Hi Forum
Warning: there is no such thing as "the beste (NOT, as in limited LF) full range Speaker in the world".
But the title sounds nice as a follow up of the previous thread. And like my previous design it is all about what compromises you want to make.
It has been over 6 years ago that I build that big 3 way speaker, together with my friend Joost who made the small two way that I also build as surrounds with Atmos upfiring section
"building the best 3-way full range speaker"
Earlier this year we did a big renovation of the living room with attached kitchen and when this was done, I found the speakers a big too massive.
Maybe it is my age and the testosterone is diminishing but the speakers always were big.
So I am starting a new design, with 20% smaller footprint and 30% less volume.
Still a large speaker but a bit better suited to the room and in this thread I would like to share this journey with you.
What did I do so far.
Wel in this design I want to be capable of simulating and measuring better to help tweak the end result with less trial and error.
For enclosure simulation and filter design I will use VituixCAD (with a well deserved donation when it all works as displayed)
For measurements most likely Arta
And to make sure that what we measure is accurate I bought an EarthWorks M23R and built a nice mic stand that should be close to the ideal setup.
The stand is described here:
The Ultimate Speaker Measurement Setup
A smaller speaker will be more limited in its LF performance, and that means a dual 8" instead of the original dual 10"
An 8" woofer will cross better to a 5" midrange then the previous 6" and also can live in a smaller enclosure.
The tweeter is to me still a beauty so it remains the same but might be crossed a bit higher
So the following units are selected and ordered:
The underhung magnet construction should improve linearity and the smaller lighter cone will improve speed compared to the 18 H 52 17 06 SDKA that I used in the big speaker. the later was ordered with an Re of 7,5 ohm as was the 10" 10 C 77 25 10 KAP I used in the big design.
This selection comes with a few new design challenges.
multi layers of MDF and HDF, and for now a baffle milled out of a solid 40mm thick aluminum slab
10 pieces metal 8 mm rods that span the baffle with the rear to remove all fibrations by adding a tension on the total enclosure.
This is all copy and paste from something that worked very well.
The next challenge is to learn a 3D program (Fusion360) a I need a .step file so the CNC company can cut the front panel to the right size with the right diffraction preventing curves.
So I do not expect an update soon.
Cheers,
Peter
Warning: there is no such thing as "the beste (NOT, as in limited LF) full range Speaker in the world".
But the title sounds nice as a follow up of the previous thread. And like my previous design it is all about what compromises you want to make.
It has been over 6 years ago that I build that big 3 way speaker, together with my friend Joost who made the small two way that I also build as surrounds with Atmos upfiring section
"building the best 3-way full range speaker"
Earlier this year we did a big renovation of the living room with attached kitchen and when this was done, I found the speakers a big too massive.
Maybe it is my age and the testosterone is diminishing but the speakers always were big.
So I am starting a new design, with 20% smaller footprint and 30% less volume.
Still a large speaker but a bit better suited to the room and in this thread I would like to share this journey with you.
What did I do so far.
Wel in this design I want to be capable of simulating and measuring better to help tweak the end result with less trial and error.
For enclosure simulation and filter design I will use VituixCAD (with a well deserved donation when it all works as displayed)
For measurements most likely Arta
And to make sure that what we measure is accurate I bought an EarthWorks M23R and built a nice mic stand that should be close to the ideal setup.
The stand is described here:
The Ultimate Speaker Measurement Setup
A smaller speaker will be more limited in its LF performance, and that means a dual 8" instead of the original dual 10"
An 8" woofer will cross better to a 5" midrange then the previous 6" and also can live in a smaller enclosure.
The tweeter is to me still a beauty so it remains the same but might be crossed a bit higher
So the following units are selected and ordered:
- Dual Audio Technology Flex unit 8 H 77 20 06 SDKA
- Dual Audio Technology C-Quenze 15 H 52 06 13 SDKA-LR (so without the M surround as this one has a lower Fs)
- Scan Speak D29080714000
The underhung magnet construction should improve linearity and the smaller lighter cone will improve speed compared to the 18 H 52 17 06 SDKA that I used in the big speaker. the later was ordered with an Re of 7,5 ohm as was the 10" 10 C 77 25 10 KAP I used in the big design.
This selection comes with a few new design challenges.
- The midrange with its underhung motor cannot be ordered with a higher Re, so the two units in parallel will have an Re of around 2,7 Ohm
- These midranges have a higher efficiency and I want to use that to make the end result a >92dB @ 2.83V
- The tweeters low end will match that but the design will most likely have a slight roll off above 10k what in practice is also a normal design criteria
- The woofers will have a hard time catchup up with the MF/HF set so it will be powered by a Hypex module with DSP section
- You can tweak the volume to keep up with the very efficient MF units
- You can add room correction without the risk to ruin your high end frontend (DAC/Phono/Pre/Power) as the important MF HF section does not need to pass a low cost ADC/DAC that is part of the plate-amp.
