NTi Audio XL3
Acoustic Analyzer

  • Class 1 Sound Level Meter
  • Spectrum, Reverberation Time, Sound Insulation Analyzer
  • Multi-Language
  • Touch Display
  • Single-range Measurement
  • Integrated web and file server
  • 8 hours battery life


SKU: XL3 Category:


The XL3 is a professional sound level meter and acoustic analyzer dedicated to noise measurements, room acoustics and building acoustics applications. The intuitive user interface is optimized for basic noise monitoring applications as well as offering extensive analysis tools for professionals. The sound level meter is fully networked and therefore allows operation and data access from any mobile device.

Smart User Interface

XL3 ScreenLayout 1200x500 1

The large 4.3″ IPS color touch display offers an excellent resolution of 480 x 800 pixels. This allows the intuitive control of all measurement functions in multiple languages and presents noise level readings in large, clear digits. Select between a traditional white, blue or black background theme – just as you might do on your smartphone. An additional haptic keypad with eight buttons controls the common instrument functions, such as power on/off for the XL3 and start/stop for the measurement.

Be Connected

The XL3 includes an integrated web server and file server accessible through the instrument’s built-in Wi-Fi or LAN connectivity. Just use your preferred web browser and connect to the sound level meter through the NTi Connect service. The instrument can be controlled by an authorized user from anywhere in the world. Alternatively, you can connect directly to the device’s IP Address through your local network – e.g., in building acoustics, the impact sound level measurement can be started directly from the sending room.

NTi Connect Teaser 1200x500 1

All measurement data can be easily downloaded without interruption to an ongoing measurement. To log prevailing weather conditions, a weather station can be added. Additionally, the online XL3 synchronizes to the actual time automatically using the ntp protocol. This and the optional APIs for controlling the instrument to retrieve historical and current noise, audio and weather data simplifies the integration into monitoring systems.

NTi Connect mobileDevices online


Open Data Format

All measurement data is stored in an open txt-format on a removable 32 GB SD card for download via USB-C. This capacity can be increased to terabytes of storage with a larger SD card or an external SSD. Additionally, an audio signal is recorded.

The XL3 is optimized for integration into customized noise monitoring applications – the sound level readings may be optionally streamed in an efficient binary format. At the same time the live audio is available online for identifying annoying noise sources.


Swiss Precision Engineering

This sound level meter builds on the latest processor and display technologies to provide a comfortable user experience. High-performance hardware packed in a robust housing offers precise 96 kHz data sampling in 32-bit resolution. With a frequency range from 0.3 Hz – 45 kHz, the XL3 is prepared for infra and ultra sound measurements. With single-range measurement and the automated sensor detection reading the electronic data sheet from the connected measurement microphone, the XL3 Acoustic Analyzer is indeed the equivalent of a Swiss Army knife for noise measurement professionals.

XL3 front description 800x800 1

Additional information




The XL3 is a professional sound level meter and acoustic analyzer for noise measurements, room acoustics and building acoustics – optimized for the needs of the acoustician.


Class 1 Sound Level Meter

The XL3 forms a class 1 sound level meter in combination with the measurement microphones M2230 or M2340. All sound pressure levels are measured precisely at the same time and presented in large digits on the color display. Readings exceeding the preset limit turn red indicating non-compliance, while the data is logged in 1 second intervals and the audio is recorded simultaneously. The XL3 is the perfect tool for an easy investigation of noise complaints and long-term noise monitoring. Type approval is pending.

Additionally, the noise spectrum is measured in both octave or one-third-octave resolution, e.g. for tonality investigations, as well as the optional event-marker, back-erase and pre-trigger – all of which extend the sound level meter capabilities for effective attended environmental noise surveys.

XL3 Screen Sound Level Meter

At the same time, the XL3 Sound Level Meter is optimized for unattended noise monitoring. The instrument automatically continues the measurement as soon as power resumes in case of an accidental power failure. The long battery life time and the versatile connectivity options allow online control from your preferred web browser from anywhere around the globe including audio streaming for live listening. A weather station may be connected directly to the XL3 and external devices controlled via the accessory I/O-PCB.

