DAPOLITO (MTM) Speaker with Waveguide and Harwood AMT 25

Hello, here i would present and discuss my new Speaker Design stepp by stepp.

At the End i will use aktive Elektronic for Crosover.

But also the Use of an passiv Crossover i will show you.

My first Step is already done.

The Design off an Waveguide for my Harwood AMT25.

https://www.diyaudio.com/community/...-cnc-3d-printing.318190/page-127#post-8023326

For the Midrange Speaker i will Use 2x Scanspeak 18W8434G00 Parallel.

I used the AMT 25 already in an 2 Way Box with an 18W4434G00 (Aktiv Time alligned) and this worked already very well.

For an MTM Kombination i need an deeper Crossover Point so i decided to build the Waveguide for an Crossover Point Between 1800 and 2000 kHz.

Next Step was to find Out how an MTM Measurement looks like Vertical and Horizontal.

For the first Approach i used my build 2 Way Speaker and put them together:

1749398133208.png


The Distance between the Middriver here is around 261mm Center to Center

Vertical i Measures This Way:

1749398295569.png


And here how it looks (Red line Microphone @ Point A, Green @ Point B):

1749398359120.png



Here the same Measurement with an greater Distance between the Middriver:

1749398502391.png


And the Measurments (Red line Microphone @ Point A, violet @ Point B):

1749398561749.png


Verticaly it is bettter to have the Driver Close togther, spcialy for an Corsoverpoint of 1800 to 2000Hz! I would say.
On the other Hand on a DAPOLITO Box you realy need to have youre ears @ the hight of the Tweeter for best listenning expiriences.
If you can sit, let say 3-5M away from the Box thats is less Important i guess.
But my listinig Position is in between 2,5 to 3M so i need to have the Hight of the Tweeter @ around 80cm from the Ground.

How i measured it Horizonta (Distance MTM 384mm Center to Center for worsed case scenario):

1749399579897.png


Here you cac see the Horizontal Measurings magenta 0degree, red 25degree and black 40degree:

1749399610900.png


So i would say Horizotal i could easy use an 2 kHz Crossoverpoint, Verticaly its more difficulty.
 
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My Design aproach goes this direction:

1749400327642.png



How wide the Window off that Waveguide would be on the Middriver i need to check. thats only an guess on the Picture!

I will 3D Print that shape off that Waveguide and test it on one Middriver for first Aproach.

The Distnaces between this Middriver on that Picture:

1749400663241.png


Not to Far i would say 😉
 
When did you buy these AMTs? The last pair of AC AMT2560s I bought made (another) change to the diaphragm and is no longer usable to me. These Harwoods look like the previous AMT2560 frequency response.
This New AM25 i bought last Year (24.04.2024) @ Hifisound.de also 4 new Diapragma for my oldest one (more than 15 years old, my first two, also two for spare 😉 ???)

https://www.hifisound.de/de/Lautspr...d-Acoustics-AM-25-Air-Motion-Transformer.html

https://www.hifisound.de/de/Lautspr...arwood-Acoustics-Ersatzmembran-AMT-AM-25.html

I am very obsessed with this Driver you clould say LOL
 
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If you measure the vertical at 30 degrees or more, it will have large nulls that are lower in frequency. I used to think that was actually an advantage as ceiling reflections would be reduced.
Yes i know but my Ears dont sit there😉 and did this Measuring to check how good my Mid Driver would work between the Center for Waveguide integration!

Also the AMT will not show an good Measuring @ 30 degree Vertikaly i guess.

I will do this Measurings also soon with AMT 25 and Waveguide 😉

I also hope that i get this Advantage because i have Wood on the Room ceilin and on the Graound of my Listening Room and this is realy bad!
I realy need some stuff like this for the Room ceiling:

https://www.amazon.de/dp/B07BD1QJB4...ments&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw&th=1
 
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By the Way, my second Waveguide is done and i did last Afternon a lot off Listening with this Crossover and i was realy blown away how good it is.

Used my Old DENON POA800 and it was already not that bad.

I need to reinstall all my CamillaDSP stuff, so no aktive listening for now, did the mistaker to update the Raspberry to last UBUNTU and now my both Aplication (CamillaDSP and Squeezelight wont work 🙁 ) Need to go into it again LOL

So i could use my HYPEX NCP Amps with MOTU Ultralight MK5

1749404609297.png


Subwoover wasn't aktiv while Listening!

My Brother in Law was listening to day and he was also blown away, how open it was also much Room and fast Timing on Percusions and Drums.
And never aggressive or Cold!