Directiva r2 monitor prototype build

[RickS]

Well it has gone up to 50 F and that was warm enough to do my long overdue routing of the r2 front baffle!

Here is the pic…

 

[RickS]

The woofer backside gets 10 mm roundover to help airflow...

Cannot do much more without a special jig as outer recess leaves less material for router bit bearing to ride on.

 

[RickS]

Edit: for newcomers, jump ahead to post #31, unless you want to see me waste my time fixing a design error

Now we can start to glue it together. First attaching the bottom to the back…

If I can get base together and set overnight, tomorrow should be warm enough to do flush trim routing!

 

[RickS]

Next will add the angled side parts…

After doing the opposing side, I took some time to check fitment of the top. It is easier to trim the angle before gluing it on. Sure enough, it had some excess, so marked a line and trimmed on the table saw.

Using gravity and remembering that the I want a flat front surface, I sanded the three joint and glued against my table saw fence like so…

Am still working through the design for the sides with the vents. Since needed for flush trimming the front baffle edges, will tape something in place temporarily.

 

[RickS]

So while I cut side panels, I have not glued them as I want to create a removable one. While the initial prototype demonstrated promising results, not clear they are optimal and what else we might try. As you know, am also trying to optimize around making easy to build (and ofc good aesthetics).

I realized that may not be able to accomplish all the goals in a single iteration (but not looking to do an extensive experiment either!). Here is the latest pic…

As I ponder different possible designs, am reminded that I should consider how leaks and or structural resonances can also affect the speaker performance. So want something sturdy too. While I continue to cognate, will get in a round of flush trimming and roundovers to make some progress.

 

[RickS]

Flush trimmed and rounded over…

 

[Madjalapeno]

I can't get over how small it looks.

 

[RickS]

I can't get over how small it looks.

pretty much because it is pretty small..

Could add a ruler, but not much need as is a foot tall and about 7 inches at its widest.

For metric folks, about 30 cm x 18 cm

 

[RickS]

I have figured out a structure for interchangeable side panels. Decides to create a frame around the edge so, I can seat different 6 mm thick vent panels. As I went to build, realized I did not have any smaller pieces of 12 mm MDF to create the frame. So, I decide to cut some strips from 19 mm MDF. This created another problem as it would force the first vente to be further from front than desired. Since had some 6 mm MDF, cut some 12 mm strips from it and will use those along front side and top.

As I went to finish cutting, hear a familiar sound and knew (my old Craftsman) table saw pulley was slipping. I have cleaned up and disassembled but need to reassemble. Before I do, am going to buy some new thread locker and apply to the pulley set screw. Will get out first thing in morning, and then can finish trimming and glue it up. Pics forthcoming...

 

[RickS]

Those pics will have to wait a bit...

After I posted the last pics, @ctrl pointed out that the round overs did not look quite right. So, I revisited yesterday and, along with a height error with the back baffle, decided I would redo before adding a fancy framing for interchangeable sides. Behind the scenes, I had taken the design used by @TimVG and simplified so the cut angles and tolerances to make the build easier. In hindsight, went a bit overboard with adding some additional wiggle room. This was thought to have little impact on the overall design but did not really realize until almost completed the cabinet.

Anyway, think you will like what you see with the updates. I broke down the original cabinet and trimmed the front baffle down. Most of the other pieces needed to be recut and that was done yesterday. Still need to redo the back baffle.

Stay tuned!

 

[RickS]

Ok, starting over again with another design change for less side seams and ensuring any marginal ones end up on the (less visible) speaker bottom. Here am attaching the top to the back…

 

[RickS]

So, here is most recent pic from last night…

I did another dry fit and looks good but had altered the bottom for the new sides and decided to do another consult with @ctrl. It turns out my new design would be difficult to sim and so the prototyping would lose that benefit, so I have adjusted again and am now cutting new bottom and sides.

 

[RickS]

Another dry fit before I cut some more sides and some vents…

The main change is towards a slimmer width. The sims showed improvement too!

 

[abdo123]

Another dry fit before I cut some more sides and some vents…

View attachment 188664

The main change is towards a slimmer width. The sims showed improvement too!

Slimmer and better performance? My partner approves!

 

[RickS]

Am working through the side panels. I am planning a few at this point:

1. Solid ones so we have a baseline for comparison
2. A four slot one akin to what @TimVG with his proto
3. A large single slot one like is done for the D&D 8c

Can also do some variants by blocking portions of 2 or 3 to see if is better. Btw, the sim suggests that #2 is better than #3.

 

[abdo123]

Another dry fit before I cut some more sides and some vents…

View attachment 188664

The main change is towards a slimmer width. The sims showed improvement too!

Btw is it me or the drivers are not at the center of the baffle?

 

[RickS]

Btw is it me or the drivers are not at the center of the baffle?

Yes, they are centered quite well.

More likely you are seeing my poor picture taking and then trying to correct it afterwards on my iPad.

Also, you might be looking at router marks that are not final. The front baffle round over needs to be redone to fit the new cabinet.

 

[RickS]

Dry fit of a vented side panel…

Not as pretty as a set of routed vents, but a lot less dust and only needs table saw.

 

[RickS]

Since will need to measure soon, need to clear out our family room. Since early January, have had 2 of these sitting in there…

They are the end shelf units from a bigger entertainment unit from our living room. We recently repainted and decided it had to go. I had to cut the tops off to clear the ceiling. Today I trimmed the rough cuts and put the molding back on. They will be repurposed for our laundry room storage.

 

[RickS]

Now will complete some vented side panels. These are comparable to @timvg’s prototype except the vents are a bit taller. Using my table top and fence for alignment, am building the side starting at the top with front against the fence.

Placing the one of the front vent pieces along the fence and 10 mm drill bit for spacing another piece, I flip the top piece down and and put some glue on spots to mate with vent pieces.

Using the drill bit to space, I add glue to the other 3 pieces of the side panel and attach to the top….

Note I did cut the larger piece wider than needed but will trim it later. Next line the bottom piece up and prep with glue to attach to the upper assembly…

Flip down and attach to upper assembly. Working left to right, check spacing using drill bit or a 10 mm spacer…

At this point, I use a small paint brush and clean off the excess glue. Ensure the assembly is up against the fence and lightly clamp…

Check spacing one last time and let it set overnight.