do not have a good jig to do these measurements. It's something I'll do at some point. As for placing the port on the front, I did not really have a good reason other that me thinking it will look nice. As the port length is rather small (90mm) I can see the stuff that's inside and it might have been better to place it on the back. Also, I've placed the port really close to the side wall and this is not ideal. But considering that I'm listening at low levels, it should not be to big of an issue. The speakers are rarely used at 1W power as I live in a flat and I do not want to bother my neighbors.
 
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horias2000

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Thank you for sharing your wonderful DIY speaker project.

Do you have any plan to make the speaker drivers fully active by eliminating all the passive LCR network, and to directly drive each of the SP drivers (units) by dedicated amplifier to go into DSP-based multichannel multi-SP-driver multi-amplifier fully active stereo audio system?
Just for your reference, you can find here the latest setup of my DSP-based multichannel audio system.
The total signal path is like this;
View attachment 355186

My recent post here would be also of your reference and interest.
That's a great looking implementation you have there. I definitely plan to use DSP to build active crossovers. For now I'm happy with passive filters as I've built several amps (including tube ones) that I plan to use. Having the amp inside means that I can't use my amps :). I definitely plan to use some DSP + class D amps for an active speaker at some point.
 
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horias2000

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I added some extra attenuation on the MID and tweeter. Below you can see the result:

Satori_Bliesma_tower_tuned_lower_MID+TWT_gated_4ms.JPG

This is measured at 1m, gated at 4ms. The green trace is the original xover and the blue one is the updated one. Sound wise I can't say I can hear a big difference.

From the THD graph below we can see that there is still a slight bump from 4kHz to around 9kHz. This is mostly the tweeter and if I attenuate more, the response above 10kHz will go too abruptly down. I can decrease the effect of the RLC placed on the tweeter. For now I'll leave it as it is.

Satori_Bliesma_tower_tuned_lower_MID+TWT_THD.JPG
 

D!sco

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I only ever notice attenuation like that after an hour or more of listening. Then it matters a lot. Last week I pushed my low shelf filter all the way down to 800hz, which is exactly where your responses diverge now. It broke my brain a little realizing that’s about where my internal concept of “midrange” ends.
 

dualazmak

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Very fortunately, in my case, the still amazingly excellent "midrange" 8.8 cm Beryllium dome YAMAHA JA-0801 nicely covers wide range of 500 Hz to 6 kHz in extremely low distortion and high S/N.
 

D!sco

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Pianos-notes-with-their-respective-frequencies.ppm

Not sure if you care, but I found this to be quite interesting and unexpected. Only the top two octaves play fundamentals above 1khz. The rest of the audio spectrum is typically filled with room acoustics and natural harmonics by recordings. By playing C6, you produce 1khz at the fundamental, and harmonics from the instrument and room at 2 and 3khz (and higher). This has really de emphasized mid and treble drivers in my mind and allows me to think of speaker tunings above 1khz as really being adjustable based on need and preference for acoustic information. Always linear, of course, but the line makes so much more sense now.
 
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