A circus-theater is a particular type of theater space. It is mainly characterized by the possibility of interchanging the typical configuration of theater, where the stage house is settled in quasi-circularly to the audience area, to a circus configuration, in which the stage is totally surrounded by the audience area. Despite the abundant literature that tries to objectively and subjectively assess the acoustic characteristics of several theater spaces, there is scarce information about the acoustics of circus-theaters. This work is a first approach to the acoustic characterization of such theater spaces. The main goal of this paper is to acoustically evaluate a circus-theater; for that, objective ``in-situ'' measurements have been carried out considering both stage configurations. ISO-3382 has been taken as the guidance to select the acoustic parameters to measure, together with some other well-known additional parameters of room acoustics. Measurements and characterization processes have been applied to the Circus-Theater of Albacete, as this is one of the few Spanish circus-theaters that still offers the possibility of using both stage configurations. Results allow to acoustically characterize a preliminary description of this kind of theater spaces, as well as comparatively study the theater and circus configurations from an acoustic point of view.
