13 dB lower noise with NI Module 9250

noiseLAB 4 can now support NI 9250 giving about a 13 dB lower noise floor than with NI 9233 or 9234.  The typical A-weighted noise floor with a 50 mV/Pa half-inch instrumentation microphone is about 20 dB (A)

Before you upgrade, please carefully note the following:

  1. The 9250 has two channels instead of four (for the 9233 and 9234)
  2. The 9250 has 2 mA transducer powering (IEPE), and just like the 9233/34, additional powering must be applied to provide the 4 mA for microphones with a 20 dB gain preamp. However, the lower noise of the 9250 significantly reduces the need for the 20 dB preamp gain.
  3. Chassis: Older USB carriers and chassis such as the NI USB-9162 and NI cDAQ NI 9172 cannot be used with the 9250. You must use newer generation chassis such as the
    • NI USB-9171 (one slot)
    • NI USB-9174 (four slots)
    • (NI USB-9178 (eight slots) (The current edition of noiseLAB only supports 8 channels))
    • [Ethernet versions of the above have not yet been tested for compatibility]
  4. Drivers: noiseLAB Capture 4.0 and later must have the National Instrument data acquisition drivers upgraded to DAQmx 14.0 but no higher than DAQmx 18.0. Note: Carefully check any other National Instruments programs you have installed, along with associated NI hardware, to ensure compatibility with the above mentioned range of DAQmx drivers.    Contact National Instruments for detailed information (ni.com).
  5. noiseLAB 3 is not compatible with the above drivers and modules.

CTXI provides paid support to help you in the upgrade process at a price of €300.  Contact Carsten Thomsen at ct@pxi.dk.

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Peak measurements in noiseLAB Capture

If you are making A, B, or C-weighted Peak sound level measurements with noiseLAB Capture, please note that Capture does not apply these weightings to the Peak value, and always measures it with the Linear weighting, even if you have selected and A, B, or C weighting.

noiseLAB Batch applies the selected weighting to Peak, as well as to all other sound level types such as Fast, Slow and Impulse.

If you require additional information, you can contact Carsten Thomsen ct@pxi.dk .

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Cure your dB headaches!

Have you ever had trouble adding decibels, and wonder why 0+0=3?

Or if you measure a level of 30 dB and the background noise is 20 dB, how much should you correct the measured value?

What is the free field sound level at 10 meters from a point sound source with a source power level of 98 dB?

How many Pascals is 94 dB?

What is the sensitivity in mV/Pa for a microphone with a sensitivity given as -26 dB re 1V/Pa?


What is the Doppler Frequency  Shift of a 1000 Hz tone of a car passing at 5 meters from the observation point at a speed of 10 m/s?


What is the measurement accuracy on a random noise signal filtered with a 1 kHz octave filter and averaged for 1 second.


Solve these and many other simple acoustic calculations with noiseLAB Calculator.  It’s free, ad- free, and with no obligations.

Read more here and download for free.

–OK, obviously we wouldn’t object to you sometime purchasing our noiseLAB Pro Software…;-)


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Notes on noiseLAB on Windows 7 and 10

Current Versions of noiseLAB 4.0.4 and noiseLAB Batch Processor 4.1 run on Windows 10.

Please note the following:

  1. noiseLAB assumes placement of your project files under Documents\noiseLAB Pro Projects\.  However, Windows, by default does not permit programs to write in folders placed in the root of the boot drive (normally the C drive). If you have project folders in a folder at the root of the C drive, you must run both noiseLAB Capture and noiseLAB Batch “Run as Administrator”
    • to be able to store results to these locations
    • for noiseLAB to properly remember locations for save and get operations. –Note:  the above considerations do not apply to other drives than the Boot drive.
  2. Windows Scales and fonts and other settings should be set to 100%. To find these settings in Windows 10, right click on your Desktop and select “Display Settings”. On some computers, the appearance may or may not be correct with other scalings than 100%.
  3. A few front panel fonts on the front panel of noiseLAB may be incorrectly sized. To fix this, add the following three lines to the configuration file for noiseLAB Capture file (.ini) also called Configuration Settings:

appFont=”Tahoma” 13
systemFont=”Tahoma” 13
dialogFont=”Tahoma” 13

This may not work properly for all keyboards etc.  Instead try one of the following:

  1. then copy the lines from the attached pdf file into the .ini file: appFont
  2. or edit the .ini file manually and replace the six quotation marks, with those from your native PC keyboard.


and paste them into the .ini file.

