Set-up method for array-type sound system

1. A set-up method for a surround sound loudspeaker system capable of generating at least one directed beam of audio sound, the surround sound loudspeaker system being in a room and comprising an array of electro-acoustic transducers, the room comprising a listening position, the method comprising:

emitting directional beams of set-up sound signals from the array of electro-acoustic transducers into the room;

registering at least one reflection of the emitted beams at one or more locations within the room; and

evaluating the registered reflections to obtain data for use in configuring the surround sound loudspeaker system.

2. The method of claim 1 , wherein each signal is emitted from a plurality of electro-acoustic transducers in the array so that the beam is emitted in a desired direction.

3. The method of claim 1 , wherein different signals are simultaneously emitted from different electro-acoustic transducers.

4. The method of claim 3 , wherein the different electro-acoustic transducers are located at one or both of an edge position and the centre of the transducer array.

5. The method of claim 3 , wherein the beams are emitted as spatially constrained beams of sound to a range of directions, the spatially constrained beams of sound being laterally constrained to form narrow vertical beams.

6. The method of claim 5 , wherein the spatially constrained beams of sound are laterally and vertically constrained to form narrow point or ellipsoidal beams.

7. The method of claim 1 , wherein the registering includes positioning at least one microphone in the room and recording the at least one of the reflections using the at least one microphone.

8. The method of claim 7 , wherein the at least one microphone comprises a plurality of microphones arranged in a known geometric configuration.

9. The method of claim 8 , wherein the known geometric configuration is a tetrahedral configuration.

10. The method of claim 7 , wherein the at least one microphone is physically positioned in or on the surround sound loudspeaker system.

11. The method of claim 7 , wherein the at least one microphone is positioned at or near the plane of the array of electro-acoustic transducers.

12. The method of claim 11 , wherein the at least one microphone is positioned at or near the centre of the array of electro-acoustic transducers.

13. The method of claim 1 , wherein the evaluating includes determining the listening position relative to a location of the surround sound loudspeaker system.

14. The method of claim 1 , wherein the evaluating includes identifying multiple acoustic paths to the listening position.

15. The method of claim 14 , wherein the evaluating further includes assigning different audio channels to different paths.

16. The method of claim 1 , wherein the evaluating includes identifying clusters of reflections in the registered reflections.

17. The method of claim 1 , further comprising using pre-known data relating to the geometry of the room to exclude beam directions.

18. The method of claim 17 , wherein the pre-known data are provided by a human operator, the method further including prompting for the input of the pre-known data.

19. The method of claim 17 , wherein the pre-known data are provided by a previous application of a set-up method.

20. The method of claim 1 , wherein the evaluating comprises recording the time elapsed between emitting the beams and receiving a first reflection at a location within the room.

21. The method of claim 1 , wherein the evaluating comprises determining the distance of surfaces from the surround sound loudspeaker system by scanning set-up sound beams around the room.

22. The method of claim 1 , wherein only a first predetermined portion of the registered reflections is evaluated in the evaluating.

23. The method of claim 1 , wherein the beams emitted from the array of electro-acoustic transducers are focused such that the focus point is near to an estimated reflection surface.

24. The method of claim 23 , further comprising using a feedback loop to provide that the beam focus tracks the estimated reflection surface position as the beam moves.

25. The method of claim 1 , wherein at least one of the registered reflections is multiplied by a phase shifted version of the emitted beam to which it corresponds so as to discriminate beams reflected by surfaces that lie a predetermined distance from the array of electro-acoustic transducers.

26. The method of claim 1 , wherein at least one of the beams emitted by the array of electro-acoustic transducers comprises a chirp signal.

27. The method of claim 26 , further comprising using a matched filter to decode a reflected chirp signal to improve signal to noise ratio whilst maintaining adequate range-resolution.

28. The method of claim 26 , wherein the chirp signal reduces in frequency during its duration.

29. The method of claim 1 , wherein the evaluating includes determining the angle of reflective surfaces relative to the array of electro-acoustic transducers by analysing time of receipt of a plurality of reflections, each representing a first reflection of a corresponding emitted beam.

30. The method of claim 1 , wherein the evaluating includes determining the angle of reflective surfaces relative to the array of electro-acoustic transducers by analysing relative amplitude of a plurality of reflections, each representing a first reflection of a corresponding emitted beam.

31. The method of claim 1 , wherein the evaluating comprises analysing a change in received first reflection signal amplitude and analysing a change in time of the first reflection signal amplitude to determine whether a reflecting surface is continuous, planar or curved.

32. The method of claim 1 , wherein the direction of beams emitted from the array of electro-acoustic transducers is set to track detected discontinuities between reflective surfaces in the room.

33. The method of claim 32 , wherein the direction of beams emitted by the array of electro-acoustic transducers is caused to veer to one side of an estimated discontinuity to confirm the presence of the discontinuity in the reflective surfaces.

34. The method of claim 1 , wherein the evaluating evaluates presence of a hole in a room surface in a particular direction when no reflected beam is registered following an emission of a beam from the array of electro-acoustic transducers and it is thereafter determined that audio sound beams are not directed towards the hole.

35. The method of claim 1 , wherein the surround sound loudspeaker system is for playback of surround sound channels.

36. The method of claim 1 , wherein the registered reflections are evaluated to determine directing parameters for use in directing a future beam of audio sound.

37. The method of claim 36 , wherein the emitted beams are also registered and evaluated to determine the directing parameters.

38. The method of claim 36 , further comprising:

using the directing parameters to direct the future beam of audio sound into a desired direction.

39. A surround sound system comprising:

an array of electro-acoustic transducers for emitting directional beams of set-up sound signals;

means for registering at least one reflection of the emitted beams at one or more locations within a room; and

means for evaluating the registered reflections to obtain data for use in configuring the surround sound system.

40. The system of claim 39 , wherein the means for evaluating comprises a signal processor that outputs time of first reflection of an emitted beam and/or amplitude of the reflection relative to the corresponding emitted beam.

41. The system of claim 39 , wherein the system is configured to firstly determine positions of the major reflecting surfaces in the room and thereafter to determine directions in which surround sound channels will be emitted.

42. The system of claim 39 , wherein the means for registering comprises at least one microphone.

43. The system of claim 42 , wherein the at least one microphone is positioned in the surround sound system close to the array of electro-acoustic output transducers.

44. A surround sound system for a room comprising:

an array of electro-acoustic transducers configured to emit directional beams of sound signals;

controller electronics configured to control the array of electro-acoustic transducers to emit directional beams of set-up sound signals in different directions; and

a detector configured to detect reflections of the set-up sound beams at one or more locations within the room,

wherein the controller electronics is further configured to generate, based at least in part on the detected reflections, surround sound system configuration data usable in steering directional beams for surround sound channels.

45. The surround sound system according to claim 44 , wherein the controller electronics is configured to generate the surround sound configuration data based on earliest reflections of the set-up sound beams.

46. The surround sound system according to claim 44 , further comprising:

a signal processor configured to determine time lapses between the emitting of set-up sound beams and the detecting of their respective earliest reflections by the detector, and amplitudes of the respective earliest reflections, and

wherein the controller electronics is further configured to determine room shape based on the determined time lapses and amplitudes and to generate the surround sound system configuration data based on the determined room shape.