All stored measurement data is available in simple text format. Detailed data evaluation and rating level calculations are carried out in the optional Data Explorer PC Software.


  • Standards
    • Class 1 using M2230 or M2340 Measurement Microphone
    • IEC 61672, IEC 60651, IEC 60804, IEC 61260
    • Germany: DIN 45645-1, DIN 45645-2
    • Japan: JIS C1509-1:2005, JIS C 1513 class 1, JIS C 1514 class 0
    • US: ANSI S1.4:2014, ANSI S1.43, ANSI S1.11:2014


  • Sound levels
    • SPL actual, Lmin, Lmax, Lpeak, Leq, gliding Leq
    • Clock-impulse maximum level “TaktMax” in accordance with DIN 45645-1
    • Calculated levels LCeq – LAeq, LAFT5eq -LAeq
    • 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
    • Calculated levels: LAIeq – LAeq (optional)
    • Digital I/O interface for the control of external peripherals (planned)
    • Sound Exposure Level LAE (optional)
    • Percentile statistics for Lxy (x= A, C or Z, y= F, S or EQ1″): 0.1 – 99.9% (optional)
    • Level-time history graph
    • Back-erase (optional, planned)
    • Pre-trigger (optional, planned)


  • Logging and Reporting
    • All levels simultaneously
    • Short-time levels including spectrum for 1 second
    • Wav-file for listening (compressed)
    • Data logging in 100 ms intervals (optional)
    • Linear audio: 24, 32 bit with 12, 24, 48, 96 kHz (optional)

Noise Spectrum

The XL3 determines the frequency spectrum with a Class 1 filter bank in octave or one-third octave resolution between 6.3 Hz and 20 kHz. The minimum, maximum and average sound pressure levels of all frequency bands are measured in parallel. The frequency axis can be freely zoomed and scrolled to e.g. 125 Hz – 8 kHz for appliance noise investigations. The summed level of the selected frequency range is shown in the spectrum view at the same time.

XL3 Noise Spectrum


  • Class 1 according to IEC 61260 and ANSI S1.11 with filter base 10
  • Octave band: 8 Hz – 16 kHz, one-third-octave band: 6.3 Hz – 20 kHz
  • Leq, Lmax, Lmin with frequency weighting A, C, Z
  • Time weighting: Fast, slow
  • Percentile statistics for Lxy (x= A, C or Z, y= F or S): 1 – 99% (optional)


Reverberation Time

The XL3 measures the reverberation time in octave bands from 63 Hz – 8 kHz using the standardized T20 or T30. The room may be excited using an impulse source or an interrupted pink noise. The Acoustic Analyzer averages all the recorded decays for each measurement position automatically. Additionally, installing the Extended Room Acoustics Option enables reverberation time measurement in one-third octave resolution, visualizing the decay curve, calculating the spatial average of the room and simultaneous T30/T20/T15/EDT measurement on the XL3 Acoustic Analyzer. Additional quality indicators, such as linearity and curvature, describe the decay curve in accordance with the standard ISO 3382-2. An audio file of the level decay may be recorded for more detailed analysis.

XL3 Screen Reverberation Time


  • ISO 3382 and ASTM E2235 based on Schroeder backward integration
  • Octave band: 63 Hz – 8 kHz
  • Measurement parameters T20, T30
  • Impulse and interrupted noise source
  • Automatic averaging for each position
  • 1/3 octave band: 50 Hz – 10 kHz (optional)
  • T20, T30, T15, EDT simultaneously (optional)
  • Calculating spatial room average (optional)
  • Audio recording (optional)
  • Minimum trigger level (optional)
  • Decay curve (optional, planned)


Sound Insulation (optional)

The XL3 Acoustic Analyzer enables direct determination of airborne, impact and facade sound insulation on the instrument. Simply measure in the sending and receiving room and see the sound insulation values displayed for immediate compliance confirmation on-site. For additional partitions with the same source or receiving rooms, the XL3 offers time-saving features by re-using of measurement data from previous measurements e.g. reverberation time data or background noise measurements for a common receiving room. In order to prevent any sound absorption from your body, you can leave the room and control the instrument from your mobile phone using Wi-Fi or the 4G/5G network. Generating the final measurement report for sign-off is easy utilizing the optional Sound Insulation Reporter PC Software.

