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Magico A5 spinorama (CEA2034)

Alice of Old Vincennes

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With FR sins of omission (dips, roll-offs) are much less objectionable to me. I think the signature is deliberate to make it inoffensive across a broad range of rooms, especially bad placement in a bad room (e.g. lots of glass, not unheard of with the clientele). And honestly, for 5-6k more than a Revel 328, I'll take this for fuzzy feelings of entering the big boy ultra-high-end club, the machined enclosure and US production.
My, my, sins of ommision. Pathetic.
 

ctrl

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Pretty sure the tweeter dropping above 7000Hz is an intentional thing that Magico...
This is how a true pistonic dome behaves. It's physics. If you see a 1" dome extend at full efficiency above10K, it mainly contained rubbish.

An ideal tweeter in infinite baffle, which may well be compared to the Magico's tweeter at frequencies above 7-10kHz (edge diffraction effects mainly take effect at lower frequencies - with the Magico rather around 2.5kHz), behaves as follows.
Simu sketch ideal tweeter on infinite baffle:
1624305153191.png
FR deg 0-90
1624303985830.png

An early drop of the axis frequency response from 7kHz is not a "natural" behavior.
This can be observed very impressively in the measurements of the Blisma diamond tweeter:
1624304473500.png
Source: HifiCompass


In addition, the tweeter of the Magico is in a waveguide and this controls the radiation pattern and the on-axis-FR:
1624304640469.png


The first small step of the waveguide around the surround of the tweeter significantly determines the radiation pattern at very high frequencies, but also the axial frequency response - of course the rest of the waveguide influences the radiation and the on-axis FR as well, but above 7kHz the first step has a decisive effect.
This step leads to an even increase of the frequencies from 3kHz.

Simu sketch with step:
1624305071381.png
tweeter with 3mm step FR deg0-90 on IB:
1624305266176.png


As @richard12511 said, the early frequency response drop of the Magico is thus clearly due to the crossover - for example, a resistor of a few ohms directly in signal path of the tweeter (depends on the impedance of the tweeter).
 
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BobR

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I can assure you, there is no such step on the tweeter faceplate, just like there is no "drop like a rock" response @7K.
 
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ctrl

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I can assure you, there is no such step on the tweeter faceplate, just like there is no "drop like a rock" response @7K
Then Magico should update their website, because that's where I got the image detail that shows a clear step to control and increase the top high frequency range, along with the entire waveguide.

1624382732462.png



A tweeter that works completely without any "directivity/sound control" (no step, waveguide,...) would be for example the Bliesma T34B-4 34mm:

1624383336887.png
 

ctrl

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It is not a step, it is (clearly) a radius.
In the sectional view of the tweeter, it looks like its step (with a slightly rounded edge). The step is usually 2-4mm and controls the radiation in the uppermost tweeter range and raises the frequency response on axis - as shown in the simulation.

1624384824769.png

The tweeter of the Magico series has a flat waveguide after the first step - which I do not show here.

If you have a picture that shows otherwise, bring it on - no one (especially me) wants to make false statements here in the thread.
 

Valentin R

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Then Magico should update their website, because that's where I got the image detail that shows a clear step to control and increase the top high frequency range, along with the entire waveguide.

View attachment 136939


A tweeter that works completely without any "directivity/sound control" (no step, waveguide,...) would be for example the Bliesma T34B-4 34mm:

View attachment 136941

It’s clearly a waveguide

Look at the 3 screws and the angled faceplate

And the. Spinoramas shows the results
It falls starting @ 7k

It is what it is
Some people like it some don’t. But it does not change the fact
 
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richard12511

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In the sectional view of the tweeter, it looks like its step (with a slightly rounded edge). The step is usually 2-4mm and controls the radiation in the uppermost tweeter range and raises the frequency response on axis - as shown in the simulation.

View attachment 136947
The tweeter of the Magico series has a flat waveguide after the first step - which I do not show here.

If you have a picture that shows otherwise, bring it on - no one (especially me) wants to make false statements here in the thread.

In the picture on their site, it's quite clear that it has such a step. Maybe that's an old photo that on their site?
 

ctrl

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In the picture on their site, it's quite clear that it has such a step. Maybe that's an old photo that on their site?
At least the step on the tweeter's front panel was still there when Stereophile wrote their review. The flat waveguide is difficult to see.

But I think it is clear that it is not a flat faceplate and thus the tweeter directivity is not purely determined by the dome and piston movement, as for example in the Bliesma tweeter shown above, but the directivity and thus also the axial frequency response is controlled by interference with the flat waveguide.

Glad we talked about it... ;)

1624394558508.png

Source: Stereophile.com
.
 

Beave

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Wow. $25k and they couldn't even make the speaker go up to 20khz. As usual, everyone is amazed at the "smooth directivity," seeming to forget that that frequency response is far more important.

But the top octave (10 to 20kHz) is probably the least important octave for frequency response errors.
 

BobR

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It actually goes up to 50K. Read the part about pistonic domes
1624410288639.png
 

richard12511

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It actually goes up to 50K. Read the part about pistonic domes
View attachment 137000

The measurements in the original post are much more accurate and detailed, though. I don't see why we should even need to look at measurements like this when we already have the best (most accurate) data.
 

preload

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Which octave would you consider less important? 10-20Hz? 20-30Hz?

I would think that 10-20kHz probably is one of the least important octaves. I believe that Geddes talks about how in his research people actually preferred some level of downward tilt above 8-10kHz or so.

Oh believe me it's important. But don't take my word for it - try adding a 1dB high shelf filter to 10khz-20khz. It makes a huge difference in voicing. In fact, I adjust in 0.5dB increments.

It's amazing the logical stretches people will make just to defend the beautiful directivity.
 
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preload

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Magico A5
1624410893222.png

Kef LSX
1624410755542.png

Yep, they look about the same to me, both rolling off like a mother in the top octave, and flat down to about 50Hz on the bottom octave.
Thank goodness for measurements. I know what the LSX sounds like, nice and rolled off. Can predict same for the Magico.
 

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