SPL Sense

• 1: Installation and updates
• 2: User interface and search
• 3: Measurements
• 4: Measurement data
• 5: Value profiles
• 6: Live screen and kiosk
• 7: Leveler
• 8: Sensor and calibration
• 9: Autonomous mode
• 10: Settings

1 - Installation and updates

Platforms

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

Installation

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.

First start

On first start, SPL Sense shows a privacy notice. Accept and Continue proceeds, Close Application closes SPL Sense.

Updates

SPL Sense checks by itself whether a new version is available. If so, the notice Update available appears on the overview with the buttons Update and Remind me later.

1. Stop a running measurement. No update can be installed during a measurement.
2. Click Update and then Update and restart.
3. SPL Sense downloads the new version, installs it and restarts.

If SPL Sense does not restart by itself after the update, start it manually. After a restart, no measurement is active unless autonomous mode is switched on.

The current version and the version history are under Settings › About.

Where the data is stored

SPL Sense stores all measurements locally on the computer:

Back up this folder regularly or switch on the Cloud Uplink for your measurements. You back up individual measurements as .splsense files, see Import and export.

2 - User interface and search

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.

At the top right, New measurement creates a measurement and Import restores a backed-up measurement.

At the bottom of the overview you find the connected sensor, a connected leveler and, if available, a notice about an update.

Measurement page

• Page header: name, state and the most important actions as buttons, for example Start or Stop. All other actions are in the Measurement menu. Actions that change the measurement permanently (Deactivate, Complete) are at the end of the menu.
• Live strip: while measuring, you see the 1-second values and, if active, the leveler below the page header.
• Days and chart: select a measurement day; the chart shows its course. Next to the day you find the buttons PDF (day report) and CSV.
• Below: deviations, events, sensor and cloud uplink.

What the values and markers mean is described under Measurement data.

States of a measurement

More under Measurements.

Search

Open the search with the magnifying glass or with Ctrl+K (Mac: ⌘+K). It finds measurements (open and completed), settings pages, value profiles and live screens. Use the arrow keys to select a result and Enter to open it.

You can also find settings by keywords, for example “password” for the operator PIN or “limiter” for the leveler.

Use on tablet and phone

In web server mode (Linux) you operate SPL Sense in the browser, also from a tablet or phone. The interface adapts to small screens: the path in the status bar becomes a back link, lists are shown one below the other.

3 - Measurements

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:

A new measurement is not yet active. Its leveler is set to SPL Tools L1 (USB) and mode Off.

Edit

Measurement menu › Edit Measurement. Possible as long as the measurement is not running, not interrupted and not completed. You can also edit a measurement that is not active while another one is recording.

• Name, Day Boundary
• Cloud Uplink: switching it on uploads all data of the measurement, including what was already recorded. Switching it off stops the upload; what is already in the cloud stays there.
• Offsets for A, C and Z, see below
• Value Profile: adjust it with Edit Value Profile

If you change the day boundary or value profile, SPL Sense recalculates the limits and measurement days. Every change of the offsets and of the value profile appears in the events.

You edit the leveler settings separately; they can also be changed during the measurement.

Offsets

The offset converts the values at the measuring position to the loudest place in the audience. How to determine it is described under Measuring point and offset.

There are two ways:

• Tune offsets (Measurement menu): with live values. Only for the active, stopped measurement with a connected sensor. The table shows, per weighting, the current level, the highest level since Reset max values, the offset and both values including the offset. Nothing measured here is recorded.
• Edit Measurement: enter offsets directly as numbers, for example from a measurement with a handheld meter.

A changed offset applies from the next start. Data already recorded keeps the offset it was recorded with.

Complete and re-open

When the event is over, complete the measurement: Measurement menu › Complete measurement. The measurement must be stopped. After that it is locked: it can no longer be activated, edited or started, but it can be viewed and exported. If autonomous mode is set to this measurement, it is switched off.

You re-open a completed measurement in the menu with Re-open measurement.

Deleting

You delete an open measurement under Edit Measurement › Delete measurement, a completed one in the Measurement menu. It is only deleted on this computer; what is in SPL Cloud stays there. How to delete the measurement in the cloud as well is described under Measurements in the cloud.

Import and export

A measurement can be backed up as an .splsense file and read in again on another computer, with all data and settings.

• Export: complete the measurement and click Export measurement.
• Import: on the overview, Import, then drag the file into the field. If the measurement already exists, you can replace it with Overwrite existing measurement.