XL3 Screen Sound Insulation


  • Airborne and impact sound insulation on XL3
  • Standards ISO 16283 and ISO 717
  • Automated measurement data averaging
  • Re-use of existing data
  • Results D, D’n, D’nT and R’
  • Chart and table


Extended Noise Measurement Option

The Extended Noise Measurement Option adds the advanced features below for more challenging tasks of noise consultants.

XL3 Extended

  • Sound exposure level LAE
  • Time weighting: Impulse
  • Level difference LAIeq – LAeq
  • Percentile statistics L% (broadband & spectrum)
  • Logging 100 ms (broadband & spectrum)
  • Audio recording: 24, 32 bit with 12, 24, 48, 96 kHz
  • Level-time history
  • Event-triggered audio and data recording (planned)

NTi Audio #: 

  • Extended Noise Measurement: 600 000 707
  • Extended Noise Measurement 365: 600 000 721
    (annual subscription service)


Extended Room Acoustics Option

Room acousticians value the following optional features for extended reverberation time measurements.

XL3 Extended Room

  • 1/3-octave band: 50 Hz – 10 kHz
  • Early Decay Time EDT, T15
  • T30, T20, T15, EDT simultaneously
  • Minimum trigger level
  • Audio Recording
  • Room Average
  • Decay curve (planned)

NTi Audio #: 

  • Extended Room Acoustics: 600 000 708
  • Extended Room Acoustics 365: 600 000 722
    (annual subscription service)


Sound Insulation Option

Room acousticians value the following optional features for extended reverberation time measurements.

XL3 Insulation

  • Airborne and impact sound insulation
  • Standards ISO 16283 and ISO 717
  • Automated measurement data averaging
  • Results D, D’n, D’nT and R’
  • Chart and table
  • Re-use of existing data (planned)
  • Requires Extended Room Acoustics Option

NTi Audio #: 

  • Sound Insulation: 600 000 709
  • Sound Insulation 365: 600 000 723
    (annual subscription service)


API Programming Interface Option

The API Interface Option enables the integration of the XL3 Sound Level Meter into customer-specific monitoring solutions. The measurement data and the recorded audio may be streamed from any previous date of the ongoing campaign to the cloud or a local server. The XL3 pushes the actual noise data, the state-of-health conditions and the weather data continuously.

  • Control, configuration & data retrieval
  • Data and audio streaming
  • Noise, weather and state-of-health data

NTi Audio #: 

  • API Programming Interface: 600 000 711
  • API Programming Interface 365: 600 000 724
    (annual subscription service)


Type Approval Option (Pending)

The Type Approval Option enables the installation of the type approved firmware in the XL3 Sound Level Meter for certified measurements. The XL3 in combination with the M2230 or M2340 measurement microphone forms a type-approved sound level meter offering class 1 performance in accordance with IEC 61672:2014, IEC 61260:2014, ANSI S1.4:2014 and ANSI S1.11:2014 standard. Type approval is pending.

Type approved sound level meter configuration:

  • XL3 Sound Level Meter
    • M2230 or M2340 Measurement Microphone
    • Firmware V1.01
  • NTi Audio Class 1 Sound Calibrator
  • Optional
    • Extended Noise Measurement Option
    • ASD Cable 5 m, 10 m or 20 m
    • Mains Power Adapter
    • Wind Screen 90 mm
    • Weather Protection WP30


NTi Connect Open Data 365

The XL3 Acoustic Analyzer offers an integrated web server for easy access through the internet using https://connect.nti-audio.com. You can remotely control your instrument and download all measurement and audio files simply from a web page. Alternatively, data can be accessed through sftp using an external application such as WatchFTP.

