SPL Documentation

Templates for V-NISSG and DIN 15905-5

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SPL Sense provides value profiles and live screens for the V-NISSG (Switzerland) and DIN 15905-5 (Germany). Which requirements apply to your event is set out in the original documents (below).

Value profiles

Template	Values and thresholds (Notification / Warning / Limit)
VNISSG 93dBA	LAeq 60′: 91 / 92 / 93 · LAeq 5′: – / 92 / 93 · LAFmax 1′: Limit 125
VNISSG 96dBA	LAeq 60′: 94 / 95 / 96 · LAeq 5′: – / 95 / 96 · LAFmax 1′: Limit 125
VNISSG 100dBA	LAeq 60′: 98 / 99 / 100 · LAeq 5′: – / 99 / 100 · LAFmax 1′: Limit 125
DIN 15905-5	LAeq 30′: – / 95 / 99 · LAeq 5′: – / 95 / 99 · LCFmax 1′: Limit 135

The values can be adjusted per measurement, see Value profiles. The matching live screens have the same names as the templates, each also in a variant with leveler display.

Account and interface

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Account

You create an account on spl.cloud with your email address, as described in the quick start. An account is personal: create one for each person and work as a team with organizations instead of sharing one account.

Profile

Settings › My Profile › Edit Profile:

First Name, Last Name, Display Name (how others see you)
Company Name and address
Phone: for SMS alarms. The national format also works (079 …); the cloud converts it to the international format.

Language

Settings › Language: Browser Default, German, German (Switzerland), English or French.

Glossary

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Measured values and notation

SPL Sense and SPL Cloud write measured values as is common in acoustics:

Display	Meaning
LAeq 60′	Equivalent continuous level (Leq), A-weighted, over 60 minutes. The “hourly level” of the V-NISSG.
LAeq 5′	the same over 5 minutes
LCeq 1 s	Equivalent level, C-weighted, over 1 second (live value)
LAFmax 1′	highest level, A-weighted with time weighting Fast, within one minute

The letter after the L is the frequency weighting (A, C or Z), followed by the type (eq or Fmax) and then the time. A prime ′ stands for minutes. The unit is always dB.

Hardware and operating system

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Hardware

You can buy the Raspberry Pi from electronics retailers. We have tested:

Raspberry Pi 4 or 5, Model B (all memory variants)
for power over the network cable: the official Power-over-Ethernet module (PoE HAT) for the Raspberry Pi 3B+ and 4B

Memory card

The memory card is the part most likely to fail after many operating hours. SPL Sense writes little, but a high-quality micro SD card is still worth it. We have had good experiences with “SanDisk Extreme Pro”.

Installation and updates

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Platforms

Platform	Operation
Windows	Desktop app
macOS (Apple silicon and Intel)	Desktop app
Linux on ARM and ARM64, e.g. Raspberry Pi	Web server: operated in the browser, also from a tablet or phone on the same network

The features are the same everywhere. The only exception: you can calibrate the sensor only in the desktop app.

Installation

Platform	Download
Windows (64-bit)	SPLSenseSetup.exe
macOS with Apple chip (M1 and newer)	SPLSense-osx-arm64-Setup.pkg
macOS with Intel processor	SPLSense-osx-x64-Setup.pkg
Linux (Raspberry Pi)	see SPL Sense for Linux

Open the downloaded file and follow the installer. To find out which Mac you have, go to Apple menu › About This Mac: “Chip” means Apple chip, “Processor” means Intel.

Pricing and billing

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The principle

Pro applies per measurement. You activate it for a single measurement or for all measurements of a job.
You pay per measuring day. A measuring day counts if the measurement recorded more than one hour of data on that day. The measurement’s day boundary is decisive.
There is a cap per measurement and year. Once reached, Pro continues free of charge until the end of the measuring year.
No subscription, no base fee. A measurement without data costs nothing.

Prices

You find the current prices on spl.swiss. The model:

SPL Sense API

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Enabling

Settings › API in SPL Sense:

Setting	Values
Mode	Off (default), External Leveler Only, Full Control
Port	Default `8084` (Windows, macOS). On Linux, the API runs on the same port as the web interface, `8080` according to the installation guide; the port setting has no effect there.
API Key	at least 6 characters; set randomly at installation

The page shows the base URL, the Swagger UI and the OpenAPI specification:

User interface and search

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Status bar

The status bar is at the top of every page:

Logo and path: the logo leads to the overview, the path next to it back to higher-level pages.
Device status: shows at a glance what is happening:
- Measurement running (green, with the current LAeq 1 s): a click opens the live screen.
- Measurement stopped or Sensor disconnected (red): a click opens the active measurement.
- No measurement loaded
Connected devices: sensor, leveler and cloud connection, each with its state. If remote control from SPL Cloud is allowed, this is shown here too.
Search (magnifying glass), Help (question mark, opens this documentation) and Settings (gear).