You export the values as a table in CSV format, see Measurement data.

4 - Measurement data

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.

The chart shows the course of the selected day:

• the values of the value profile as lines, the rating as a coloured band
• comments and events as markers
• excluded time ranges greyed out
• with an active leveler, also the signal level (line), the gain reduction and the correlation

The first values appear after the first full minute of recording.

Interval details

A click into the chart opens the details of the minute at that point (an interval): all values, the spectrum in third-octave bands and the check results. Use the arrows to move to the previous or next minute.

Deviations

The Deviations section lists, per value of the value profile, when the selected day exceeded a threshold, with the highest value. A click on an entry draws the thresholds into the chart.

Events

The Events section lists everything that happened with the measurement, newest first:

• recording started and stopped, with reason (for example manually, autonomous mode, microphone disconnected, sleep mode, sensor reconnected)
• measurement created, activated, completed, re-opened
• offsets, value profile and leveler settings changed, each with the old and new values
• leveler bypassed and re-enabled
• comments and changed excluded time ranges

If a change came via SPL Cloud or the API, this is indicated; for the cloud, also by whom.

Comments

With Add › Add comment in the Events section you record something at a point in time, for example “Encore” or “Offset checked with handheld meter”. Comments appear in the chart and can be edited later. For a completed measurement, comments are only possible up to the time of completion.

Excluding time ranges

Some periods should not be included in the rating, for example tuning the system with pink noise before doors open. With Add › Exclude a time range you define such a range with From, To and a comment.

An excluded range:

• is greyed out in the chart and marked Not counted
• does not count for maxima, the rating according to the value profile and the deviations
• is kept with all measurement data

Count again? removes the exclusion. Every change appears in the events.

Reports and exports

In SPL Cloud, the day report (also with deviations) and a pictures report are available with Pro.

Cloud uplink

If the cloud uplink is switched on, the measurement page shows the upload status: Online, Offline and how many intervals, events and leveler statistics are still waiting for upload. Without internet, SPL Sense keeps measuring normally and catches up with the upload.

5 - Value profiles

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:

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

Averages are calculated as moving averages: LAeq 60′ is, at every minute, the average over the preceding 60 minutes, also across the day boundary and across pauses. A value counts as above the threshold if it exceeds it; exactly equal is still fine.

Built-in templates

SPL Sense provides templates for Switzerland (V-NISSG) and Germany (DIN 15905-5). The values are listed under Templates for V-NISSG and DIN 15905-5. Built-in templates cannot be changed.

Your own templates

Under Settings › Value Profiles › Create you create your own templates:

1. Enter a Name.
2. Add the values you need with Add Value and set the thresholds.
3. Click Save.

You can change or delete your own templates at any time. Measurements that use a template are not affected: the template is copied into the measurement when it is created.

Changing the value profile of a measurement

Measurement menu › Edit Measurement › Edit Value Profile. Here you choose another template or adjust the values directly. If the profile differs from its template, SPL Sense indicates this; Reset profile to template values restores the template’s values.

When saving, SPL Sense recalculates all previous measurement days with the new profile. The measurement data itself does not change. The change appears in the events with the old and new profile.

6 - Live screen and kiosk

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.

Screens for common cases are built in, each with and without leveler display:

Custom screens

Under Settings › Live Screens › Create:

1. Enter a Name.
2. Add widgets with Add.
3. Arrange them on the grid: drag a widget to move it and its corner to resize it. With the keyboard: arrow keys move, Shift + arrow keys resize.
4. Select a widget to change its type or set its Color Thresholds.
5. Save.

The preview shows placeholder values at real size, so you can see how large the numbers will be. On narrow screens the widgets are stacked.

Widgets

Color thresholds

Numeric widgets change colour when a value exceeds a threshold. You set the thresholds manually or take them from the measurement with From value profile. This only works for times above one minute, because the value profile knows no shorter times.

Full screen and kiosk

Full screen switches the live screen to kiosk mode: instead of menus, a slim bar shows only measurement, screen, time of the last value and device status. The widgets fill the whole screen, even on a large TV. Leave full screen returns.

If an operator PIN is set, SPL Sense asks for it when leaving the live screen and full screen. This way nobody at the DJ booth can change the settings.

For devices that should start directly into the live screen, see SPL Sense for Linux › Operation.

7 - Leveler

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.

