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After working on a new prototype for the Directiva R2 project (which did not make the cut as a cardioid design), I found it wasteful to throw the cabinets out. So I converted them into a sealed version instead.
Since these actually turned out performing very well, I’ve decided to share the plans and data with everyone in case you’re looking for a small, sealed monitor. These work great as a standalone LS3/5a-type monitor. You can also combine them with a sub for a potent 2.1 system, or even use them as the 2-way in a 3-way setup with a custom bass module.
I will share both a passive and an active version, although you can use the data to build whatever you prefer.
For my own builds, I started with a hybrid version using a 7-part crossover that requires DSP. Since then, I’ve developed a full passive crossover with only 3 additional parts. This means you don’t need any DSP to run these speakers. I’ve also included some suggested PEQ filters to smooth the response even further.
Impedance never drops below 4 ohms, so these can be driven by pretty much any amplifier.
Dimensions are 29cm (h) * 18cm * 18cm (based on 18mm sheets)
Active or passive?
While I'm a fan of active loudspeakers, personally, I think the passive version works very well. Unless you have DSP and amp channels to spare, I see little reason to go fully active.
Passive components also provide a safety net for the tweeter, and the system is much less prone to noise. These speakers are dead quiet.
Due to the unusual shape, this design requires some CNC work or 3D printing as an alternative. I’m still looking for someone willing to create a printable design based on my drawings. If you have spare time and skills, feel free to get in touch.
Everything is based on 18 mm sheets (3/4" is also fine, it will add some marginal depth). The baffle needs a generous 1" roundover to minimize diffraction effects.
The terminal cutout on the rear panel is designed for a specific terminal that allows bi-amping or full active use. You can of course use any terminals you like, just adjust the cutout accordingly.
Drivers:
Parts per speaker:
Plans and data:
All files, drawings, and measurements are available in this folder: Directiva R2.5 Plans & Data
Thanks:
Big thanks as well to all Directiva R2 team members! While this particular version was an improvised solo endeavour, the basis in terms of driver selection and enclosure design still came out of a team effort.
Also a very big thanks to the creators of ARTA (Ivo Mateljan) and VituixCad (Kimmo Saunisto) - how great is it that we have free access to software of this kind?
Closing thoughts:
Feel free to have some fun with the data. Real world results match the simulations very well, so you can adjust anything to taste, or design your own filter from scratch.
With the suggested crossovers in place, unlike many popular 2-ways, overall directivity slope is not too steep, and follows the suggested slopes quite well. Subjectively, it does sound good for casual listening far outside of the sweet spot as well (tonally speaking).
Since these actually turned out performing very well, I’ve decided to share the plans and data with everyone in case you’re looking for a small, sealed monitor. These work great as a standalone LS3/5a-type monitor. You can also combine them with a sub for a potent 2.1 system, or even use them as the 2-way in a 3-way setup with a custom bass module.
I will share both a passive and an active version, although you can use the data to build whatever you prefer.
For my own builds, I started with a hybrid version using a 7-part crossover that requires DSP. Since then, I’ve developed a full passive crossover with only 3 additional parts. This means you don’t need any DSP to run these speakers. I’ve also included some suggested PEQ filters to smooth the response even further.
Impedance never drops below 4 ohms, so these can be driven by pretty much any amplifier.
Dimensions are 29cm (h) * 18cm * 18cm (based on 18mm sheets)
Active or passive?
While I'm a fan of active loudspeakers, personally, I think the passive version works very well. Unless you have DSP and amp channels to spare, I see little reason to go fully active.
Passive components also provide a safety net for the tweeter, and the system is much less prone to noise. These speakers are dead quiet.
Due to the unusual shape, this design requires some CNC work or 3D printing as an alternative. I’m still looking for someone willing to create a printable design based on my drawings. If you have spare time and skills, feel free to get in touch.
Everything is based on 18 mm sheets (3/4" is also fine, it will add some marginal depth). The baffle needs a generous 1" roundover to minimize diffraction effects.
The terminal cutout on the rear panel is designed for a specific terminal that allows bi-amping or full active use. You can of course use any terminals you like, just adjust the cutout accordingly.
Drivers:
- Tweeter: SEAS 27TBCD/GB-DXT
- Woofer: SB Acoustics SB15NBAC30-8
Parts per speaker:
- 1 × baffle
- 1 × rear plate
- 8 × center pieces
Plans and data:
All files, drawings, and measurements are available in this folder: Directiva R2.5 Plans & Data
Thanks:
Big thanks as well to all Directiva R2 team members! While this particular version was an improvised solo endeavour, the basis in terms of driver selection and enclosure design still came out of a team effort.
Also a very big thanks to the creators of ARTA (Ivo Mateljan) and VituixCad (Kimmo Saunisto) - how great is it that we have free access to software of this kind?
Closing thoughts:
Feel free to have some fun with the data. Real world results match the simulations very well, so you can adjust anything to taste, or design your own filter from scratch.
With the suggested crossovers in place, unlike many popular 2-ways, overall directivity slope is not too steep, and follows the suggested slopes quite well. Subjectively, it does sound good for casual listening far outside of the sweet spot as well (tonally speaking).
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