How to cut these fancy round shapes for boxes?

[moh.vze.com]

Hey guys, I was looking the box design prints for my sub woofer box that was built by Cody Johnson  a while back and there were some parts in the design I'm not sure how he did and was wondering if someone on here can explain what tools were used to make it happen.

In the image below, how do you make those round "R 3/4" " cuts? Also, how do you do that triangle looking thing in the middle for better air flow?

 

How do you make the "3/8" roundover on port opening?

Overall, it was a pretty sturdy built box and I hope I can build something at this high level design on my own one day. I think he charged me like $150 + $75 [Total $225] shipping for this box which seem like a decent price (except the shipping part).

As far as the box design goes, are all of these fancy round offs and what not necessary for air flow?  I think I paid a guy named Jason Summers like $25 just for the design based on my available trunk space. The hard sketch file can be found here:

http://vietpho.net/~images/2012carproject/jason_summres_box_design_25_dollars/'

P.S. I requested double baffle in the rear of the box design so I could mount my amp to it.

 

[moh.vze.com]

I was re-reading one of my old E-Mails from 2012 with my questions about box designs and came across this and thought I'd share:

Quote

Well, I will tell you a few things here that may help. This is general information so easy to understand. Bracing, first of all, cannot be underestimated. The best bracing is where the greatest area is in the box without any walls around. This can normally be between subs, or if single sub generally around the sub opposite of the port side (because the port essentially helps with bracing). Think flex, as you do now, and you can easily know where bracing will be best. Wherever the most open area is, is where the flex will occur the most. Double baffle is ok, but bracing can be priority over that. Both is exceptional. But this does not make a good box by itself. Many of the most common factors in a good box design rely in the build process- HOW WELL it was actually constructed and with what materials. The design part can make or break a superb build though, so it is one of the most important factors in a good or great box physically and acoustically. Flex is not a bad thing for boxes as long as it is under control and you are looking for musical output.....but if you can see the flex, rather than feel it, that is usually not a good thing. If you feel it, which most will first, then that means the resonances in the box are not constant and therefore peaks will be less noticeable and the output smooths out a bit. But again, the box design should control most of this anyhow by many other difference points of interest, such as using the golden ratio, and keeping time delay down, tuning for dips in the vehicle, etc. So all of this contributes to the overall QUALITY of the box. In your specific case, without me knowing the many details involved, your issue is mostly physical. SO, double walled, double baffle, and bracing as well as proper sized 45s in all corners will generally give you no issues that one can point out that obviously in any design when is done right. Hope that helps!

 

[Jahlg64]

A router with different sized roundover bits will give you the correct radius on those cuts. And the pieces in the port area can be cut on a table saw with the blade tilted to 45 degrees or whatever angle you may need. Simple construction tools.