3D printing loudspeakers - RD Physics FR1 and FR2 

Agreed. A single-driver point source can sound very natural with light program, but seem overwhelmed with complex music. We have moved towards coaxial drivers for rock and metal music.

For subwoofers, it could be enough to increase the resonance frequency outside the passband by stiffening the structure. For full-range applications increased areal mass will reduce the magnitude of the resonance ("mass law").

What printer do you have? This is fairly large for a resin printer. Have a look at our video about the SW1 subwoofer, where we filled the wall with epoxy and silicon carbide. We haven't tried sand yet, but it's definitely interesting and we will do that for a future subwoofer build.

@@DIYAudiobyRDPhysics I own a Anycubic Photon S and already made some tests. I sliced the model i several parts but already stopped with the front part. With the actual resin the result is too brittle and tighten screws is not possible without breaking the structure. Will reconsider to do it with wood filament on a PLA printer. Also not so time-consuming ;)

@@Chestnutspread The resin printer could be nice for horns, waveguides, grilles, vents and other smaller parts where smooth surface is nice to have and brittleness is not a problem

Combining carpentry and 3D printing is the best way to go about it. Make the bass enclosure simple, heavy and stiff from wood and then add a printed mid-tweet enclosure on top, which benefits more from the design freedom printing offers. I say go for it and let us know how it goes!

Achieving air tight and pressure resistant enclosures with 3D printing can be challenging mainly due to the inherent void content of extrusion processes and low Young's modulus of plastics. This does not mean that sealed enclosures are a bad idea. It just means that attention need to be paid to process parameters (number of wall lines, line overlap) and geometric stiffness (section modulus, spherical shape). 3D printed enclosures are typically small and small enclosures struggle to get large enough vent cross-section to avoid port noise while minimizing the amount of space the vent itself takes up. We've used passive resonators instead (SW2), but even with the SW2 we prefer a sealed configuration with large amounts of EQ. Also, a vent does not remove internal pressure at relevant frequencies, open baffle does. We have very interesting open baffle developments going on, so stay tuned!

We love Linkwitz's designs and are looking at controlling directivity, both low-frequency (cardioid) and high-frequency (waveguides) as well as some low-directivity drivers like BMRs.

@@DIYAudiobyRDPhysics dutch and Dutch 8c is doing cardioid in midrange than low freq

@@anandshah71 That is a very interesting loudspeaker indeed.

That's a strong statement :) The drivers you mention are all quite a bit more expensive than the MA drivers used here. On a higher budget we would recommend multiway speakers. We make sand-filled walls for subwoofers, but for small enclosures the wall thickness takes up a big chunk of the volume.

Hypex Fusion amp projects are coming and Purifi drivers are interesting.

Sand can be added after printing, too, and works well. Carbon fiber is kinda cool, though, right?

@@DIYAudiobyRDPhysics i like the carbon look and added stiffness. I mean adding the sand where the into the model to the infill before the top layers are printed