Directiva r2 monitor prototype build

[tehas]

Great ! Appreciate that it will be a much more affordable build than with the Purifi

 

[DualTriode]

Hello Rick and All,

I think of this a pushing the DIY envelope, doing the best that we can and testing the results.

If you want an affordable build then set a maximum price limit.

There should be some testing going in, simulations may help to a limited extent.

Just for grins I did some testing of the SB Acoustics 5 inch and the Purifi 6-1/2 inch drivers both in a closed Denovo 0.55 cubic foot flat pack enclosure. (quick and easy)

The Purifi driver has 10 to 20dB's better distortion performance across the frequency response.

An affordable build has its' price.

See the attached test plots.

Thanks DT

 

[jmf11]

Hello,

Some news about the project? Did you had some tests and measurements? Would be happy to learn if there are progress to expect in coming monthes.

JMF

 

[Rick Sykora]

Am still (slowly) working on the bass module and am playing around with a cheaper woofer for r1.

The design lead for r2 had newborn earlier this year and his wife had complications. He has been full time on taking care of them but expects he will be able to get back to r2 soon. Once he finalizes his design, I will build a set and (if small enough) send to Amir for review.

 

[D!sco]

I always feel like I'm holding my breath trying to be patient for this project. I'm so sorry to hear about the team, I hope whoever's wife gets better soon.

How far do you think the project is along? I've seen enough ancillary data from Fluid's and TimVG's other posts to think it should be nearly done, but the devil is always in the details. Have you picked a pair of resonant frequencies for the cardioid effect in both the monitor and the bass module?

 

[jmf11]

Thank you for the feedback Rick. This is a really interesting project, as would also be the cheaper woofer for r1.

We stay tuned ;-)

 

[Rick Sykora]

I always feel like I'm holding my breath trying to be patient for this project. I'm so sorry to hear about the team, I hope whoever's wife gets better soon.

Thanks, this unfortunately is the reality of volunteer projects. Was really fortunate that r1 went so well…

How far do you think the project is along? I've seen enough ancillary data from Fluid's and TimVG's other posts to think it should be nearly done, but the devil is always in the details. Have you picked a pair of resonant frequencies for the cardioid effect in both the monitor and the bass module?

I think the monitor is well along but needs a woofer for real bass when no bass module is used. Am not sure how it will be integrated with the existing design.

The cardioid version of the bass module is on hold for now. Was unable to make it work with the cabinet and woofers I have. I would still like to do but am thrashing a bit currently and so it needs to wait.

 

[D!sco]

I don't think I've seen a cardioid do bass without being a 3-way. Sounds like a tough challenge to solve in the consumer market.

 

[TimVG]

The monitor has been refined some more since the very promising prototype in terms of cabinet design only. The only thing remaining is to build it, measure it, implement the crossover and couple it to a bass module. Since the bass module can be many things, I will build a basic monopole column, probably bass reflex. I may not be able to provide a full spin as the vertical plane may prove tricky with 1) seperate enclosures and 2) balancing the monitor without affecting the vents.

I had inquired in the beginning of the project with Klippel Germany, but at over €1000 having it measured is not feasable. Sadly no hobbyists as far as I'm aware with an NFS in Europe.

 

[kleinjoshuaa]

Really excited to see this come to fruition. Will it still be possible to build this from a flat pack kit? I really like that was part of the directiva r1.

 

[Rick Sykora]

Really excited to see this come to fruition. Will it still be possible to build this from a flat pack kit? I really like that was part of the directiva r1.

Directiva r1 targeted a simple flatpack from the start. r2 is meant to strive further and so uses a custom cabinet. Likely it could be built using a rectangular enclosure, but would not be optimal. Nor am I aware if any flat pack available that would come close to the needed volume.

If there is enough interest, might fund a flat pack run. Otherwise, there are a number of custom cabinet builders that can do. Once we get the design completed and tested, can consider options.

 

[kleinjoshuaa]

Directiva r1 targeted a simple flatpack from the start. r2 is meant to strive further and so uses a custom cabinet. Likely it could be built using a rectangular enclosure, but would not be optimal. Nor am I aware if any flat pack available that would come close to the needed volume.

If there is enough interest, might fund a flat pack run. Otherwise, there are a number of custom cabinet builders that can do. Once we get the design completed and tested, can consider options.

Very cool - I've built my own boxes a few times. This design looks a bit more complex, but I figure with part dimensions and a plan I could make it work.

Like everyone else - super excited to see the directiva r2 come to fruition

 

[somebodyelse]

If there is enough interest, might fund a flat pack run. Otherwise, there are a number of custom cabinet builders that can do. Once we get the design completed and tested, can consider options.

Another option is to share design files so people could get the CNC work done locally, assuming we have someone with the required expertise. I've done some small scale stuff for my own use, but a pro would probably break down laughing/crying!

 

[Madjalapeno]

Another option is to share design files so people could get the CNC work done locally, assuming we have someone with the required expertise. I've done some small scale stuff for my own use, but a pro would probably break down laughing/crying!

I'm a CAD monkey and can make you DXF files for getting parts made if it would help?

 

[TimVG]

@Madjalapeno I do my cutouts with a Shaper Origin which works from svg files. I'm still working on the drawings (in Illustrator) but remember having some minor issues last time of dimensions fluctuating ever so slightly in the drawings themselves despite being setup correctly initially, still need to work that out. If I don't get it sorted out in the next two weeks would appreciate someone being able to take a look.

 

[somebodyelse]

I'm a CAD monkey and can make you DXF files for getting parts made if it would help

Thanks for the offer. I mostly use FreeCAD for my tool path generation, and have exported to DXF for a local place to import into VCarve for larger stuff. Is DXF the standard interchange format for CNC routing? Like @TimVG I have had 'fun' with quirks of DXF versions and different applications' handling of importing and exporting them.

 

[Madjalapeno]

@Madjalapeno I do my cutouts with a Shaper Origin which works from svg files. I'm still working on the drawings (in Illustrator) but remember having some minor issues last time of dimensions fluctuating ever so slightly in the drawings themselves despite being setup correctly initially, still need to work that out. If I don't get it sorted out in the next two weeks would appreciate someone being able to take a look.

I'm using Solidworks, and everything is parametric, so very easy to change.

 

[Kwesi]

Hi, I really love that project as I know and like the driver combination well:

What I can suggest from experience for improvements is:

The SB has a bit weak magnetic circuit, you can push it in the fundamentals and lower distortion a little with an additional magnet that helps to saturate the lower pole plate and increase BL and the sensitivity.

Put an LC notch in series tuned to the high Q membran brakeup to block the current distortion harmonics at this frequency. Especially to the midrange, and especially with an active crossover.

Best regards
Peter

 

[J49]

Hi Directiva team. Long time lurker here, first time poster. Any updates to share on R2?! Would you consider releasing plans for the cardioid monitor sans bass module if that part is finished first? Thanks for all your work on this project. Looking forward to building one when its posted.

 

[Rick Sykora]

Hi Directiva team. Long time lurker here, first time poster. Any updates to share on R2?! Would you consider releasing plans for the cardioid monitor sans bass module if that part is finished first? Thanks for all your work on this project. Looking forward to building one when its posted.

The bass module(s) are not a major show stopper but finalizing the monitor design specifics has been. One issue has been whether the final design will incorporate a woofer for bass without the bass module. If you want to simply build the original 2-way prototype, can post the specs for it. It could be used with subwoofer(s) for bass.