NTi XL2 + M4260 Acoustic Analyser & Sound Level Meter

NTi XL2 + M4260 acoustic analyser


The hand-held NTi XL2 + M4260 Acoustic Analyser is a powerful Sound Level Meter, a professional Acoustic Analyser and a precision Audio Analyser in one instrument. Easy operation and countless applications distinguish this quality Swiss product. The NTi XL2 + M4260 is the ideal tool for taking readings of sound levels at outdoor events.

Get the job done, on time! The instrument is ready to measure literally seconds after you press the power button. The intuitive navigation and flexible user interface assist in simplifying every task. The XL2 provides an extensive range of measurement functions.

The XL2 is developed according to user needs, and provides reliable measurement solutions for sound system installations, noise control, architectural acoustics, evacuation systems, live events, quality inspection and occupational health and safety. Discover an instrument you can trust for specialist applications.

Focus on your core skills and let the XL2 provide you with the reliable measurement data. This instrument is the benchmark that allows you to be the professional that you are. The robust design and verifiable measurement methods pair to help you perform better. The XL2 is the reference instrument in audio and acoustic measurement.

Sound Level Meter – The Flexible Solution

The XL2 is a powerful sound level meter for events and environmental noise monitoring. Numerous measurement variations are available. Actual level, Lmin, Lmax and Leq may be measured in combination with frequency weighting A, C or Z and time weightings fast, slow and optional impulse. All results are simultaneously available.

XL2 Sound Level Meter

All acquired level information can be automatically written to the removable SD card. The XL2 also offers wav-file recording for a complete documentation of the measured sound pressure levels. Additionally you may add a voice note to each measurement saved.


    • Standards IEC 61672, IEC 60651, IEC 60804, ANSI S1.4, ANSI S1.43
  • Sound levels
    • SPL actual, Lmin, Lmax, Lpeak, Leq, gliding Leq
    • Frequency weighting: A, C, Z (=flat) simultaneously
    • Time weighting: Fast, slow and optional impulse simultaneously
    • Correction values k1, k2
    • Indicators show when sound level limits are exceeded
    • Digital I/O interface for the control of external peripherals
    • Sound Exposure Level LAE (optional)
    • Percentile statistics for Lxy (x= A, C or Z, y= F, S or EQ1″): 1 – 99%  (optional)
    • Calculated levels: LCeq – LAeq, LAIeq – LAeq, LAFT5eq -LAeq (optional)
    • Clock-impulse maximum level “TaktMax” in accordance with DIN 45645-1 (optional)
  • Spectrum Analyzer
    • 1/3 octave, 1/1 octave
    • Frequency weighting: A, C, Z (=flat)
    • Time weighting: Fast, slow and optional impulse
    • Percentile statistics for Lxy (x= A, C or Z, y= F or S ): 1 – 99%  (optional)
  • Logging to SD Card
    • All levels simultaneously
    • Short-time levels including spectrum for 1 second or longer
    • Wav-file for playback (compressed)
    • Data logging in 100 ms intervals (optional)
    • Linear wav-files with 24 bit, 48 kHz resolution (optional)
  • Remote measurement acquisition (optional)

Real Time Analyzer RTA

The RTA perfectly suits tasks such as optimization of sound systems and rooms. The XL2 measures and logs wideband values and the real time spectrum in 1/1 or 1/3 octave band resolution in accordance with IEC 61260 class 0. The sound level meter results of the wide band and RTA spectrum are simultaneously available.

XL2 Sound Level Meter

Acoustic Analyzer

FFT Analysis

The real-time FFT is the ideal tool for visualization of comb filters and narrow band effects. It measures the actual level and the averaged level Leq in three ranges over the entire audio band. The optional Extended Acoustic Pack offers an additional high-resolution Zoom-FFT up to 0.4 Hz steps in the frequency range 5 Hz – 20 kHz. The Spectral Limits Option extends the FFT Analysis with trace capturing, relative curve display and comprehensive tolerance handling.

XL2 FFT Analyzer

RT60 Reverberation Time

The XL2 measures the energy decay in the range from 63 Hz to 8 kHz by the Schroeder method in 1/1 octave bands. Automatic triggering and averaging of multiple measurements simplifies the operation and minimizes the measurement time. Use either an impulse source or an interrupted pink noise as the test signal. The optional Extended Acoustic Pack extends the RT60 measurement to a 1/3 octave resolution.

XL2 RT60 Reverberation Time


For a stereo sound image, it is important to match the polarities of the left and right speakers. The XL2 measures the polarity of cables, single speakers and speaker cabinets. The detailed result page displays the measured polarity as octave bands from 125 Hz to 8 kHz. This allows in-depth verification of the polarity – frequency relation. The polarity test signal is provided by the NTi Audio Test CD or the Minirator test signal generator.

XL2 Polarity

Delay Time

The delay function supports the accurate setup of delay lines and thus the optimization of the directionality of the signal source. The XL2 measures the delay time between the electrical reference signal and the acoustic signal from the speaker. The required delay settings are displayed automatically, allowing the audio engineer to set the measured delay time directly into the delay device in the rack.

XL2 Delay Time

Analog Audio Analyser

Level RMS / THD+N

The XL2 with balanced XLR and unbalanced RCA inputs offers a comprehensive, high performance audio analyzer. It simultaneously measures balance, level, distortion (THD+N) and frequency. The internal loudspeaker or headphone output offers audible monitoring of either the input signal or just the residual distortion. The optimized low distortion and low noise design enable level measurements down to -112 dBu and residual distortions typically lower than -100 dB, which is unmatched in handheld instruments.

XL2 Audio Analyzer

Audio Spectrum

Spectral audio measurements are offered in the units Volt, dBu and dBV within the following measurement functions:

  • Sound Level Meter
  • FFT
  • 1/12 Octave (optional)

XL2 Spectral Audio Measurements


The scope function visualizes the waveform of the electrical input signal. It triggers to the fundamental frequency and selects the scaling of the X-axis (time) and Y-axis (level) automatically. The fundamental or most dominant frequency is displayed above the scope screen.

XL2 Scope