Overview

The overview lists all open measurements as cards. Each card shows the state of the measurement and the values of the last four measurement days, coloured according to the thresholds of the value profile. Below are the completed measurements as a short list.

Installation

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SPL Sense is installed via the command line, either directly on the Raspberry Pi (program Terminal) or via SSH from another computer. With SSH you can copy and paste the commands and avoid typing errors.

Connecting via SSH

Your computer must be in the same network as the Raspberry Pi.

macOS and Linux: in the terminal ssh <user>@<ip-address>, for example ssh pi@192.168.10.144
Windows: in the terminal (PowerShell) also ssh <user>@<ip-address>, or with PuTTY: enter the IP address under Host Name, set Connection type to SSH, then Open

User and password are the ones you set in the Raspberry Pi Imager.

Measurements

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A measurement stands for one measuring point. It contains its settings (value profile, day boundary, offsets, leveler) and all recorded data. A measurement can run over many days and be started and stopped as often as you like.

Flow

create / import
        │
        ▼
     open ──activate──▶ active ──Start──▶ running ──Stop──▶ active (stopped)
        ▲                  │                │ sensor gone   ▲
        │             deactivate            ▼               │ sensor back
        └──────────────────┘           interrupted ─────────┘
        │
    complete ──▶ completed ──re-open──▶ open

Activate: at most one measurement is active at any time; SPL Sense records only into it. You can only switch when the active measurement is stopped.
Start and stop: Start needs a connected sensor. Stop asks for confirmation. If the leveler is active, SPL Sense points out that it will be switched off when stopping.
Interrupted: if the sensor is unplugged or delivers no values for 20 seconds (for example because the computer was asleep), the measurement is interrupted. When the sensor delivers data again, it continues by itself. You end an interrupted measurement with Stop.
Deactivate: Measurement menu › Deactivate. The measurement remains open but is no longer active.
Restart of SPL Sense: after a restart, no measurement is active. If a measurement should continue automatically, use autonomous mode.

Create

On the overview, New measurement:

Measuring point and offset

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Loudest place and measuring position

The limits apply at the loudest place in the audience area. The V-NISSG calls it Ermittlungsort (at ear height), DIN 15905-5 calls it maßgeblicher Immissionsort. The sensor can rarely stand there during an event: in the middle of the audience it would be at risk, and shouting and applause would distort the measurement.

That’s why you measure at another place, the measuring position (DIN: Ersatzimmissionsort). The offset (DIN: correction value) compensates for the difference between the two places. SPL Sense adds it to every measured value so that the displayed and stored values correspond to the level at the loudest place in the audience.

Organizations and roles

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Why organizations?

Everything in SPL Cloud has an owner: measurements, jobs and SPL Sense instances. The owner is either a person or an organization.

An organization is a group of people who access measurements together: a company, a club, a festival or an authority. All members see the organization’s measurements, and when someone leaves the company, the data stays with the organization.

A person can be a member of several organizations, for example as a freelance technician working for several companies. When creating a job or registering an instance, you choose who should own it.

Shared links

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With a shared link, anyone who has the link sees a measurement or a whole job, without an SPL Cloud account. Typical for organizers, operators and authorities, or as a QR code in a festival’s production office.

For people with an account, there is the free read access.

Prerequisite

Link to a measurement: the measurement needs Pro.
Link to a job: the job needs Pro (Activate Pro for the job). Pro on individual measurements of the job is not enough for this.

Creating a link

Menu Measurement or Job › Manage Read Access.
Under Read Access Links: Add Access Link.
Select scope: this measurement or the whole job.
Expiration: the date from which the link stops working. Leave empty if it should not expire. We recommend a date about ten days after the event.
Save.

You then see the link and the QR code. Copy copies the link, for example for an email. You can print the QR code.

Measurement data

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The measurement page looks the same in SPL Sense and in SPL Cloud. What is described here applies to both; differences in the reports are listed at the end.

Measurement days and chart

The data is organized by measurement days; a measurement day ends at the measurement’s day boundary. Each day shows the values of the value profile, coloured according to the thresholds: yellow for Notification, orange for Warning, red for Limit. Show all days displays older days.

Audience noise

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What counts towards the level?