This .ini file (Configuration file) is located at the following path location:

C:\Program Files (x86)\DELTA\noiseLAB Capture 4.0\

Double click to open the file and add the three lines to the end of the file.  If Windows does not allow you to save the file at its original location, then save it to your Desktop, and drag the file back to the original location, overwriting the original file. It may prompt for Administrator approval when you do this.

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noiseLAB 4 Power User Course: April 7, 2017

This half-day course will quickly move you from being a beginner to a power user that works efficiently and confidently with noiseLAB.  We show how you can go from calibration to report ready results in less than three minutes.

And if you are an experienced user of noiseLAB, you may be surprised that you may learn many new tips and tricks to make you even more skilled.

  • Shortcuts to speed up your work.
  • Graph use:
    • Advanced  auto scaling,  how to prevent “jumpy” graphs
    • Manual axis setting
    • Cursor grabbing, setting and finding.
    • Graph Size and background color
    • Peak or Valley search
  • High speed editing
    • Choosing channels to clip or exclude
    • Full Screen editing
    • User-defined channels to clip
    • Automatic naming with user-defined templates.
    • Renaming of Recordings and Clips
    • Changing of Time Stamps.
    • Adjusting the duration of clips
    • Clip padding before start and end.
    • Understanding mother-child relationships for Recordings and Clips
  • Calibration
    • “Live” calibration using acoustic calibrator
    • Calibration by “stealing” a known calibration tone value.
    • Calibration by manual entry.
    • Verifying quality of acoustic calibrator
      • Frequency and Amplitude stability
      • Distortion
  • Understanding the “Preview” Graph
    • Functions shown
    • Overload indication
    • Relationship to Clips and Recordings
  • Analysis types
    • Weighting network used
    • Parallel analysis results
    • Performance considerations: How noiseLAB shows you the processing metrics
  • FFT Spectrum
    • What is the allowable block size?
    • Zoom vs. 0.1 Hz maximum resolution
    • Export of FFT to Excel
    • Window choice
  • Octave Analysis
    • 1/1 to 1/24 octave
    • Settling time of filters:
      • How is this indicated
      • What considerations must I take for short Clips.
  • Sound Level
    • Parallel measurements
    • Why noiseLAB often is more accurate that your sound level meters.
  • Wave file import and export
    • Sampling frequencies
    • How to calibrate
    • Maintaining calibration for Exported .wav files.
  • Batch Processor
    • Differences to noiseLAB Capture
    • Time and Frequency Slice analysis
    • Graph exports with documentation: Easy to put in report.
  • Overview of Advanced Topics
    • Tone Analysis
    • Impulse Analysis
    • Sound Quality
    • Vibration Measurements

Course Date: Friday April 7, Aarhus, Denmark. 10.00-14.30

Price per person:  2500 DKK

Course Language: English or Danish depending on course participants

Registration: Send e-mail to Carsten Thomsen ct@pxi.dk or contact at +45 40 82 77 72.

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New Sound Propagation Software Released.

SPL 2000 is an updated version of exSOUND2000 featuring

  • Greatly improved user interface
  • Updated Sound Source models.

The program is sold as an experimental research tool, and requires that the user has a thorough understanding of the Nord2000 model.

Software delivery is typically two working days directly from FORCE Technology.

Educational users:  Please contact FORCE directly at erth@force.dk .

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noiseLAB for Multi-channel Use

noiseLAB supports up to 8 simultaneous parallel acoustic channels.

The following is a guide to configuring this most economically:

2-4 channels:

  • For a noise floor of about 30 dB(A) use one National Instruments USB 9234 with four active microphone channels.
  • For a noise floor of about 17 dB(A) use a microphone preamp with 20 dB gain and two active channels.  This gain setting requires additional power from the USB 9234, therefore only two channels can be used and each channel must be coupled in parallel to an  unused inputs to get sufficient powering.

4-8 channels (partial synchronization)

  • User two National Instruments 9234.
  • With a noise floor or 30 dB(A) you can use up to 8 channels.
  • With a noise floor of 17 dB(A) you can use to up 4 channels as described above.
  • The two channels in each 9234 are synchronized, but the two 9234 devices are not synchronized between each other.  Hence precise time relationships cannot be determined, since the internal clocks in the 9234s may drift several seconds per day.

