• Rasmus Bo Bertelsen
  • Tim Hede Stenholt Jensen
  • Andrea d'Onofrio
4. term, Acoustics and Audio Technology, Master (Master Programme)
Acoustic guitarists performing for medium to large audiences often need amplification of their guitar in order for the audience to be able to hear the performance. Unfortunately, this amplification is generally provided by traditional guitar amps/loudspeakers, which often results in a different spatial sound impression due to the different sound radiation pattern of the loudspeaker compared to the actual guitar.

This project aims to investigate methods for synthesizing the radiation pattern of an acoustic guitar with a compact loudspeaker array. Based on acoustic measurements of the radiation pattern of a guitar and numerical simulations of different loudspeaker arrays, a prototype with 20 loudspeakers is designed to specifically recreate this radiation pattern.

Methods for designing optimal FIR filters for recreating the directional magnitude response of the guitar are also investigated. These filters are implemented using both all 20 loudspeakers as well as 12 selected loudspeakers on the array.

The performance of the loudspeaker array is tested objectively by measurement of the loudspeaker array radiation pattern, which afterward is compared to the measured guitar radiation pattern. Results show that the loudspeaker array is able to synthesize the desired guitar radiation pattern very well up to around 2 kHz, but a rough approximation of the guitar radiation pattern is still seen at higher frequencies.

Using only 12 loudspeakers resulted in a slightly reduced performance in an objective sense, but the question of how similar a synthesized radiation pattern needs to be in order to perceptually recreate the spatial sound impression of a guitar remains to be fully revealed.
Publication date3 Jun 2021
Number of pages203
ID: 413532321