The regulations differ here:

V-NISSG (Switzerland): everything that can be heard at the loudest place counts: sound system, stage, instruments and also the audience (industry recommendation on the measurement procedure).
DIN 15905-5 (Germany): only the sound of the sound system is assessed. Audience and other sources are Störschall (extraneous noise) and should not distort the result. That’s why the standard recommends a measuring position where the audience hardly matters.

In both cases, the SPL Sense recording contains the total level at the sensor. No setting removes the audience from the stored measured values. How much it counts is therefore determined by your choice of measuring position.

Data formats

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CSV

The CSV export is available per day and for the whole measurement, in SPL Sense and in SPL Cloud (there for the whole measurement as ZIP).

Separator: semicolon ;
one row per minute (interval)
first column Timestamp: end of the interval in ISO 8601 format with time zone, for example 2026-07-12T22:15:00.0000000+02:00
then one column per value of the value profile, in its order, with name and unit in the header
values in dB with one decimal place, including offset
decimal separator according to the user interface language

Excluded time ranges, comments and events are not included in the CSV.

Reports and pictures

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Day reports

In SPL Sense, the day report as PDF is free. In SPL Cloud it is available with Pro, in two variants:

Day report: PDF button at the selected day. Without Pro, the button is greyed out.
Day report with deviations: menu Measurement › Open day report with deviations. Additionally contains the exceedances of the value profile thresholds for the selected day.

If the measurement belongs to an organization with a logo, the logo appears in the report. You set the logo on the organization page.

SPL Sense instances

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Every installation of SPL Sense that is registered with SPL Cloud is called an instance: a laptop, a desktop PC or a Raspberry Pi. How to register an instance is described under SPL Sense › Settings.

States

State	Meaning
Measuring	SPL Sense is online and recording.
Connection lost	The instance stopped reporting during a measurement. SPL Sense usually keeps measuring and uploads the data as soon as internet is back.
Online	SPL Sense is running and connected, but not measuring.
Offline	SPL Sense is not running or has no internet. The last contact is shown.

Where to find instances

Status bar: “SPL Sense 3 of 5 online”, with a list of all your instances
Overview, at the very bottom: all instances with state, activity, owner and current level
Settings › Personal Sense Instances and on the page of each organization

Each instance shows the icon of its operating system (Apple, Windows, Linux).

Update

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Automatically

On Linux, SPL Sense updates itself like on the other platforms: when a new version is available, Update available appears on the overview. Stop the measurement and click Update and Update and restart. See Installation and updates.

This works if SPL Sense is set up as described in the installation.

Manually

If the automatic update fails, update via the command line. Connect to the Raspberry Pi as in the installation. The general notes apply here too.

Value profiles

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A value profile defines which values a measurement calculates and from when they count as too loud. It determines the colours on the overview and in the chart, the deviations and the alarms in SPL Cloud.

Structure

A value profile consists of one or more values. Each value has:

Part	Options
Integration Type	Leq (equivalent continuous level) or MaxF (highest level with time weighting Fast)
Weighting	A, C or Z
Time	1 to 60 minutes
Notification, Warning, Limit	thresholds in dB, each optional

Examples: Leq, A, 60 minutes gives LAeq 60′; MaxF, C, 1 minute gives LCFmax 1′.

Alarms

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SPL Cloud checks the running Pro measurements every minute and notifies the registered recipients:

Exceedance: a value is above a threshold of the measurement’s value profile.
Downtime: a running measurement stops sending data, for example because power or internet is gone.

Alarms only run for measurements with Pro. Other measurements in the same scope are skipped.

Where to set up alarms

For a whole job: menu Job › Alarms. The setting applies to all its measurements.
For a single measurement: menu Measurement › Alarm configuration. For an independent measurement, this is the only way. If the measurement belongs to a job, this setting overrides the job’s setting for this one measurement.

At the top of the page you choose the scope: Full Job or Single Measurement. The list below shows the affected measurements and points out measurements without Pro or without limits.

Jobs with several measuring points

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A job groups several measurements that belong together: all stages of a festival, the measuring points of a construction site or a club with a main and a side room. Each measuring point remains a separate measurement with its own sensor, value profile and data. The job shows them together and lets you set access, Pro and alarms for all of them at once.

Jobs only exist in SPL Cloud; SPL Sense only knows measurements.

Live screen and kiosk

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The Live Screen shows the current values large and easy to read, for example on a second display for the DJ or the technicians. You open it on the measurement page with Live Screen or by clicking the device status in the status bar.

Choosing a screen

Choose the screen at the top right of the live screen. SPL Sense remembers per measurement which one was used last.

