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Room Acoustics

Products for Measurement and Calculation of Reverberation Time


Reverberation time is a key parameter in a wide array of venues ranging from concert halls, performance venues, church and worship halls to healthcare and educational spaces. The Larson Davis 831-RT firmware adds reverberation time functionality to test T20 and T30 to ISO 3382-2 and ASTM E2235-04 measurement standards via Integrated Impulse Response (Schroeder method) and Interrupted Noise excitation methods with an automated trigger for easy control. Pink and white noise source is provided to drive omni-directional speakers.  Quality and measurement grade indicators per the ISO standard are built in.

Applications beyond RT measurements include architectural acoustics and absorption coefficient measurement in an easy to use package.

full specs

Larson Davis Class 1 Integrating Reverberation Time Analyzer Kit. 831 with RT option. Provides reverberation time, 1/1 and 1/3 octave, pink and white noise generation, and auto trigger.

  • T20 and T30 measurements according to ISO 3382-2:2008 and ASTM E2235-04
  • 1/1 and 1/3 octave band analysis
  • Supports Integrated Impulse Response and Interrupted Noise excitation methods
  • Built-in pink and white noise generator
  • Automated trigger
  • Display of RT spectrum, individual and ensemble decays
  • Quality indicators to ISO 3382-2

Rental Includes:
831 Analyzer - with reverberation time firmware
377B02 - 1/2" freefield microphone
PRM831 - 1/2" Preamplifier
EXC010 - Microphone extension cable, 10ft
KBAT15 AA - battery kit for short term use, with recharger
PSA029 - AC power adaptor
CBL138 - USB cable to connect to AC adaptor or computer
WS001 - 3-1/2" windscreen
Software Utility - software for meter setup and data download
Accessories - Calibration data, Manual sets, computer interface accessories and an acoustic calibrator

DNA Software
full specs

Larson Davis DNA (Data, Navigation, and Analysis) makes maneuvering through extensive data a simple operation and putting together meaningful reports has never been easier.  Building acoustics capabilities supported are:

  • RT-60 with backward Schroeder Integration
  • ISO R140 and ISO 717
  • ASTM E90-E336 and ASTM E007

Rental Includes:
USB Dongle with Software

Separate instrument driver required

full specs

Larson Davis omnidirectional (dodecahedral) source.  Generates omni-directional sound fields for making standard compliant measurements including reverberation time (ISO 3382, ASTM E2235), building acoustics including insertion loss, acoustic absorption area, (e.g., ISO 140-4 ISO 140-3, ASTM E336, ASTM E90, DIN 55 210). BAS001 is typically used to saturate a room with a uniform acoustic field. The recommended high efficiency power amplifier BAS002-U has no fan for cooling, allowing measurements in quiet environments, perfect for reverberation time applications.

Rental Includes:
Signal Cable - 5 meters long
CCS044 - Carrying case
Technical Manual

Note: TRP023 tripod ordered separately

full specs

Larson Davis directional sound source. Generates homogeneous sound fields using random noise for making standard compliant building acoustics measurements such as insertion loss, acoustic absorption, and more (e.g. ISO 140-3, ASTM E90, ISO 140-5, ASTM E966). The BAS003 is typically used to generate a noise in a free-field for the evaluation of the transmission loss index of a façade. The available high-efficiency power amplifier, BAS002, is light and can be remotely controlled for easy use in the field.

Rental Includes:
Signal Cable - 10 meters long
CCS044 - Carrying Case
Technical Manual

Note: TRP023 tripod ordered separately

full specs

Larson Davis 500 Watt 110-125 BAC power amplifier for BAS001 or BAS003.  Includes remote control and carrying case.

Rental Includes:
Remote Control
Signal Presets - USB flash drive with signal presets
Carrying Case
Technical Manual

full specs

The Larson Davis BAS004 high precision electromagnetic tapping machine is ideal for impact noise generation in buildings per ISO 140, ISO 117, DIN 52210, BS 5821, and ASTME 492. The unit's hammers are raised by an electromagnetic field allowing a frictionless 40mm drop and reduces vibrations caused by mechanically actuated systems. Dimensions of the unit are 10x5x22” (250x120x550mm), and the weight is 26lb (12kg).

Rental Includes:
BP50 - Internal battery for standalone operation
RC50W - Remote control
Soft Carrying Case

full specs

The Larson Davis BAS006 is used to create impulsive noise that includes low frequency energy and avoids problems like secondary bounce. These characteristics make it an ideal choice for measuring reverberation time when the complexity and weight of a speaker and amplifier is not needed. Dimensions of the unit are 24x8x5” (610x203x127mm), and the weight is 11.4lb (5.2kg).

full specs

The NOR277A tapping machine performs impact sound transmission testing according to ISO140, part VI, VII and VIII, ASTM E-492 and ASTM E-1007. Unit has five stainless steel 500g hammers with a 40mm fall each 100mm apart.  A servo system maintains tapping frequency even during temperature changes.  The unit weighs less than 22lbs (10kg) and has a level gauge to aid user when adjusting fall height.  A self-check feedback loop is included: an LED status for each hammer is located on the front panel, and indicates when the impact velocity and tapping frequency meets standards.

Rental Includes:
Battery - Internal battery for standalone operation
AC Power Cord
Remote Control
NOR1336 - Soft carrying case
User Manual

Bruel & Kjaer Type 4204
full specs

Type 4204 is a calibrated reference sound power source ideal for both field and laboratory use. Use 4204 as a reference source when determining sound power output of equipment by various comparison methods including ISO 3741, survey methods per ISO 3747, and measuring environmental correction K2 when determining sound power per ISO 3744. It also can be used in the field of building acoustics to determine the sound absorption and the sound insulation of a room. Type 4204 provides 95 dB nominal A-weighted SPL re 1 pW @ 60 Hz line frequency and also fulfils ISO 3745 and ISO 6926 for calibrated sound power sources.

Rental Includes:
AC Power Cord
6.3 A Fuse
2x 12.5 A Fuses