4-8 channels (full synchronization)

  • Solution 1: Use two National Instruments 9234 in a CompactDAQ Chassis cDAQ 9174 which synchronizes the two modules.  The powering constraints described above are the same.
  • Solution 2: Use the National Instruments PCI 4474 (four channels) or PCI 4472 (8 channels)  in a PC with a full size PCI slot.  (Note: PCIe slots cannot be used).   These cards provide 4 or 8 fully synchronized channels, and 8 dB greater dynamic range than the NI 9234.  In addition, each channel provides sufficient powering to drive preamps with 20 dB gain.  Finally, twice as high sampling frequencies as the 9234 are supported.


  • Two USB digitizers connected to  noiseLAB must be identical and configured with the same sampling frequency.
  • The 9233 is NOT recommended since it cannot turn off its IEPE powering, and also has  “end of life” status at National Instruments.


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Beta Software posted

January 26, 2016: A beta version of noiseLAB Batch Processor has been posted with new features and bug fixes.

Also posted is a patch to noiseLAB Capture which makes it possible to read project files which have been moved.

You can download the files here.

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noiseLAB Express upgraded

noiseLAB Express is getting upgraded to noiseLAB Standard Edition.

As of January 4, 2016, noiseLAB Express will be replaced by the noiseLAB Standard Edition

  • The price is unchanged.
  • Two channel capability
  • Increased recording time to 1 hour maximum.
  • Has project file compatibility with noiseLAB Advanced and noiseLAB Professional.
  • Existing licensed users of noiseLAB Express can receive a license key to noiseLAB Standard Edition
  • Existing users should keep their current noiseLAB Express installation since its project file format is not compatible with noiseLAB Standard through Professional Editions.
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noiseLAB Advanced User Course

noiseLAB: Advanced Users Course

noiseLAB 4.0 has more than meets the eye. Under its deceptively simple user interfaces you will find surprising power.

  • Understanding the noiseLAB Architecture–and its benefits
    • Architecture
    • Work flow
    • Data formats
  • Work Faster
    • Faster Import, Calibration, Editing and analysis.
    • Short cuts, tips and tricks.
    • Parallel processing. Getting the most from your PC.
  • Achieve higher quality
    • Scrubbing, listening, and auditing.
    • Editing: Advantages and pitfalls.
    • Documentation: Completeness and consistency.
    • Achieving confidence/re-working of results.
    • Calibration
  • Choosing and using the right hardware:
    • Hard Disk (Flash Recorders), Sound Level Meters, or PCs with digitzer front end.
      • Advantages/disadvantages
      • Traceability/Risk
      • Documenting your work in the field.
      • Calibration: also with variable gain.
    • Microphones and Calibrators.
    • Difference between manufacturers “accuracy”. Things to watch out for.
    • Documentation and best practices.
    • Wireless front ends.
    • Standards conformance of PC Based systems: IEC requirements.
    • Tips for optimizing dynamic range, accuracy and preventing overload/underrange.
  • Auditing and editing your signals.
    • Validating your calibration
    • Tracking gain changes
    • Pre-filtering of Recordings
  • Analysis Functions in depth
    • 1/N octave: Settling times, filter shapes, center frequencies, time slices.
    • Sound Level Functions: Fast, Slow, Peak, Impulse, statistics.
    • FFT: Line spacing, FFT Blocks sizes, weighting functions, time slices and overlap.
    • Time and frequency slices.
    • Tone Analysis: IEC and Danish methods
    • Nordic Impulse Method
    • Sound Quality metrics
    • Vibration Analysis
      • Calibration
      • Analysis types and units.
  • Resulsts and report generation
    • Division of tasks between noiseLAB and Microsoft Office.
    • Data export to Excel and Word of Results Tables and Graphs.
    • Export of Time Slice Graphs.
  • Data import of raw signals, FFT Spectra and noiseLAB 3 projects.
  • Data management, storage, and backup: best practices.
  • The secrets of the TDMS file format and how you can use it.
  • Optimizing performance.
  • Platform issues, IT department cooperation
  • Tips and tricks: Bring your own three best tips and tricks or applications.
  • Common mistakes! Bring your own experiences and share!
  • Product Support, upgrade and licensing policies.
  • Product round table: Questions, suggestions for new functions.

Invitation noiseLAB Advanced Users Course

Course Language: Danish or English depending on participants.

Discounts: Paid participants will receive a 1000 DKK discount on as follows:

  • upgrades between editions (for example from Standard to Professional)
  • upgrades to a new major version. (from 4.0 to Version 5).
  • New purchase of noiseLAB.
  • Second (and third etc.) user License (which has a list price of 50% of the first license) will also be discounted by 1000 DKK.  Discounts only valid for purchases made in the same calendar year.


Carsten Thomsen +45 40 82 77 72



noiseLAB: Work Fast, Work smart.

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