Operation

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Addresses

With port 8080 from the installation:

	Address
Web interface	`http://<ip-address>:8080`
Live screen	`http://<ip-address>:8080/measurement/live`
Live screen in kiosk mode	`http://<ip-address>:8080/measurement/live?kiosk`
SPL Sense API	`http://<ip-address>:8080/api`

On the Raspberry Pi itself, you can use localhost instead of the IP address.

Kiosk display

For a permanent display, for example a screen at the DJ booth, the browser opens the live screen directly in kiosk mode, for example with Chromium:

Leveler

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The leveler automatically keeps the level below a limit. SPL Sense measures the sound level with the sensor, receives from the leveler device the level of the signal it is currently outputting (line level), and calculates how much the volume must be reduced (gain reduction). The leveler device applies the reduction in the signal path.

The leveler belongs to the measurement: each measurement has its own leveler settings. You find them in the Measurement menu › Leveler Settings.

Measurements in the cloud

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A measurement appears in SPL Cloud as soon as its Cloud Uplink is switched on in SPL Sense and the instance has internet. New measurements are listed first under the independent measurements on the overview.

The measurement page

Below the title, a line shows the essentials: job, owner, the instance currently measuring (with state), and whether Pro is active.

Live: while the measurement is running, you see the current 1-second values, with an active leveler also gain reduction and correlation. If the instance stops reporting, Connection lost is shown with the last contact.
Days, chart, deviations and events: the same as in SPL Sense, see Evaluating measurement data.
On the side: access (who sees the measurement), Pro, pictures and the other measurements of the same job.

If something about the measurement changes in SPL Sense, for example the offset, the page updates itself.

Remote control and comments

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With remote control, you operate SPL Sense from SPL Cloud, for example a Raspberry Pi in a rack or a laptop at another stage.

Prerequisites

Allowed in SPL Sense: Settings › Cloud › Allow remote control. Off by default. This way the person on site always decides whether their instance may be remote controlled.
Instance online: commands only go to a connected instance. There is no queue.
Pro on the measurement: only measurements with Pro can be controlled.
Permission: the owner of the instance; for an instance of an organization, all members. People with read access or a shared link can never control.
SPL Sense version 2.0 or later.

What is possible

On the instance or measurement page, in the Remote control area:

Read access

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With read access, another person sees a measurement or a whole job without being able to change anything. Typical for organizers, operators or authorities.

There are two kinds:

	Read access	Shared link
For	people with an SPL Cloud account	anyone who has the link or QR code
Cost	free	SPL Cloud Pro
Revoking	per person	per link, or with an expiration date

This page describes the free read access.

Sensor and calibration

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Sensor information

Under Settings › Sensor Information (or by clicking the sensor on the overview) you see:

Device Information: serial number, hardware revision, MCU ID, firmware version, quality check
Voltage and MCU Temperature, refreshed with Refresh measured values
Calibration: date, by whom, valid until
Weather Protection: the compensation filter that is set

Always connect only one sensor to a computer running SPL Sense. If you change the sensor during a measurement (unplug, plug in another), SPL Sense continues measuring with the new one; the affected minute is marked in the data.

Autonomous mode

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In autonomous mode, SPL Sense activates and starts a specific measurement by itself as soon as SPL Sense starts. This is intended for permanently installed systems, for example in a club or on a Raspberry Pi: after a power failure or restart, the system continues measuring without intervention.

Setup

Settings › Autonomous Mode.
Set Automatically run a measurement when running to On.
Choose the Measurement. Only open measurements are offered.
Save. If SPL Sense is stopped and a sensor is connected, SPL Sense offers to start the measurement right away.

Behaviour

When SPL Sense starts: the chosen measurement is activated and started. If no sensor is connected, the measurement is Interrupted and starts recording as soon as the sensor is there.
Stopping: you can stop the measurement at any time. It then stays stopped until SPL Sense starts the next time.
Completing: when the measurement is completed, autonomous mode switches itself off.
Calibration: with the automatic start, SPL Sense does not ask, even if the calibration has expired. The events show the reason Automatically started as autonomous measurement.

For unattended operation

Combine autonomous mode with:

Settings

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Open the settings with the gear at the top right. Each row shows the current state.

Group	Settings
Measuring	Value Profiles, Live Screens, Autonomous Mode
Device	Sensor Information, Leveler, Update
Access and connections	Operator PIN, Cloud, API, Language
About	Version, release notes, contact, privacy, open source licenses

Operator PIN

An operator PIN protects SPL Sense against changes. Without a PIN, anyone with access to SPL Sense can change everything.

Settings › Operator PIN.
Enter a New PIN (4 to 8 digits) and repeat it.
Save.

With a PIN set:

Search Results

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