Trial Starting Modes: Every Way to Start a Timed Trial with the SplitFast Timing Hub

From the built-in starter audio to wired guns, pressure switches and sound detection — how the SplitFast Timing Hub starts trials, catches false starts and measures athlete reaction times.

For almost every trial — training sessions and race days alike — the Timing Hub’s built-in starter audio is the best way to start: consistent, accurately timed starts with nothing more than a speaker plugged into the Hub. But some programs need to start trials another way, whether that’s a start device they already own, a start triggered by the athlete’s own movement, or a reaction-time session with a single athlete on the blocks.

The 2nd generation SplitFast Timing Hub includes an external trigger interface and an audio detection microphone that can be used with external start devices and sensors. This gives you multiple options for starting trials, detecting false starts and measuring athlete reaction times. This guide walks through each starting mode and when to use it.

Wireless Start Signals

Out of the box, the Timing Hub starts a trial in one of two wireless ways:

• Built-in starter audio: The Hub plays the start sound through an external speaker connected via 3.5mm audio cable, and the trial starts with it.
• Wireless timing gate start: In Flying Start, Lap and Shuttle training modes, a wireless timing gate starts the trial the moment the athlete crosses the LiDAR sensor. The athlete simply runs — there is no start signal to react to.

These two options cover everything — training sessions and race days alike. The wired options below aren’t upgrades; they are there for customers who need to start trials some other way, such as with start equipment they already own, from the athlete’s own movement, or to detect false starts and measure reaction times.

Wired Start Signals

The Hub’s wired trigger interface gives you additional options for starting a trial, detecting false starts and measuring athlete reaction times.

Wired starter / gun

Any start device or gun with a contact closure or low voltage output can be connected to the SplitFast Timing Hub. The trial starts the instant the external device triggers — so if you already own a start gun or electronic starter and want to keep using it, you can.

Pressure switch

A pressure switch plate that the athlete holds down at the start line can be used to trigger the start as soon as they release the switch. Timing begins with the athlete’s first movement rather than a start signal, so it is a great way to measure reaction time, or eliminate the reaction component from a trial.

Athlete motion sensor

A wired IR motion sensor at the start line can be used to start the trial. It can be set to start when the athlete breaks the beam or when they clear the beam, so you can choose the trigger point that suits your start position and drill.

Start Sound Detection

Not every start device has an electronic output — and it doesn’t need one. The Hub’s internal microphone can detect a start sound via audio alone, such as a clapper or a start gun with no electronic output. Once the system is Set, the trial begins as soon as the sound is detected.

False Start Detection

The external trigger interface can also be used to signal a false start, in either of two ways:

• Official’s pushbutton: A wired pushbutton activated by a start official signals the false start manually.
• Motion sensor across the track: A single wired motion sensor looking across all lanes of the track at the start line will detect any athlete in any lane false starting.

Measuring Athlete Reaction Times

Reaction time is a part of the sprint start you can't assess by eye — and the Timing Hub can measure it directly. Combine a wired motion sensor or pressure switch with the Hub’s audio start, and the system measures the delay from when the start sound is played to when the athlete moves. Reaction time measurement is available in training modes when timing a single athlete.

When measuring reaction time, the system will also signal a false start if the athlete moves less than 100 milliseconds after the start gun — the same reaction threshold used to judge false starts in official competition.

Starting Modes at a Glance

Which Starting Mode Should You Use?

• For all trials — training and races: The built-in starter audio is the best option. All it needs is an external speaker connected to the Hub, and it gives consistent, accurately timed starts every trial.
• Flying sprints, laps and shuttles: Let the wireless timing gate start the trial as the athlete crosses the LiDAR sensor.
• Already own a start device? Connect it via the wired trigger interface, or use start sound detection if it has no electronic output.
• Athlete-initiated starts: Use a pressure switch or motion sensor so timing begins with the athlete’s own movement.
• Reaction time work: Pair a motion sensor or pressure switch with the Hub’s audio start to measure reaction times — with automatic false start detection under 100 milliseconds.

Related Reading

If you’re setting up starts with the SplitFast Timing Hub, you may also find these resources useful:

• Eliminating Starting Speaker Delay (video) — Calibrate the Timing Hub to remove start speaker delay
• Timing System Video Tutorials — Step-by-step series from unboxing to reviewing splits
• Portable LiDAR Athletics Timing System — How wireless timing gates work in real training environments
• How to Measure Sprint Time Accurately — Electronic timing methods and best practices