GETTING STARTED
Where to start.
Library, room drawn, loudspeakers placed, room described, then advice. That order and no other: it is the one in which the application refuses nothing — and in which the numbers mean something.
1. Fill the library
Always start here. You cannot place a loudspeaker that does not exist: with no model in the library, the plan has nothing to offer you.
Enter a loudspeaker
Library tab. Its name, its brand, its level at one metre on axis — the figure from the datasheet — and its coverage angle at −6 dB, **band by band**.
The catch — Coverage depends on frequency. A loudspeaker is very directional in the treble and nearly omnidirectional in the bass: a single figure would give bad advice, which is why the field is per band.
Import polar data
Rather than typing everything: export a text table from your viewer, angles in columns or in rows — both layouts are recognised. The −6 dB coverage is derived by interpolating between your readings.
The catch — Binary CLF files (.cf1, .cf2) are not read, and will not be. Their structure is not public: a reader that guessed would produce wrong directivity, hence wrong placements **with the confidence of right ones**.
2. Draw the room
A listening zone is an outline, an elevation and a rake. That is what replaces the "rectangular room" of simplistic tools.
Place a preset shape
Plan tab, Preset shape button. Rectangle, square, circle, half-circle, fan, horseshoe: you enter the dimensions, the shape lands at the centre and stays movable.
The catch — A rectangle drawn point by point with the mouse is not one: the sides are not parallel, the area is off by a few percent, and **all the reverberation inherits that approximation**. If your room is a simple shape, place it; do not draw it.
Raked seating and balconies
Each zone carries its elevation and its rake in percent. A balcony is a second zone, higher up. Ears rise with the floor.
The catch — The spread shown is that of **the whole room**, not the average of per-zone spreads. An even stalls area with a balcony 12 dB below is not a well-covered room, even if each zone taken alone is.
3. Place the loudspeakers
A placement is judged by eye and corrected by hand. The map recalculates with every move.
Place, aim, adjust
Click to place, drag to move. A second point sets the aim: that is what defines the axis. Then the trim height, the gain and the delay.
The catch — Seen from above, a box flown at 4 m aiming at the back looks exactly like one at 1 m aiming at its feet: it is the same arrow. **A downtilt is judged from the side** — open the section view.
Align the delays
Delays tab. Acustika computes what to apply so a fill arrives **after** the main system, localisation margin included.
The catch — The margin is not decorative: the ear localises whichever source arrives first. Without it the listener hears the fill and not the stage — precisely what a fill is meant to avoid.
4. Describe the room, not just empty space
The step everyone skips, and the one that changes results the most. Without it, the same map comes out for a church and for a treated studio.
Materials, height, audience
The room panel. Tick "account for the room", enter the ceiling height, the materials of floor, ceiling and walls, and the number of seated listeners.
The catch — The audience absorbs, and a lot: a full room can have twice the absorption of the same room empty. That is the main reason a soundcheck in an empty room does not match the show.
Read the critical distance
This is the most useful figure in the whole panel. Beyond it the reverberant field dominates the direct one: raising the level no longer improves intelligibility, you must bring a source closer or treat the room.
The catch — As soon as the room is accounted for, **the level spread becomes misleading**. The reverberant field is uniform: it flattens the spread. A room with 3.5 s reverberation shows a one-decibel spread — which looks like perfect coverage — with nearly the whole audience beyond the critical distance. Trust the share of the audience past the critical distance, not the spread.
5. Ask for advice, and know what it is worth
Acustika suggests a placement and explains why. That is what sets it apart — and it is also what needs reading most carefully.
Run the search
Look for a better placement button. The application tries several hundred heights, spacings and aims, and keeps the one whose calculated coverage is most even. It then says what each adjustment contributes on its own.
The catch — The advice reasons on the **direct field alone**, even when the room is described. This is deliberate: since the reverberant field flattens spreads, advice including it would prefer the cathedral to the studio, and look right doing so. What a placement controls is the direct field.
What the map does not prove
Acustika computes a direct field and a statistical diffuse field. It ignores individual reflections, diffusion and phase interaction between sources.
The catch — It cannot see a back-wall echo, which can destroy intelligibility without changing either RT60 or the critical distance. The STI shown is an estimate from the Peutz formula, not the impulse-response calculation EASE performs. The advice stays a proposal: the real room never matches the model, and no amount of decimal places fixes that.