3D Hexagonal Dimple Hifi Speakers | CNC Front Baffle

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Introduction: 3D Hexagonal Dimple Hifi Speakers | CNC Front Baffle

About: Designer, Maker, CNC Enthusiast, Audio Lover

I recently came across these wood textures on Pinterest and they peaked my interest into making some sort of 3D textured speaker build. I had also just set up my new Shapeoko 3 XXL so was looking for an excuse to make something with it.

So the scene was set, I set out to come up with a design for a solid wood speaker baffle that I could carve on my upgraded Shapeoko cnc machine.

Of the 4 textures, the honeycomb is my favourite and so this is what I set out to try and carve! Next step: figuring out how to cad and cam this up to get it made on the cnc.

If you enjoy this Instructable please do check out some of my other builds either here on Instructable or on my Instagram! I also upload some of the things I make to my Etsy so please do take a look! And please vote for this build in the audio contest! Thank you :)

Supplies

Hardwood for baffles

MDF for cabinets

Saw

Glue

CNC Router for the textured surface

Binding posts

Bass ports

Step 1: CAD

To form the pattern of heaxgonal dimples, I first had to figure out the best approach for forming them in Fusion 360. I started out, naturally, with a close packed grid of 4 hexagons and off set a plane below them. On this plane, which was 4mm below the surface of the wood, I added a point in the middle of the hexagons. A loft function could then be used with smooth transitions to form the dimple shape, simple really!

Next, I used a rectangular pattern function to cover the entire surface of the baffle with the dimples. I had already dimensioned the baffles based on some calculations done in WinISD but I won''t go into too much detail on that for this build i'm afraid!

A cutout was made for the actual speaker driver and I revolved a chamfer around the speaker cut out as shown in the photos. Normally I would add some features to the backside of the baffle to make the speaker driver sit better against the baffle but I didn't feel it necessary from past experience with these drivers.

Lastly, using the baffle and the calculations for optimum volume I added the cabinet to visualize how the speaker would look when finished.

Step 2: CAM

The next step in Fusion 360 was to generate tool paths for the front baffle. Because the machining of the chamfer around the speaker would be carried out by the final finishing pass, I decided to cut out the circle for the speaker first. Then, I would run the finishing tool path to machine the hexagon dimples and finally run a contour operation to bring the baffle to final size.

The finishing tool path was done with a 6mm ball mill and a 0.3mm stepover to reduce the need for sanding afterwards. Due to the small stepover, this tool path could be run fast at around 3000mm/min on my shapeoko 3 xxl. This resulted in a cutting time of 1h30m per front baffle.

I also generated some simple tool paths for the back panel to cutout holes for the binding posts and the bass port.

Step 3: Material Prep

Normally, I would chose white oak for the front baffle material. However, I wanted to try something a bit darker, more exotic and something I hadn't worked with before. I settled on wild mango which I was able to get from my local timber supplier. This wood is nice and dark with intriguing orange tints throughout the grain pattern. I had a hunch that the dimples should accentuate the colour when oil is applied. I cut two blanks with a bit of margin around the outside for the CNC router to machine away.

For the cabinets, I find it quicker to build them the traditional way now I have a track saw and mitre saw. The process is quicker and more simple than using the CNC. MDF is my material of choice as it is consistent, easy to work with and cheap. I ripped lengths of MDF to the correct widths to make the cabinet components with the track saw.

Step 4: Machining the Baffles

The mango boards were attached on the spoilboard with the masking tape and super glue technique; this gives access to all sides for machining and removes the need for clamps and tabs. With the cutout for the speaker finished, I loaded a 6mm ball mill and then started the long 3d machining tool path. Normally I would leave the machine to do it's thing but this was one of the longest things I had run on my CNC so I kept myself busy in the workshop to keep an eye on it!

Once this was completed, I ran the final contour tool path to finalise the dimensions of the front baffle. I then used a chisel to clean up the chamfer around the speaker cutout to smooth the transition where the machining met the pre-cutout speaker cutout.

Wit that all done, the last thing to do at this point was to do a light sanding on the dimples before finishing. A foam sanding pad makes this super easy as it conforms to the contours of the machined features very well.

Step 5: Making the Cabinets

These were just simple, mitered edge, mdf boxes. All mitres were cut on the mitre saw set at 45 degrees with an electronic level. These parts where then assembled with masking tape to hold the edges tight as the glue dried. When the glue dried I then added dowels to strengthen the joints and flush trimmed the dowels before finishing.

Step 6: Cabinet Finishing

The cabinets were sanded up to 400grit and then blown down with compressed air. I primed and painted the cabinets with satin wall paint, applied with a soft foam roller.

Step 7: Routing Slot for Back Panel

Admittedly, I should have done this before painting but I then routed the rabbet for the back panel. This was done with the appropriate router bit, set at a depth matched to the thickness of the back panel. I intended to use a piece of dense laminate flooring for the back panel as it is essentially pre-finished!

Step 8: Mounting Baffle to Cabinet

First, the speaker was attached to the baffle as it is easier to do so now rather than when the cabinet is glued in place. With the speaker secured with super glue and screws, I used dowels to create good alignment between the baffle and the cabinet to make the glue up more reliable and allow for easy clamping without the two parts sliding around and out of alignment.

