Room acoustic criteria
Room acoustic criteria: Making the invisible measurable
Why is a speaker sometimes crystal clear in one hall, while in another their words are lost in a diffuse "sound mush"? To objectively evaluate such subjective impressions, acoustics uses specific measurement parameters.
The spatial impulse response:
It forms the basis of almost all criteria and functions as an acoustic fingerprint of a position in space. It is recorded by exciting the room with a short impulse (e.g., a bang) in order to measure the intensity and timing of arriving reflections.
Key criteria at a glance
1. Clarity level (C 50 )
This measure assesses speech intelligibility at a specific location. It relates the energy of direct sound and early reflections to the late reverberation.
The HSA3 advantage: By selectively damping disruptive late reflections without creating a "dead" acoustic environment, the HSA3 significantly improves intelligibility. Thanks to its micro-perforation, it can be precisely tuned to speech frequencies.
2. RASTI (Rapid Speech Transmission Index)
A standard measurement for sound reinforcement systems that also takes into account external noise (e.g. railway tracks or ventilation systems).
3. Clarity measure (C 80 )
It assesses the transparency of music. It determines whether the instruments of an orchestra are clearly distinguishable or blend together sonically.
4. Side-to-side sound pressure level and bass ratio
These values define the emotional experience in the space:
- Side sound dispersion: Creates a feeling of "envelopment". You feel surrounded by the sound, instead of only perceiving it from the front.
- Bass ratio: Describes the sonic "warmth". Too low a value often makes rooms sound sterile or shrill.
Precision instead of compromise: Why HSA3 makes the difference
Conventional absorbers, such as thick fabrics, often dampen frequencies in an uncontrolled manner – strongly in the high frequencies, hardly at all in the bass. This impairs the bass response and leads to a muffled sound.
The HSA3 functions as a high-precision tool:
- Targeted control: Mathematical microperforation allows for the precise determination of absorption frequencies to optimize clarity and definition without losing heat.
- Optimal positioning: It resolves the conflict between acoustically necessary placement and appearance through discreet or transparent designs (e.g. on glass fronts or exposed concrete).
The result is natural acoustics that, beyond meeting the requirements of DIN 18041, create a pleasant feeling of space.