Steel tube combination for use in subwoofers with flange adapter. The height is fixed with a safety hook and secured by a clamping screw for a vibration-free and firm fit. The slim design of the clamp allows space-saving transport and ensures a stylish appearance. The usable height is between 955 and 1,480 mm and is adjusted in 3 steps of 175 mm. A useful mounting aid also facilitates the installation of the speaker.