05. March 2013 XL2 Firmware V2.53 The firmware V2.53 extends the XL2 with the following features: The sound level meter includes a 4.4 Hz high pass filter for wideband measurements, thus the result correlates with the sum of the RTA values. Various bug fixes improve the STIPA and SLMeter functions Download the new firmware at http://my.nti-audio.com. Categories: Archive Tags: