Systems ListDIY18-Sound 21LW1400 sealed

Measurement Details

AmplifierPowersoft Digam K10
Outside Temperature77 F
Date TestedMar 3, 2012
Settings & EqualizationNone...


Efficiency for this system is quite good with the response shape showing the usual sealed system roll off which in this case starts a little higher in frequency due to the powerfully motor’d 21LW1400 being very efficient. The F3 is near 70Hz.  The upper bass response is clean and extended. This system showed no issues in the time domain and a clean rapid decay of energy. Long term output compression testing showed excellent behavior until the 115dB nominal sweep level where compression of about 2dB was in evidence below 25Hz and above 90Hz. Also the driver started to complain a bit in the low bass region where excursion is high. During the 117dB nominal sweep the output was clearly heavily compressed reaching about 3dB in the 16Hz range and almost 4dB above 90Hz. Also the driver distorted heavily due to over excursion in the low bass during the sweep. Clearly the driver is out of gas at this point both from the standpoint of power handling and stroke. Looking at the THD generated during these sweeps it can be seen that the 110dB sweep the driver is still in control as the result is excellent with less than 5% THD above 30Hz and less than 17% all of the way down to 10Hz. During the 115 and 117dB sweeps the distortion jumps significantly indicating that the driver is past its point of linear excursion in the low bass and starting to show effects from heating in the top of the bass range.  Looking at the component make-up of the distortion shows that it is predominantly the 2nd harmonic at 45Hz and above and 3rd harmonic dominated below that point. CEA-2010 burst output testing shows this system to have prodigious peak headroom of over 125dB at 2 meters ground plane at 40Hz and above. This system still exhibits respectable output for a system of this size below 25Hz. Clearly the output is limited by distortion as the driver runs out of its modestly rated linear stroke, as ignoring the distortion thresholds it will produce about 3dB more peak output before damaging the driver mechanically starts to become a concern. 

Multi-Series Charts

Extended Charts

Comparable Charts

(Select an alternative system's measurement to compare to this one)


graph graph graph graph graph graph graph