First Proper Measurements · Oct 14, 2025

Finally got to first attempts on measuring — with plenty of good results, as you will see on the captures. About the method: I used two of them. First, just to put the box on the ground and measure a kind of "side view" on the floor.

Method 1 — box on the ground — Fig. 01
This way we get very near to anechoic measurements: the system is rotated, the mic is placed at 15 metres, same height, without reflective surfaces.

We also measured at normal hearing height — about 5 feet.

Fig. 03
Setup overview. Trees around, no reflective surfaces, the honest air of Temuco.

The focal approach — −35° off axis.

Started with a directional approach — the focal approach.

The focal algorithm in the Danley 2D tool — Fig. 04
By the way — this is the official research tool for Danley, 2D this time. We were pointing at −35° off axis.

Measurement geometry — Fig. 05
So in our way of measuring, we would be standing here — a direct line to the beam.

Narrow-band 18 dB attenuation — Fig. 06
Measurement result — a very narrow band, but going to **18 dB of attenuation**.

On the drivers. These particular ones are quite directional and super mid-centered. Bass and highs were directional on their own. The mismatch of the individual driver's polar balloon was noticeable — but the method is perfectly explained.

On 4 kHz and 250 Hz, theoretically we still have difference at 35°, but due to the directional drivers, the polar balloon was noticeable and kept us from fully appreciating the thing. We measured the polar balloon of a single driver, and it was nasty. But — look what we got at the sweet-spot frequencies.

Sweet-spot frequencies, yellow vs green — Fig. 07
Yellow is −35°, green is 0°. It was a very sweet sensation when the sound was filtered to the sweetest frequencies — to walk around and find yourself losing the M-NOISE as you approached 0°.

For me, the subjective experience of sound always becomes more and more important. What we measure, versus what we hear.

— on the walk toward axis

Mid-hi range — natural response.

We measured the mid-hi range spectrum with the system in no-algorithm mode — the natural response. On the Danley simulator we see this:

Natural response simulation — Fig. 08
Simulation — natural response of the 8 × 4" line.

Natural response measurement — Fig. 09
Measurement — natural response from the field.

0° vs 35° comparison — Fig. 10
0° vs 35°. The system remained omni up to 1.6 kHz — after that, directional. As expected, and even more due to the directionality of these drivers.

I was thinking on sending some images to Alison to do CAD, preparing a means for you guys to have a unit there to test — specially Tom. (We will also talk about the end-fired cannon.)

Drivers fixation sketch — Fig. 11
I bet you got the idea with those small triangles for the driver fixation.

Pointing the drivers to the sky.

At one moment I wanted to hear only the acoustical summation of the sources — and not the inner polar pattern. So I started to measure like this.

Drivers pointing to the sky — setup — Fig. 12
Drivers pointing to the sky. Keeping the mic at low height gives us a much more "omnidirectional" response to study the interactions.

Off-axis, angular distance preserved — Fig. 13
Important — to be off-axis, and to maintain the angular distance.

With the idea of pointing to the sky, end-fired also became much, much easier to do.

— the method generalises

End-fired, easier from the sky orientation — Fig. 14
End-fired, much easier from this orientation.

We also noticed that the best "sound" response was with a convex array — "opening the coverage".

So now I have the unit in my hands with the Marani processor, so I hope this week to do massive measurements — specially end-fired, just curious.

See ya around.
— Sebastián, 10-14-25.

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Pointing to the sky. The drivers look up. The mic, off-axis, hears omni.

Finally, first attempts on measuring.

The focal approach — −35° off axis.

Mid-hi range — natural response.

Pointing the drivers to the sky.