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PPM and Loudness Meter LM 128P

German Version: Loudness Meter LM1128 und LM 128P )

Loudness and Peak Program Meter according to EBU R 128

LM 128P Front View


  • Preface
  • Properties
  •     Inputs
  •     Display
  •     Operation
  • Technical Data
  • Connections
  •     Digital Audio Inputs
  •     Analog Inputs (optional)
  •     Remote Control
  •     USB Connector
  • LM 128P Video Play
  • Operating Manual
  • Preface

    LM 128PVThis PPM (Peak Programme Meter) and Loudness Meter was a joint development with Estec GmbH. It is designed for professional use, mainly in radio and television studios and used by well-known broadcasting organisations.

    The LM 128P still contains part of the "DNA" of the DPLCMs, but has undergone significant further development and redevelopment. Even now, an FPGA is the core of the device.

    In a further development a vertical version of the LM 128P, the LM 128PV was designed. Originally, the LM 128P was created under the name LM 1128 as a pure loudness meter, but with 6 channels for surround sound. The combined version as stereo PPM and loudness meter was then more successful.

    LM 128P InnenI don't want to withhold a glimpse inside from those interested in technology either.

    Unfortunately, the Estec company no longer exists, but I still have a few of these devices, most of which are equipped with analog inputs.

    I present the device here in the form of excerpts from the manual, so that it is not completely forgotten:


    The Estec LM 128P is a Loudness and PPM Meter according to the EBU-recommendation R 128. It fulfills the demands for the „EBU Mode“ corresponding to the specifications

    For more information please refer to http://tech.ebu.ch/loudness.
    Note: The LM 128P does not incorporate a true peak meter according to EBU R 128.



    LU Display Mode

    PPM Display Mode

    Common in both Display Modes


    Technical Data


    LM 128P-Rear

    Digital Audio Inputs

    AES Input

    This is an AES/EBU resp. AES3 input. With a matching adapter also AES3id (BNC) or S/P-DIF (RCA) signals can be applied.

    3G-SDI Input/Output (optional)

    The optional 3G-SDI input/output provides a 4 stereo channel audio de-embedder for data stream 1. These 4 stereo signal pairs can be selected to be measured. The green LED „LOCK“ will be on, when a valid SDI signal is detected.

    Sample Rates

    The LM 128P operates with the following 15 sample rates where the filter coefficients are automatically chosen correctly for 1 kHz reference frequency:
    8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 64, 88.2 and 96 kHz (also 128, 176.4 and 192 kHz in a version without USB)
    For all other sample rates the filter coefficients of the closest known frequencies are chosen.

    Analog Inputs (optional)

    An optional analog stereo input is available on two XLR jacks.

    Remote Control

    The LM 128P is equipped with a remote control input with a 3-pin TRS (Tip, Ring, Sleeve) jack. With external keys it is possible to

    USB Connector

    The LM 128P is equipped with a USB port for reading the loudness measurements and for remote control of the most important functions. An impression of these functions can be obtained from the user interface of our demo program:

    LM-1128 COM-Test

    LM 128P Video

    Have a look at the LM128P in action (unfortunately only in German):

    Start LM128P Demo-Video

    Operating Manual

    Current user manuals in firmware version 4.0x are available as PDF files, but with the logo of our joint company SSB, which also sold the loudness meters:

    LM 128P Anschluss und Bedienung Deutsch
    LM 128P Installation and Operation English

    Last update: August 6th, 2021 Questions? Suggestions? Mail Me! Uwe Beis