NVH Testing & Appliance Noise

Semi-Anechoic Chamber

Anechoic walls and ceiling with a hard, reflective floor — the industry-standard configuration for automotive NVH, household appliance noise testing, and power tool certification.

Technical Specifications

Free-field conditionAbove 100 Hz (standard)
Floor typeReflective (concrete / steel)
NRC (walls/ceiling)≥ 0.98
Background noise≤ NC-15 (optional NC-10)
Standard complianceISO 3745 / IEC 60704
Drive-in optionYes (ramp to 4 t axle load)
Size range20 m³ – 1,000+ m³
VentilationSilenced HVAC system
CertificationCE marked

Applications

  • Automotive NVH component testing
  • Electric vehicle powertrain noise
  • Household appliance sound power (IEC 60704)
  • Power tool noise certification
  • HVAC equipment acoustic rating
  • Industrial machinery noise measurement

Overview

A semi-anechoic chamber replicates an infinite reflective half-space: the floor is solid and acoustically reflective, while walls and ceiling are lined with sound-absorbing wedges. This configuration matches real-world operating conditions for most products, which are tested on floors or mounted on surfaces in use.

HEMU Acoustics semi-anechoic chambers are widely used for ISO 3745 sound power measurements, automotive component NVH characterization, household appliance noise rating (IEC 60704), and industrial equipment certification. Available with drive-in ramps and underfloor dynamometer foundations for full vehicle testing.

The reflective floor (typically polished concrete or steel plate) enables consistent half-space measurements. Our modular system accommodates widths from 4 m to 20 m, with ceiling heights up to 8 m. Custom configurations for electric vehicle powertrain testing, including grounding provisions and high-voltage cable penetrations, are available.

Background noise levels of NC-15 or lower are achievable, ensuring compliance with the most demanding measurement standards. All chambers are delivered with a full acoustic qualification report validated to the specified standard.

Key Features

Drive-In Vehicle Access

Optional drive-in ramp rated to 4 t axle load with airtight acoustic door seal. Suitable for full car, motorcycle, and commercial vehicle testing.

Underfloor Integration

Custom underfloor pits for dynamometers, roller benches, and torque measurement systems. Structural loads calculated per EN 1990.

EV-Ready Configuration

High-voltage cable penetrations, shielded lighting, and non-sparking surface options for battery electric vehicle NVH labs.

Precision Floor Level

Polished concrete or steel plate floor with ±2 mm flatness tolerance across the full chamber footprint.

Acoustic Door System

Double-seal acoustic door with ≥45 dB insertion loss. Available in single, double, and drive-in (roll-up) configurations.

Acoustic Qualification

Delivered with ISO 3745 qualification report. Optional third-party validation by accredited laboratory available on request.

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