Variants

For Q-SYS there is the plugin SPL Sense Leveler: download. Add it to your Q-SYS design and enter the IP address of the computer running SPL Sense, the port and the API key in the plugin. In SPL Sense, under Settings › API, the mode External Leveler Only or Full Control must be switched on, see SPL Sense API. If the settings are correct, the plugin shows the state and the measured values of SPL Sense.

SPL Tools L1 via USB

Connect the L1 via USB. In the measurement’s leveler settings, Leveler Connection then shows Connected with type, serial number and firmware.

SPL Tools L1 via network

1. Choose SPL Tools L1 (network).
2. Enter the name or IP address of the L1 under Host, or click Search: SPL Sense then looks for L1 devices on the local network.
3. Enter the API Key of the L1.
4. Choose the Security:
   • HTTP (L1 TLS off): unencrypted, only in protected local networks
   • HTTPS, pinned certificate: encrypted with the L1’s own certificate. Read the fingerprint with Read from L1 and compare it with the one shown on the L1.
   • HTTPS, trusted CA: encrypted with a certificate from a recognized authority
5. Click Test connection and then Save.

The easiest way is Set up from L1 on USB: plug the L1 in via USB once, and SPL Sense takes over host, API key, security and fingerprint. If the L1 has no API key yet, SPL Sense generates one.

After several wrong API keys, the L1 blocks the connection for 30 seconds.

Setting up the L1 itself

When an L1 is connected via USB, you set it up under Settings › Leveler:

• Device Information: type, serial number, firmware, MAC addresses
• Ethernet Configuration: automatic or static with IP address, netmask and gateway
• WiFi Configuration: network and password. The L1 only supports 2.4 GHz networks. The status shows the connection and signal strength.
• Network API: hostname, API key (empty: leveling over the network off; Generate creates one), admin password for the L1’s web interface and the encryption (Off, Self-signed certificate, Custom certificate)

Limits and mode do not belong here but in the measurement’s leveler settings.

Modes

Background on audience compensation: Audience noise.

Limits

Under Limit Values you enter a limit between 40 and 140 dB for each of A, C and Z. An empty field means: this weighting is not controlled. If several limits are set, the weighting that requires the greatest reduction applies; it is called dominant.

The leveler controls to an average over about 10 seconds. The gain reduction is at most 40 dB.

Calibrating the line offset

Only for the mode with audience compensation. The line offset is the difference between the level at the sensor and the line level when only the sound system is playing. Before calibrating, the measurement must be active and stopped, the sensor connected and the leveler mode saved or applied (Apply settings).

1. Play pink noise through the entire signal chain, as loud as during the event. If a DJ mixer is the source, feed the noise into the DJ mixer.
2. Make sure it is quiet: no audience, no conversations, no other sources.
3. Click Capture Line Offset. SPL Sense measures for three seconds and enters the line offset for A, C and Z.
4. Check the Correlation: it should be as close as possible to 1.000 for all weightings. Otherwise repeat the measurement.
5. Save.

You can also change the line offset manually. Be careful: even a small deviation causes the leveler to ignore audience noise or to intervene too strongly.

Reading the correlation

The correlation compares the measured level with the level the sound system alone should produce.

During the measurement

When the measurement is running and the leveler is active, the live strip shows:

• the current Gain Reduction
• the Correlation per weighting; the dominant one is bold and marked with >, for example > 0.987 @A
• the 1-second level of the dominant weighting highlighted

You can change limits, mode and line offsets during the measurement as well; they apply immediately without the gain reduction jumping. Calibrating is only possible with the measurement stopped.

The day chart additionally shows the line level, the gain reduction and the correlation. With the cloud uplink, this data also goes to SPL Cloud.

Warnings

Bypass

Bypass Leveler switches the control off immediately, for example in case of a problem. Caution: the volume then rises by the current gain reduction. With 15 dB reduction, it suddenly gets 15 dB louder.

The bypass applies to the whole device and stays on until you lift it with Reenable Leveler, even across a restart, a change of measurement or unplugging and replugging. As long as it is active, the overview and the measurement page show a notice.

Stop and interruption

• Stop: the leveler sets the gain reduction to 0 and releases control. SPL Sense warns when stopping if the leveler is currently reducing.
• Interrupted (sensor gone): the last gain reduction remains until the sensor delivers data again.

Who can change what

The leveler settings can be changed for every open measurement, even without a sensor and even when it is not active. Not for a completed measurement. From SPL Cloud, mode, limits and line offsets can be changed via remote control, but not the connection or the calibration.