This NTi Connect service is free up to a monthly data volume of 2 GB. Data download speed for access above 2 GB is slowed down. The NTi Connect Open Data subscription retains the communication at full speed, e.g. for the downloading longer audio recordings.

  • Easy and secure access to webpage and data files
  • Remote API from all around the globe
  • No static / public IP / VPN or port forwarding required


NTi Connect mobileDevices online

  • NTi Connect Open Data 365
  • NTi Audio #: 600 000 734 (annual subscription service)


Data Explorer Software License

Data Explorer is a PC-based software application with a powerful data processor for easy and fast analysis of sound level measurement data recorded by the XL2 or XL3. Visualize, analyze and control millions of data points with this tool that is dedicated to acoustic consultants and noise measurement professionals. It provides a convenient way to view and manage your data and quickly create customized reports.

The import of logged noise level data into the Data Explorer software is enabled by an activated license for the individual instrument.

Level View with Audio Playback


NTi Audio #:

  • XL3 Data Explorer Permanent: 600 000 717
  • XL3 Data Explorer 365: 600 000 730
    (annual subscription service)
  • XL2 Data Explorer Permanent: 600 000 430
  • XL2 Data Explorer 365: 600 000 431
    (annual subscription service)


Room Acoustics Reporter Software License

The Room Acoustics Reporter is a PC software for automatically generating reverberation time measurement reports and analyzing the noise spectrum. The software supports acousticians and experts in the visualization and detailed evaluation of measurement data recorded with the XL2 or XL3 Sound Level Meter.

The import of measurement data into the Room Acoustics Reporter software is enabled by an activated license for the individual instrument.

XL2 Room Acoustics Reporter Results with Tolerance and Material


NTi Audio #:

  • XL3 Room Acoustics Reporter Permanent: 600 000 719
  • XL3 Room Acoustics Reporter 365: 600 000 732
    (annual subscription service)
  • XL2 Room Acoustics Reporter Permanent: 600 000 440
  • XL2 Room Acoustics Reporter 365: 600 000 441
    (annual subscription service)


Sound Insulation Reporter Software License

Sound Insulation Reporter is a PC-based software application that provides all the standard reports for Airborne, Impact and Facade sound insulation measurements. Designed for acoustic consultants, this comprehensive tool uses data gathered by the XL2 or XL3 Acoustic Analyzer, and quickly returns graphical analysis for all measurement positions.

The import of measurement data into the Sound Insulation Reporter software is enabled by an activated license for the individual instrument.

Sound Insulation Results


NTi Audio #:

  • XL3 Sound Insulation Reporter Permanent: 600 000 718
  • XL3 Sound Insulation Reporter 365: 600 000 731
    (annual subscription service)
  • XL2 Sound Insulation Reporter Permanent: 600 000 432
  • XL2 Sound Insulation Reporter 365: 600 000 433
    (annual subscription service)


Measurement Microphones


A range of measurement microphones are available to suit your requirements. The measurement microphones combine with the analyzer for a comprehensive sound level meter and acoustic analyzer.

The microphones are 48V phantom powered and include an electronic data sheet. The Automated Sensor Detection (ASD) of the Analyzer automatically reads this data, i.e. the microphone model and calibration data. This promotes faster setup and ensures accurate measurements.

More info

Microphone PreAmplifier


The MA220 and MA230 offer a low noise microphone preamplifier compatible with standardized 1/2″ microphone capsules. Both include an electronic datasheet for fast setup and ensuring accurate measurements. The MA230 is additionaly enabled for periodic self-tests (Charge Injection Check CIC) dedicated for permanent noise monitoring stations.

