Super horn loaded subwoofer with circular section development, characterized by extreme sensitivity, dynamics and emission power, made with an incredibly rigid and light structure in durable composite materials. Unlike all other alternatives currently available, this low frequency loudspeaker has been realized without technical and dimensional compromises, being fully developed both in terms of length and radiating surface. Thus it achieves maximum acoustic performance combined with an elegant design and personality, always keeping dynamics and control front and center. Nearly scratch proof surfaces and resistance to atmospheric agents combined with extremely high efficiency and world class sensitivity allow the Hydra to perform favorably compared with any product from the main competing brands. Hydra 8.1 guarantees the perfect loading of low frequencies in sensitivity, depth, control and SPL expressed by the usage of few watts. The most common subwoofers on the market (wooden box type) are horn loaded speakers with several internal turns, non-optimized sections and reduced length, leading to lower sensitivity, reflections that create distortions and ripples, and uneven loading. Therefore they need corrections by DSP with consequent mechanical stress caused by the excursion of the transducer, which creates more distortions while using the enormous amount of energy needed by the amplifier to obtain SPL. Hydra 8.1 uses a single hi-quality transducer of 18“(460mm). The structure is rigid, very light (considering the whole weight and the rate dB/Kg) The scenic impact is extraordinary and absolutely exclusive and unique on the professional sound market. The Hydra 7.1 ,vertical version, has a straight first part of the horn. Hydra 7.1 (vertical) and Hydra 8.1 (folded) have similar acoustic performance.