I then used normal wood glue to attach the two parts and clamps all around to ensure a tight seal. Padding was used to prevent the clamps from marring the dimples or painted surface of the cabinet.

Step 9: Rear Panel

Using the same tape and super glue technique to hold the stock down to the spoilboard, the back panel was machined with its two cutouts for the bass port and the binding posts.

Step 10: Attaching the Panel and Wiring.

I soldered the speaker up and then installed the back panel with white silicon. The binding posts could then be soldered onto the speaker wire. Last of all, the speaker could be stuffed with polyester stuffing and then I installed the bass tube. These back panel fittings all had a bead of silicon around them to completely seal any gaps.

Step 11: Finished! + What I Would Do Differently

Last thing to do was to test out the sound and get some beauty shots!

I love the way that the textured baffles really emphasize the wood grain and colour, this was the main purpose of the build and I think this aspect turned out the best. The sound is decent with strong bass and a good mid range. Because the drivers are coaxial and fairly cheap, the highs are a bit sharp but these could be swapped out in the future as they are a standard size.

Although the cabinets are quite nice I would like to add the textured paint that I have added to my other builds as I am still a huge fan of this finishing technique but I can always do this in the future.

I am keen to try out some different 3D textures in some future projects and also experiment with different woods more to see how the grain pattern interacts with the 3D textures.

I hope you enjoyed this quick build and please do check out some of my other projects here on Instructables or on Instagram!

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Audio Challenge 2020

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    22 Comments

    0
    Gastonone
    Gastonone

    11 months ago

    I'm curious to know the acoustic efect. I know that for example a cloth over the baffle (front) of a speaker, gives more micro detail and less tiring high frequencies. So I'm curious what this pattern does.

    3
    jimvandamme
    jimvandamme

    Reply 11 months ago

    Sorry, I'm an engineer, not a poet. What do "micro detail" and "less tiring high frequencies" mean?

    0
    Gastonone
    Gastonone

    Reply 8 months ago

    Hi, sorry for my late reply. I didn't see yours.
    Micro detail, are the sounds that get lost in distortion or the normal details of the music, like the touch on instuments, background noises, the room the music was recorded in.
    Tiring high frequences. If you play (digital) music, there is a lot of high frequences travelling along in the signal (the music). This can cause it to be tiring to listen to music a longer time. You will probably not notice this since it is very common, but when you heard an audio system that took care of that, you will definitely notice the difference, being a more relaxing experience and a more musical and feeling that you can actually experience the preal person that is for example sining. Also the recording environment may be more 'visible'.
    It will take some training or experience to hear all this though.

    0
    Gastonone
    Gastonone

    Reply 10 months ago

    Micro detail is the finer details you can hear when you are listening to a higher end audio set. You can hear more nuances in the instruments and voice and maybe hear the venue the music was played in as well.
    Felt on the baffle, will absorb high frequencies that 'stick' to the front baffle and 'smear' the sound, masking it a tiuny bit harder to hear thise very fine details.
    Tiring hiogh frequencies is something that happens when you have too much high frequencies, or there is high frequency distortion (for example from 'jitter'). It gives an unnatural edge to the sound. You may not hear it at all, until you have listened to an audio set that does not have this and then you will know (and hear) what I mean. Music will be more realaxing, more involving, sounding more 'real'.
    A lot of people never heard 'analog' sound, but it is so much closer to experiencing the emotions put un the music than most digital music is capable of.

    0
    ssashton
    ssashton

    Reply 10 months ago

    People sometimes add felt or cloth around a speaker baffle to reduce diffraction effects, reporting clearer details in the sound.

    'Speaker baffle diffraction' is the key term.

    0
    Gastonone
    Gastonone

    Reply 10 months ago

    Hello,

    i have wrapped towels around my high end speakers and indeed experienced more detail. Thank you for your reply!

    2
    rodneykoch1969
    rodneykoch1969

    11 months ago on Introduction

    Speaker Enclosures !!!! 1 word totally changes the meaning. Great work on the Enclosures, Looks sharp! Voted!

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    hahaha

    2
    seamster
    seamster

    11 months ago

    What a gorgeous pattern, very striking results. Well done! : )

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    Thank you :)

    2
    AMbros Custom
    AMbros Custom

    11 months ago

    I have to say that buddy you did really fantastic work. Love that 3d honeycomb pattern. Great work.

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    Thank you!!

    1
    GTO3x2
    GTO3x2

    11 months ago

    No acoustic reason?

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    I did calcualtions in WinISD

    1
    LaurenR65
    LaurenR65

    11 months ago

    Love the honeycomb! I am a huge fan.

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    Thank you!

    1
    IdeaFactory
    IdeaFactory

    11 months ago

    Beautiful work indeed, from where to download hexagon file ?

    0
    Nickolae
    Nickolae

    Reply 11 months ago

    I will upload it here soon

    1
    Jaychouu
    Jaychouu

    11 months ago

    Cool, voted for you!