NTi Audio #:

  • MA220: 600 040 040
  • MA230: 600 040 200

Weather Protection

NTi Audio Microphone Weather Protection

Protect your measurement microphone from rain, wind, dust and perching birds with a professional outdoor weather protection kit. The corrosion-free polymer housing, wind screen, water-repellent membrane and bird spike provide excellent protection from rain, wind, dust and perching birds. A weather protection is dedicated for precise acquisition of environmental noise data in outdoor applications.

There are two types available. The WP30 Weather Protection is dedicated for the ½” measurement microphones M2230 and M2340. On the other hand the WP61 Weather Protection is designed for the ¼” measurement microphone M4261. An outdoor measurement microphone consists of a measurement microphone and a weather protection.

NTi Audio #:

  • WP30: 600 040 060 (without microphone)
  • WP61: 600 040 080 (without microphone)


NTi Audio Pole Mount Adapter 5 4zoll

The outdoor measurement microphone may be installed on a pole using an adapter. The microphone is connected to the sound level meter by the ASD cable, which runs through the pole and the adapter to the microphone. The adapter is available in two different sizes.

NTi Audio #:

  • Pole Mount Adapter PM 1″: 600 040 067
    supports pole diameter 25 – 33 mm (1-1.3″)
  • Pole Mount Adapter PM 1 1/4″: 600 040 068
    supports pole diameter 32 – 44 mm (1.25-1.75″)


Dehumidifier M2230 WP

The Dehumidifier protects the microphone capsule from possible water damage caused by condensation due to high humidity. This provides reliable and precise measurements in changing environmental conditions. The Dehumidifier is an accessory for the outdoor measurement microphone M2230-WP (= M2230 with WP30) and M2340-WP (= M2340 with WP30).

NTi Audio #: 600 040 063

Class 1 Sound Calibrator


The battery-operated Class 1 Sound Calibrator is classified for the calibration of class 1 measurement microphones, sound level meters and other acoustic measurement equipment. This precision microphone calibrator delivers 94 or 114 dB at a frequency of 1 kHz.

NTi Audio #: 600 000 388

Add the “1/4″ Calibration Adapter” to fit 1/4” measurement microphones into the Class 1 Sound Calibrator. NTi Audio #: 600 000 391

Class 2 Sound Calibrator


The battery-operated Class 2 Sound Calibrator is classified for the calibration of class 2 measurement microphones, sound level meters and other acoustic measurement equipment. This microphone calibrator delivers 114 dB at a frequency of 1 kHz.

NTi Audio #: 600 000 394

XLR Adapter ASD


XLR male/female Adapter with electronic data sheet for automated sensor detection (ASD) of other sensors. The adapter is available in two variations: The type ASD-2 is used for measurement microphones with isolated housing ground connection and the type ASD for induction loop and other sensors.

NTi Audio #:

  • XLR Adapter ASD: 600 000 383
  • XLR Adapter ASD-2: 600 000 385

ICP Adapter ASD


The ICP Adapter connects to the analyzer and generates ICP power supply for other custom sensors. The adapter offers an electronic data sheet, which stores the sensitivity and individual serial number of the connected sensor.

NTi Audio #: 600 010 223

ASD Cable


The ASD Cable allows for extended connections of the NTi Audio measurement microphones. It supports the transfer of the electronic data sheet from the microphone to the Analyzer.

NTi Audio #:

  • 5 meter (16 feet): 600 000 336
  • 10 meter (32 feet): 600 000 364
  • 20 meter (64 feet): 600 000 365

The ASD technology offers the electronic data sheet transfer for cable length until 20 meter (64 feet).

ASD Flat Ribbon Cable 1m


Microphone cable for passing closed windows or doors. It supports the transfer of the electronic data sheet from the microphone to the Analyzer.

NTi Audio #: 600 000 367

Tracer Battery Adapter Cable


The Tracer Battery Adapter Cable connects the Tracer battery pack to an Analyzer. It ensures that the connected instruments start up properly if the battery has been completely discharged.