- The big impedance peak at 15Hz and and mainly the one at 60Hz (enclosure tuned at 30Hz) of about 20 Ohm would make a passive low pass filter complex and bulky. This all is not needed with the DSP filter section that is only used for the woofers
- The cost of serious LF filter parts is also substantial and I think the plate amp will be only mildly more expensive
- The Re of 2,7 ohm is fine for this nCore based amp with still 400 Watt @ 2 Ohm
multi layers of MDF and HDF, and for now a baffle milled out of a solid 40mm thick aluminum slab
10 pieces metal 8 mm rods that span the baffle with the rear to remove all fibrations by adding a tension on the total enclosure.
This is all copy and paste from something that worked very well.
The next challenge is to learn a 3D program (Fusion360) a I need a .step file so the CNC company can cut the front panel to the right size with the right diffraction preventing curves.
So I do not expect an update soon.
Cheers,
Peter
Last edited:
Hi Forum,
During my holiday I tasked myself in learning Fusion360 to help me model a front baffle with some angles and curves.
This is the flat drawing as a first concept.
The 3D render of the end result.
The render of the aluminum base
The front baffle that will be machined from a solid billet of aluminium.
The two midrange units are placed under an angle helping the d'appolito arrangement and moving the tweeter backwards without having any stubs that could influence the diffraction.
The rear side of the baffle with the flowerlike cutout behind the midrange to give it "breathing space" as the magnet would block the airflow with such a thick baffle.
And this is a vertical cut trough the internal construction.
And some horizontal cuts
The (end of life) beryllium tweeters are sourced and already in house. The Audio Technology drivers are ordered and on its way.
So the building of the enclosure can start soon.
So far an update on the still theoretical design work
Cheers,
During my holiday I tasked myself in learning Fusion360 to help me model a front baffle with some angles and curves.
This is the flat drawing as a first concept.
The 3D render of the end result.
The render of the aluminum base
The front baffle that will be machined from a solid billet of aluminium.
The two midrange units are placed under an angle helping the d'appolito arrangement and moving the tweeter backwards without having any stubs that could influence the diffraction.
The rear side of the baffle with the flowerlike cutout behind the midrange to give it "breathing space" as the magnet would block the airflow with such a thick baffle.
And this is a vertical cut trough the internal construction.
And some horizontal cuts
The (end of life) beryllium tweeters are sourced and already in house. The Audio Technology drivers are ordered and on its way.
So the building of the enclosure can start soon.
So far an update on the still theoretical design work
Cheers,
No I didn't, it is an evolution of the original design that ended up very flat. The crossover frequencies will be a bit higher due to the smaller driver, but maybe not. measurements and final tweaking will be a lengthy task
A small update:
The drivers have arrived and look great. The built quality is fantastic as always.
I have been putting some extra hours in Fusion 360, and although I still run into things I cannot explain I am getting better in it.
So I have put all flat panels into Fusion, and check if it all fits.
This has brought some errors to the surface so a good check, I also tried to make the speakers units in Fusion to make some renders of the final result,
The base is still under construction but this is the direction I want to go.
The drivers have arrived and look great. The built quality is fantastic as always.
I have been putting some extra hours in Fusion 360, and although I still run into things I cannot explain I am getting better in it.
So I have put all flat panels into Fusion, and check if it all fits.
This has brought some errors to the surface so a good check, I also tried to make the speakers units in Fusion to make some renders of the final result,
The base is still under construction but this is the direction I want to go.
For someone who just started working with Fusion360 a month ago, your 3D renders are amazing! I might have to follow in your footsteps re- the software.
Too thin IMO. The steel rods will be tensioned like strings so are prone to resonate. I would go 2-3 times as thick - what diameter does Magico use, since they came up with this construction approach afaik?
Nice project! I like minimal compromise speaker designs. The "take no prisoners" approach is very close to my heart. Those AT drivers have the potential to sound very neutral in that setup. Hopefully the front baffle will work out the way you envision it. The biggest obstacle you'll face with those AT drivers is working through the surround to cone reflections which are pronounced with the smaller cone drivers. Thats honestly my only gripe with AT chassis. They need alot of preconditioning before measuring them for the final crossover design.
When you find out how much those 8" woofers sell for, the "reasonable" may no longer be as stated for the majority of us.