ATH4 waveguide inspired multi way

[limacon]

Made some plates so I can align the mdf into the mould with two dowel pins.

 

[limacon]

While I’ve been waiting for things to cure I have just glued together a tool so that I can cast the rear cabinet shell in resin.

Ultimately to be covered with a veneer.

Hope to finish this tool later in the week.

 

[limacon]

constrained layer bonding!

 

[Patrick Bateman]

I do wonder though… with know-how of, and access to, such manufacturing technologies, why bother with wood at all, especially as good quality ply has become quite expensive.

Earl Geddes used PU (sheets and cast), Magico uses reinforced carbon fibre plus CNC’ed aluminium baffles in their M-series, and YG simply makes everything out of aluminium for their higher end speakers. I haven’t heard Earl Geddes’ speakers, but the other two makers achieved a clarity in sound I have never heard from any speaker with a wood cabinet.

Summas were my reference for half a decade. Although everyone knows Geddes for his waveguides, I think the cabinet on the Summas is what really stood out to me. I don't think I've ever heard a speaker that large than can "disappear." You turn off the lights and it sounds like you're listening to a much much smaller speaker.

 

[limacon]

For the back “U” shell I will laminate 1 ply glass on each face then cast about 10kg resin in the space between.
Maybe with some extra 75um bronze filler powder.

Then bond that giant “U” shape composite to the baffle frame below.

Then finish in a veneer and sand/polish.

 

[limacon]

Still aiming for something like



but can easily change the gel coat and veneer 🙂

 

[limacon]

One glass reinforced PU back shell.

 

[lenta]

Would like to see more pictures of the process. What is PU casting?

 

[limacon]

Something like

 

[limacon]

v2 waveguide + cabinet + HF10AK

REW -->Motu M3 --> MC2 T4-250 --> UMIK1 --> REW


0 to 45 degree, 1/6th smoothing, no EQ

Approx 22.5 degree, 1/6th smoothing, no EQ

 

[von Ah]

Wow, that looks fabulous to my untrained eye. Nice work!

 

[IamJF]

v2 waveguide + cabinet + HF10AK

REW -->Motu M3 --> MC2 T4-250 --> UMIK1 --> REW


0 to 45 degree, 1/6th smoothing, no EQ

View attachment 1223192

Looks good!
Can you show us this measurement with less smoothing (1/24 max) and a scale from 40-100dBSpl? 0dBSpl doesn't make sense in most rooms 😉

 

[TNT]

Yes - 50 dB on y-axis is "standard" 😉

//

 

[limacon]

Appologies! Some years in the making and not so much used REW for a while.

on axis 1/24th

approx 22.5 degree, 1/24th

approx 33.75 degree, 1/24th

 

[limacon]

Will remeasure with speaker a bit further off the ground and UMIK1 at 1m from baffle / 96db / ear protection!

 

[TNT]

First 2 is 60, last 50 ;-)

Looking good!!

Now, hit the distortion tab...

//

 

[markbakk]

Could it be you have early reflections in your measurements? Maybe the microphone stand?

Very impressive project btw. Cheers!

 

[sheeple]

Would be surprising if not. There should be something the size of some furniture still in the response.

 

[limacon]

now placed mic 1m , on a stand

 

[newvirus2008]

If you put the mic on an extension tube (e.g. pvc pipe) so that it 'reaches out' to the measuring position from farther away, the sound would strike the mic before hitting anything else (holder / stand), thereby allowing you to 'window out' any reflections.