Systems List › DIY › PSI 18" 13AV2 Re-cone
The response shape of this system has a notable peak centered at 42Hz that rolls off rapidly in either direction. The response is down 11dB by 100Hz and 14dB by 200Hz. The system sensitivity comes in at about 92dB at 42Hz but is only about 82dB at 100Hz and less than 81dB by 200Hz.
The sensitivity at 20Hz is a little over 76dB. Overall it is rather low. The group delay and waterfall decay indicate that there is some delayed energy decay near 42Hz as well which comes close to 1 cycle of delay. Still this is probably inaudible and not of concern.
The long term output compression graphs show that this system exhibits good output tracking with less than 1dB compression during the 105dB sweep and less than 3dB during the 115dB nominal sweep level. During the 120dB sweep level the amount of output compression increased dramatically to about 5dB in a couple of spots and the driver exhibited mechanical excursion noise and distortion indicating that the driver was clearly out of gas at that point.
The distortion results show a solid performance above 25Hz up through the 115dB sweep with less than 10% THD over the majority of the range. During the 120dB sweep the distortion is still held below 15% over that range. The deep bass distortion below 20Hz however exhibits elevated levels even at modest drive levels. Looking at the component make-up of the distortion shows that it is primarily the 3rd harmonic except for the octave from 25-50Hz where it is dominated by H2.
Maximum output burst testing shows the system to have large amounts of peak output across the 10-125Hz bandwidth for a system of this size but the distortion at 20Hz and below is elevated. In order to pass the CEA-2010 distortion thresholds in the deep bass range the output must be lowered dramatically by 4-12dB to keep H3 down low enough. A passing 10Hz result could not be captured.