An Outdoor Ecler Sound System for Autocross Racing

The venue: an amphitheatre carved for autocross

CROSS Arena Přerov, also known as Přerov Gorge or the Valley of the Mammoths, is one of the Czech Republic's best-known natural autocross circuits. It regularly hosts rounds of the FIA European Autocross Championship and is known for demanding terrain, including an elevation difference of approximately 42 metres and its characteristic Mamut jump.

The natural amphitheatre gives spectators wide views of the circuit, but its size and topography, combined with high motorsport noise levels, create a demanding environment for professional audio.

To meet these conditions, Czech AV specialist MusicData designed a new sound reinforcement system using Ecler eCMP12 outdoor loudspeakers, an Ecler ALMA24 digital loudspeaker manager, and Ecler HADA Series DSP amplifiers. The objective: intelligible race commentary throughout the spectator areas, with consistent coverage and accurate time alignment.

The challenge: intelligibility in a high-noise, large-scale outdoor environment

At an autocross event, a PA system competes with a constantly changing acoustic environment dominated by high-powered racing engines. Raising sound pressure level alone does not solve this. Commentary has to stay intelligible across the venue without creating excessive overlap between coverage areas or audible delayed sound for spectators positioned between different parts of the system.

The geometry of CROSS Arena Přerov adds a further layer of complexity: the circuit extends across a natural amphitheatre with significant elevation changes, while spectator areas spread around a large section of the track.

Key system requirements:

●       Consistent audio coverage across the spectator areas

●       High speech intelligibility in a high-noise environment

●       Accurate time alignment between geographically separated loudspeaker zones

●       Reliable outdoor operation throughout the racing season

Eight audio zones, fourteen eCMP12 loudspeakers

The system was divided into eight independent audio zones using fourteen Ecler eCMP12 loudspeakers positioned around the circuit. Instead of treating the venue as a single distributed loudspeaker line, MusicData designed independently managed zones, which made it possible to compensate for the different distances between loudspeakers and listening areas.

The relevant variable here was not whether the system used low- or high-impedance distribution, but when the sound from each loudspeaker reached the audience. At a venue of this scale, spectators can hear more than one loudspeaker from different locations; without correct processing, differences in propagation time produce audible delayed sound and reduce intelligibility.

Digital signal processing was used to apply the required delays and align the eight zones. The result is a distributed system where the different coverage areas work together, helping commentary stay clear as spectators move around the circuit.

eCMP12: an outdoor loudspeaker built for exposed installations

Loudspeaker selection had to account for the venue's environmental conditions. The Ecler eCMP12 is a two-way music projector designed for outdoor installation, with an IP56-rated enclosure for exposed applications. Its 12-inch low-frequency driver and 1.7-inch coaxial high-frequency driver deliver 300 W RMS at 8Ω.

With a maximum SPL specified at 125 dB continuous and 131 dB peak, the eCMP12 provides the output headroom required for applications where audio needs to remain intelligible against significant background noise. Its 70/100 V transformer and 8Ω operating option give system designers flexibility when defining the amplification and distribution architecture.

Fourteen units were deployed across the eight audio zones at CROSS Arena Přerov to cover the different spectator areas around the circuit.

DSP at the centre of the system

Processing accuracy was central to the project. The system combines an Ecler ALMA24 digital loudspeaker manager with Ecler HADA Series networkable DSP amplifiers.

ALMA24 provides 2 audio inputs and 4 outputs with 24-bit/48 kHz DSP processing, including equalisation, crossover filters, dynamics processing, and adjustable input and output delays. The HADA Series adds amplification with onboard DSP and network-based configuration, covering signal routing, equalisation, dynamics, and delay management.

Combining these two processing layers allowed MusicData to adapt the system to the physical layout of the arena and apply the timing adjustments needed across widely separated loudspeaker zones, which was central to maintaining speech intelligibility over long distances.

Extending coverage to the paddock

The main spectator areas were not the only space that needed audio. The paddock and service area is located approximately 200 metres from the main circuit, which made a conventional cable connection impractical.

MusicData implemented a wireless audio link to carry the programme signal to the paddock, so mechanics, drivers, and racing teams received the same commentary and event information as spectators around the circuit. According to the system integrator, the wireless link operated without interruptions throughout the event; this is the integrator's own account and has not been independently verified by Ecler.

Result: a coherent listening experience across a demanding circuit

At a motorsport venue, professional audio functions as part of the event's operational infrastructure, not only as background sound. Commentary, results, and safety information need to reach spectators clearly despite high ambient noise, long distances, and outdoor conditions.

At CROSS Arena Přerov, the combination of Ecler eCMP12 outdoor loudspeakers, ALMA24 processing, and HADA Series DSP amplification allowed MusicData to build an eight-zone system designed around the acoustic and geographic characteristics of the circuit. Fourteen loudspeakers distributed around the venue provide the required coverage, while DSP-based time alignment supports a coherent listening experience across the different spectator areas.

The event closed with the traditional winners' ceremony, ending with the Spanish national anthem, played through the same Ecler system that had carried the day's commentary, a fitting detail given the manufacturer's Barcelona origin.

Frequently Asked Questions

What loudspeakers does Ecler use for outdoor motorsport venues?

At CROSS Arena Přerov, MusicData installed fourteen Ecler eCMP12 units, a two-way outdoor music projector with an IP56-rated enclosure and 300 W RMS at 8Ω, across eight independent audio zones.

How many audio zones cover CROSS Arena Přerov?

The venue is covered by eight independent audio zones, allowing the system integrator to compensate for the different distances between loudspeakers and spectator areas.

What DSP equipment manages the system?

An Ecler ALMA24 digital loudspeaker manager (2 inputs, 4 outputs, 24-bit/48 kHz processing) works together with Ecler HADA Series networkable DSP amplifiers to handle equalisation, dynamics, and delay alignment across zones.

How is the paddock area covered, given the distance from the main circuit?

The paddock is located approximately 200 metres from the main circuit. MusicData used a wireless audio link to deliver the programme signal there instead of a cable connection.