Speaker Design…Waveguide, lets start from scratch……

20 cm x 20 cm x 25.3 cm = 10,120 cm3 = which is 10.12 Liters ..roughly a 22cm cube

Ok, Designing  a conventional enclosure would get us a volume of a less

Looking at this website – http://www.bcae1.com/spboxad2.htm

and plumbing in a few numbers gets us a volume of 6.357 Liters for a ported enclosure

Working backwards, that 6.357 liters gets us dimensions of 15 w x 15 w x 28.5 d (ish), or alternatley a roughly a 19cm cube……a 3cm per side reduction……

 

So, lets see just how small we could get ‘sensibly’ –

The speaker outside physical diameter is 98.2mm – lets call it 10cm. That’s going to drive the outer dimensions of the speaker…….

The speaker ‘cutout’ is 76.8mm – lets call that 80mm

I’ll use walls of 1.5cm thickness for rigidity (may change this later)

Speaker diameter = 6cm – that’s a surface area of 28cm2

One dimension of our rectangular waveguide is 8cm. lets call that width

8cm width x ? cm Height = 28cm2

28/8 = height =

That gives us waveguide of  8cm x 3.5cm……..

Working with the above gives us the following minimal enclosure dimensions……

2D folded start from scratch 1

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Speaker enclosures……A rabbit hole…

Blimey, who’d have thought……

Back in the old days, it was as simple as ‘buy a speaker’ , shove it in a box and voila…….

 

Nowadays though…………

http://audiojudgement.com/types-of-enclosures-which-is-the-best/

There’s quite a few, including the following types…………

  • Sealed enclosure
  • Infinite baffle
  • Open Baffle
  • Free-air
  • Bass reflex
  • Ported
  • Vented
  • Bandpass
  • Transmission Line
  • Folded Horn
  • Isobaric

Each has different properties, suited for different things……some are as easy as ‘shove it in a box’, others need complex enclosure geometry and some math………

Now, considering I have 5 speaker drivers waiting to be hooked up, own two 3D printers (and a CNC), Know a bit about Fusion360 and have a penchant for overthinking and overcomplicating stuff (hey, where’s the fun when it’s simple!?)…..I figured, lets learn a little bit about speaker enclosure design……

Turns out, there’s quite a few youtube videos……….

One in particular from a channel that I’d already subscribed to a few months ago…….HexiBase – Can a 3D printed enclosure Get low

Look at the size of that box!……..It uses a Folded Waveguide type resonance chamber for the enclosure…..which appears very similar in design to a ‘Transmission line’ style of speaker.

….Challenge accepted….I’m going to build a small Transmission line speaker!

3D Printed Speaker enclosures – another rabbit hole

PS95-8After months (and months) I’ve finally been able to pull my thumb out and start a long wanted upgrade of my somewhat old Home Theater system…….With a 3D printed ‘twist’

Continue reading “3D Printed Speaker enclosures – another rabbit hole”