NTi Audio #: 600 000 478

Ball Head Mount


This flexible universal joint mounts the device on a 1/4″ or 3/8″ stand. It provides the facility to mount the analyzer at any angle.

NTi Audio #: 600 000 387

A 5/8″ stand requires additionally the Mounting Adapter, # 600 000 372.

Mounting Adapter


This mechanical adapter piece mounts the analyzer on a microphone stand. Adapters for 3/8″ or 5/8″ stands are included.

International #: 600 000 372

Lightweight Tripod


Retractable, lightweight tripod with 1/4″ ball head and 3/8″ mounting thread. The flexible ball head mounts the Analyzer at any angle. The tripod is suitable for all measurement microphones, the outdoor microphone and the TalkBox.

Height: 115 – 140 cm, 45 – 55″
Weight: 1.4 kg, 50 oz
Folded: 11 x 8 x 56 cm, 4″ x 3″ x 22″
Unfolded area: 80 x 80 cm, 32″ x 32″

NTi Audio #: 600 000 397

4G/LTE Gateway


The 4G/LTE Gateway is a small, lightweight, and energy-efficient industrial gateway equipped with mission-critical LTE capabilities, Gigabit Ethernet interface, digital Inputs/Outputs, and micro-USB port.

This 4G/LTE Gateway has been specially selected for use with the Sound Level Meter. It connects the analyzer to the internet for remote monitoring of noise levels.

NTi Audio #:

  • 4G/LTE Gateway: 600 076 011
    (worldwide exluding Americas, China, Japan)
  • 4G/LTE Router: 600 076 012

Weather Station


Rain, strong wind and the wind direction can influence the outdoor sound pressure level to be measured. Connect a weather station to your noise measurement station to simultaneously record the noise level and the weather data. Depending on the weather station model used, air pressure, temperature, air humidity, rain, wind speed and wind direction are documented. NoiseScout supports the Vaisala models WXT532, WXT533 and WXT536.

Order Information

  • Weather Station WXT532
    (wind speed, wind direction)
    NTi Audio #: 600 000 736
  • Weather Station WXT533
    (wind speed, wind direction, rain fall)
    NTi Audio #: 600 000 737
  • Weather Station WXT536
    (wind speed, wind direction, rain fall, temperature, air pressure, humidity)
    NTi Audio #: 600 000 738
  • Over-voltage Protection for Weather Station
    NTi Audio #: 600 000 739

Ever-ready Pouch


The Ever-ready Pouch protects the XL3 during transport and operation. With its convenient belt-clip, the XL3 can be kept close by for those tasks requiring both hands. The Ever-ready Pouch allows operation of the XL3 fitted in the pouch.

NTi Audio #: 600 000 735

System Case


This compact system case provides the professional transport protection for work in the field. It offers space for the handheld instruments, cables and connectors.

NTi Audio #: 600 000 701



The backpack provides the professional transport protection for work in the field. It offers space for the handheld instruments and accessories.

NTi Audio #: 600 000 706

Heavy-Duty Outdoor Case


The heavy-duty outdoor case is a professional solution for short- and medium-term unattended noise monitoring. The case provides comprehensive protection against dust, water and impacts. Internal dimensions provide ample space for battery packs to power the Sound Level Meter.

NTi Audio #:

  • IP43: 600 000 704
  • IP65: 600 000 705

Weatherproof Enclosure for Noise Monitoring Terminal


The weatherproof enclosure is the tailored fixed installation solution for unattended noise monitoring. The enclosure is IP66 (without ventilation) or IP55 (with built-in fan) rated, highly secure and constructed of strong, hard-wearing reinforced fiberglass.

The calibration certificate lists the individual product data with serial number. The calibration and adjustment procedures follow the documentation and traceability requirements of the EN ISO / IEC 17025 standard.

Annual re-calibration of the instrument after the purchase is recommended ensuring accurate measurements.

NTi Audio #: 600 000 018

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