8 - Sensor and calibration

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.

Calibration status

If the calibration has expired or is invalid, SPL Sense asks for confirmation when starting the measurement (Start anyway). If the measurement is started via autonomous mode, the API or remote control, SPL Sense does not ask.

Weather protection filter

A weather protection over the microphone slightly changes the frequency response. The compensation filter corrects this. It must match the weather protection used:

• Enable Filter for SPL Tools W1 for the SPL Tools W1 weather protection
• Enable Filter for Weather Protection V1 for the older V1 weather protection
• Disable Filter without weather protection

The filter is stored in the sensor and applies until you change it, also for other measurements and on other computers. You can only change it when no measurement is running. When it is switched on, the overview shows a notice and the measurement data is marked.

Calibrating the sensor

With an authorization as a calibrator, you can calibrate sensors yourself. You need:

• SPL Sense for Windows or macOS (not available in web server mode)
• internet
• a sound calibrator with 94 or 114 dB
• a confirmation as a calibrator from SPL Tools (see below)

Applying as a calibrator

1. On the sensor page, Calibrate › Apply as Calibrator.
2. Fill in the online form. In it, you also describe your calibration equipment.
3. SPL Tools reviews your application and confirms it by email.

As soon as you have the confirmation, you can calibrate.

Procedure

The measurement must be stopped and the sensor connected.

1. Sensor page › Calibrate › Log In. SPL Sense shows who you are logged in as and the current calibration.

2. Put the running calibrator on the sensor and wait until the level is stable.

3. Click the capture button for 94 dB or 114 dB, matching your calibrator.

4. Check the Capture Result:

   • Capture drift: fluctuation during the capture
   • Previous calibration drift: how far the sensor deviates since the last calibration

   If the values indicate that the sensor is drifting, SPL Sense warns you. Calibrate again and check the sensor for mechanical damage; if in doubt, send it in for inspection.

5. Choose the Signing Organization and the certificate, and fill in Calibrated For and Calibrator Device.

6. Click Sign and Store Calibration.

The calibration is digitally signed and stored in the sensor. From now on, the measurement data is signed with the new calibration.

A sensor without a previous calibration cannot be calibrated this way. In that case, contact SPL Tools.

9 - Autonomous mode

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

1. Settings › Autonomous Mode.
2. Set Automatically run a measurement when running to On.
3. Choose the Measurement. Only open measurements are offered.
4. 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:

• an operator PIN, so that nobody changes the settings
• the live screen in kiosk mode as a display
• the cloud uplink, so you can see the measurement remotely, and with Pro alarms in case the measurement fails

10 - Settings

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

Operator PIN

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

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

With a PIN set:

• all pages except the live screen are locked. SPL Sense shows SPL Sense is locked and asks for the PIN.
• SPL Sense also asks for the PIN when leaving the live screen and full screen.
• the PIN applies in the app and in the browser (web server mode).

Remove PIN lifts the protection again.

SPL Cloud

Under Settings › Cloud you connect SPL Sense with SPL Cloud. A registered installation is called an instance in the cloud.

Registering

1. Register instance. SPL Sense needs internet for this.
2. Open the link shown or scan the QR code with another device. The code is only valid for a short time; Get new code gives you a new one.
3. Log in to SPL Cloud and confirm the registration. Choose the Owner: you personally or an organization you are a member of. See Organizations.

The page then shows Instance is registred with instance ID, host, owner and the connection status (Online, Connecting…, Offline).

Which measurements go to the cloud is set per measurement with the Cloud Uplink, see Measurements.

Unregistering

Unregister Instance disconnects SPL Sense from the cloud. The cloud uplink is switched off for all measurements; what is already in the cloud stays there. After registering again, you switch the uplink back on per measurement.

If the page shows Authentication failed!, unregister the instance and register it again.

Allowing remote control

With Allow remote control, people with access to this instance in SPL Cloud may start and stop, switch and create measurements and change offsets, leveler and value profile, as long as SPL Sense is online. Calibration and updates are never possible remotely.

Remote control is off by default. When it is on, the status bar shows this, and every command from the cloud appears as a message and in the measurement’s events, with the name of the person.

In the cloud, remote control requires SPL Cloud Pro on the measurement.

API

The SPL Sense API lets you monitor and control SPL Sense and connect external audio processors as levelers. It is off by default. Details under SPL Sense API.

Language

German, English, French or System Default.

About

Version, release notes (English), contact, privacy policy and the open source licenses used.