3way concept M-T-W or T-M-W arrangement (D'Appolito)

[F Jell]

Hi all,
Following chassis:
T: Mundorf AMT25CS2.1-R
M: SEAS W18NX003 - Plan: 10 liter closed
W: SEAS L26ROY - Plan 80 liters +2xPM SL26R(XM003) + 100g each

Recently I had the chance to hear a 2-way arrangement - AMT + woofer/mid chassis.
For me it seems the the AMT is taking over the stage. As I like to build an old style "mid-bass" stage column speaker, I'm thinking about having the MID SEAS above the AMT (right arrangement) and not -as often seen- having the AMT on top (left arrangement)

May you share your thoughts about the different arrangements M-T-W / T-M-W. Offcause the T should be on "ear height" at both arrangements.

Someone told me that MID on TOP (right arrangement) gives the best harmony in such a trio, like "KEF" does or did in the past.
So the AMT might get a little bit into the background of the stage, like D'Appolito sound maybe.

That´s all for now, thanks everybody!

 

[Slick Minkus]

I'll throw my two-cents in before this gets moved to the DIY section...
They're all nice drivers but bad matches...

The 6" W18NX003 will never match the AMT25CS2.1-R directivity (well).
You will need a 2"-3" mid to create a good match with the directivity of a Mundorf AMT (maybe a 4" at a stretch).
This will also allow you to cross over above the precious 1-3kHz range.
Philharmonic use BMR drivers to achieve this, others use soft dome mids... I recommend looking at the Morel EM 1308.

The other issue you have is the arrangement...
The way to achieve a D'Appolito 'sound', is a D'Appolito arrangement (M-T-M).
M-T-W would be my preference for the non-D'Appolito choices you've presented.
But I wouldn't be confident in that choice without simulating each of the drivers directivity, baffle influence, and consequential effects on the floor and ceiling reflections.

 

[F Jell]

Thanks a lot.
Here the Mundorf (green)-Audaphon AMT-1i- is used. Crossover 1,8kHz
purple is a Seas Excel W18EX001

Lautsprechershop Little King

Auch, wenn die Box „Little King“ heißt: So wirklich klein ist sie nicht, zumindest nicht absolut gesehen. Aber angesichts der eingebauten Technik kann man sie dann doch als ziemlich kompakt bezeichnen.

www.hifitest.de

Little King

Kompaktlautsprecher,Little King,geschlossene Box,Lautsprecher,Bausatz,Audaphon AMT-1i(au-amt-1-rund), Seas Excel W18EX001(seas-E0017-08S), Wavecor SW280WA01(wc-sw280wa01-01)

www.lautsprechershop.de

Do you think the Mundorf AMT25CS2.1-R is such a bad choice instead of the Audaphon AMT-1i.
Whats about an other Mundorf AMTU110W1.1-R. This one maybe coupled even at 1.5kHz
Thanks for your reply.

 

[TurtlePaul]

I think that the point is that crossing a very wide tweeter with a 7” driver at 2khz makes for large directivity error. Any 7” woofer will barrow dispersion at 2khz. It is a tradeoff that 2-ways must make, but in a 3-way you can choose a midrange with much wider dispersion up to 3 khz+ (something with 2.5-4” diameter). You dont need that mid to have low distortion below 100 hz or low Fs.

 

[F Jell]

Hi all, thank you for your outstanding responses.

@TurtlePaul yeah your perfectly right it is more a 2way concept than a 3way concept.
The reason I like to take the 6'' W18NX003 and not a smaller one is - I like to play down to 80, 90Hz (lets see) how low the active crossover (minidsp) for the 6'' works good to get a very "dry" but "articulated" bass from one speaker.
The new W18NX003 seems good to handle up to 3kHz (so crossover at 1,8kHz might ok)

Seas Excel 6" W18NX003 (E0096-08) midwoofer review | HiFiCompass

What is on the test bench? Today our guest is again of the Scandinavian family - one of the oldest and legendary currently existing manufacturers of speaker drivers, the Norwegian company SEAS (abbreviation for Scandinavian Electro Acoustic Systems). The company's historical contribution to the...

hificompass.com

Alternatively, I could go for a satellite and an external woofer with the 10'' L26ROY. But my idea is to get them together in a column speaker close to each other to let them play together (crossover 10'' L26ROY runs a little bit higher to 100, 120Hz) to smash the "kick"bass (feels me about 80to120Hz) "articulated", "punchy" and "fat" from the same "direct" direction, if at such wavelength a direction can be said at all. Have you ever heard about such concept (off cause perfect phase alignment has to be done by the dsp). I'm not looking for a perfect linearity.

@Jim Taylor your perfectly right M-T-W has nothing to do with D'Appolito arrangement, a M is missing. My thoughts abut M-T-W is more to enclose the AMT to have all played together better. I had the chance to her such AMT and 10"" midwoofer and my feeling was an over-present "AMT sound". So I'm thinking about a M-T-W to lower a present of the AMT, I'm experimenting about.

Thanks for your thoughts.

 

[TurtlePaul]

But my idea is to get them together in a column speaker close to each other to let them play together (crossover 10'' L26ROY runs a little bit higher to 100, 120Hz) to smash the "kick"bass (feels me about 80to120Hz) "articulated", "punchy" and "fat" from the same "direct" direction, if at such wavelength a direction can be said at all. Have you ever heard about such concept (off cause perfect phase alignment has to be done by the dsp). I'm not looking for a perfect linearity.

I would save money while also getting better mids by using M15CH-002 as the midrange. Crossover to L26ROY at 250-300 hz - where ever the baffle step frequency ends up in your cabs. That is a 5”, so it should be much happier crossing at ~2.2 khz to the AMT.

 

[F Jell]

@TurtlePaul, yes perfect this has been the direction I came from
RAUMA 2 x M15CH-002 - D'Appolito
AMT in the middle crossover - 2,1kHz

Rauma

Standlautsprecher,Rauma,Bassreflexbox,Lautsprecher,Bausatz,Audaphon AMT 1i(au-amt-1), SEAS Excel W15CH001(seas-E0037-08S)

www.lautsprechershop.de

But I have now the 2xW18NX003 already in hand - maybe using them, when it doesn't work - I use them for 2 way bass reflex 18l.

Would you go for D'Appolito of 2xM15CH-002 / 2xM15CH-001 or just recommend 1x of them?
M15CH-001 has a really low sound pressure (85 dB) - so 3db more with D'Appolito should be a must.

Thanks a lot for your thoughts.

 

[F Jell]

to continue
I finished a prototype (took a old chest..) so see how the speakers sound together in that placement discussed above.
From my point of view it sounds great, never had such clear voices and fat bass together in such harmony - but maybe just luck. Also 1xL26roy (front) and the 2 PM (side) sound great in 80l. Also the SEAS W18NX003 (top: 120 to 1800 Hz) plays great with the Audaphon amt-1i (top middle) and let the amt-1i not play in the "for-ground".

Here a picture of demo cases for sound test. The front is not ready to correct radiation/baffle step etc..
A measurement will follow asap.
At the end there will be 1 case for all speakers.