Frequently Asked Questions

About Larson Davis Sound and Vibration Products

  • How do I connect the 426A12 outdoor microphone to a Model 820, 824, or 870 sound level meter?

  • How do I upgrade the firmware on my HVM100?

  • How do I update the firmware in my model 824 sound level meter?

  • Can I have a 4-20mA output from the sound level meter?

  • Why does the sum of filters not always match the overall reported level?

  • How do I connect a Hydrophone with an 831?

  • What is the difference between the Model 831, SoundExpert LxT and SoundTrack LxT?

  • What firmware options and accessories will my Model 831 support?

  • What are the 831 and LxT key functions during instrument boot up?

  • Why can I not connect a meter when using SLM Utility G4 or G3?

  • How does the RT60 implementation on the Model 831 differ from the 824?

  • How do I combine Model 831 and DNA for RT60 measurements?

  • How can I get my instrument calibrated quickly?

  • When do I need to use the Type 2 Adapter for circumaural earphones?