Directiva r2 monitor prototype build

[Rick Sykora]

Cut the front baffle. It is about 7.25 inches wide by 12 inches tall…

Will do routing next. May have to wait for weekend as house interior is getting painted this week!

 

[Madjalapeno]

Don't know about anyone else, but I'm excited to see this build.

 

[Rick Sykora]

In the meanwhile, am considering how to nicely construct the side vents. Do not have a CNC and so no layered cabinet approach as @TimVG used.

As for why I have not cut the "wings" off as yet, my router is larger and needs as much base as I can provide to ride one as I make multiple passes to cut out the driver holes.

 

[TimVG]

Get a 1/2" 2-flute cutter and simply make a straight pass for the vents using a guide. Easy peasy!

 

[Madjalapeno]

Table saw and cross cut sled?

 

[Rick Sykora]

Am thinking something like this. Here is lower half of right side:

The middle section could be simply made using 5 pieces. 4 square pegs for the vent spacers and one filler part. Am planning something fancier that could be easily modified to try other vent configurations.

Anyone who has a plunge router might prefer to make one solid piece and cut the slots. Already get enough MDF dust than I like, so if I can avoid deep cuts with a router, I will!

EDIT: pic fixed!

 

[Rick Sykora]

Slow progress here with house project and snow over weekend...

Usually like to route in the garage due to the MDF dust but has been way too cold to do. Going to cut the rest of the box and hope to get a warmer day. Had a couple of warmer days, but still a lot of snow around and having to pile higher!

 

[Trouble Maker]

That's a pretty smart way to allow anyone with a saw (but no plunge router) to build this, make the slots. How would the small 'positive' pieces be secured, is some wood glue enough?

but still a lot of snow around and having to pile higher!

We got about 2" yesterday and currently getting another inch or two today. Did you all get more further north?

We are in the planning stages of a new garage, trying to have a lofted (wood)work shop space, and probably heat/cool the whole space. I can't wait to not need to drag the saws out into the driveway! And be able to work on projects regardless of the weather.

 

[howard416]

Waiting with bated breath

 

[Rick Sykora]

That's a pretty smart way to allow anyone with a saw (but no plunge router) to build this, make the slots. How would the small 'positive' pieces be secured, is some wood glue enough?



We got about 2" yesterday and currently getting another inch or two today. Did you all get more further north?

We are in the planning stages of a new garage, trying to have a lofted (wood)work shop space, and probably heat/cool the whole space. I can't wait to not need to drag the saws out into the driveway! And be able to work on projects regardless of the weather.

Have about 2 feet of snow around and about 4 degrees, so is not going away soon. Not just about me however, the whole team has other projects too!

If anyone watching here has not seen the main thread posts, am in holding pattern while we run sims on the simpler cabinet and make adjustments. A bunch of small changes have added up to affect directivity more than expected. Also, we are getting a better handle on how the slot characteristics affect the end result. The new cabinet is getting good lower frequency results, but the higher ones worsened slightly.

Always good to do as much prototyping as possible in software. Love to build cabinets, but not small variants of the same one over and over again!

 

[Rick Sykora]

Still waiting on a sim to guide the side panel design, so after some other major woodworking, cut the back baffle and prepped for angle cuts…

 

[Rick Sykora]

Some slow progress, but did clip the angle pieces from the back panel...

The sim got done but did not produce the anticipated results. As I looked to cut side pieces, I wondered about 4 slots on our proto vs. larger single one on the D&D 8C. Another sim has been done and shows more promise.

Before I build, want to try some more sims to see if we can get a simpler cabinet design with potentially even better or comparable directivity.

 

[abdo123]

Some slow progress, but did clip the angle pieces from the back panel...

The sim got done but did not produce the anticipated results. As I looked to cut side pieces, I wondered about 4 slots on our proto vs. larger single one on the D&D 8C. Another sim has been done and shows more promise.

Before I build, want to try some more sims to see if we can get a simpler cabinet design with potentially even better or comparable directivity.

Is there something wrong with the current cabinet?

 

[ctrl]

Is there something wrong with the current cabinet?

Rick just wants to make sure the speaker cabinet has the best radiation results with the simplest possible design.
... and I want a design as complex as possible to make a patent application feasible - just kidding!

So I'm doing another set of simulations to discuss the results with the team and possibly further optimize the speaker cabinet design.

 

[abdo123]

Rick just wants to make sure the speaker cabinet has the best radiation results with the simplest possible design.
... and I want a design as complex as possible to make a patent application feasible - just kidding!

So I'm doing another set of simulations to discuss the results with the team and possibly further optimize the speaker cabinet design.

Aah yes. The centuries old battle between the architect and the civil Engineer .

At the end of the day though people will judge (and make the decision to build) the speaker by how good it performs, not by how easy to make .

Thank you both for keeping us in the loop!

 

[Madjalapeno]

and I want a design as complex as possible to make a patent application feasible - just kidding!

Parallelogram, obround, ellipses, teardrop, trapezoid, crescent - so many choices to get Rick scratching his head. Must be so tempting.

 

[Rick Sykora]

Parallelogram, obround, ellipses, teardrop, trapezoid, crescent - so many choices to get Rick scratching his head. Must be so tempting.

Now you want me to get out my high school geometry books! Jees, sorry they did not survive the flood of the century.

Seriously though, in the last few sims, we learned some key things...

• top slots did not help as much as hoped (perhaps an understatement IMO)
• taller side slots helped considerably
• fewer bigger slots were not the panacea I was hoping they might be

@TimVG and @ctrl may have some details to add/correct my takeaways. Am sure @ctrl will! Anyway, it is a team effort, and we are learning as we go. As for my influence, will generally not sacrifice performance for simplicity. However, one goal is to have r2 be less expensive and cabinet simplicity helps!

 

[Madjalapeno]

Now you want me to get out my high school geometry books! Jees, sorry they did not survive the flood of the century.

Seriously though. in the last few sims, we learned some key things...

• top slots did not help as much as hoped (perhaps an understatement IMO)
• taller side slots helped considerably
• fewer bigger slots were not the panacea I was hoping they might be

@TimVG and @ctrl may have some details to add/correct my takeaways. Am sure @ctrl will! Anyway, it is a team effort, and we are learning as we go. As for my influence, will generally not sacrifice performance for simplicity. However, one goal is to have r2 be less expensive and cabinet simplicity helps!

If you want something drawing up in CAD to use as a template I'm more than happy to help. Laser cut acrylic makes a great router template, and I can factor in offsets for you.

For rectangles I made an adjustable template from some aluminum extrusion which works great.

 

[Rick Sykora]

Planning to do routing tomorrow. It will be above 40 degrees F in my garage so do not have to try to route with dust collection attached!

The back is already cut except for the Speakon connector.

 

[Rick Sykora]

Missed my last routing opp, but some warmer weather expected in the middle of the week. So turned to rest of cabinetry so am ready to glue once the front baffle is cut….

Here is dry fit. No fancy sides or side slots as yet. The cabinet is really quite small and was not obvious until I built it. All of it has been made from scrap MDF as you might guess by the different shades of the pieces.