The key acoustic technical indicators for listening rooms and recording studios include reverberation time and sound field uniformity. Meanwhile, the background noise shall be controlled within an appropriate range to meet regular operation requirements.

For conventional listening rooms, only the mid-frequency reverberation time needs to meet specified criteria during design. High-performance listening studios impose strict requirements on the frequency characteristics of reverberation time, which should be kept as flat as possible. The sound absorption coefficient curves of ordinary sound-absorbing materials or structures vary drastically with frequency, especially exhibiting weak absorption at low frequencies. In addition, listening rooms and recording studios are typically small acoustic spaces, so the control of room acoustic modes is critical. Accordingly, various types of sound-absorbing structures are required for listening rooms and recording studios to adjust reverberation time across different frequency bands. Low-frequency traps are a widely adopted low-frequency absorption solution.

Furthermore, research demands of modern artificial intelligence and multimedia technologies require listening rooms to feature adjustable reverberation time, so as to evaluate product performance under diverse real environments (e.g., communication headsets and vehicle cabin acoustic quality).

During the design and construction of listening rooms and recording studios, we have independently developed multiple sound-absorbing structures including W100, FAA, FLA and EVA to satisfy precise reverberation time frequency response and adjustable reverberation performance requirements.

FAA Flip Adjustable Absorber

The FAA is an open-and-close absorptive structure composed of two basic units. When unfolded, its top surface acts as the sound-absorbing surface, while the side and back surfaces function as reflective surfaces. When folded, all top, bottom and side surfaces become reflective. The two FAA units are connected by hinges; rotating one unit over the other via the hinge switches the absorber from unfolded to folded state, forming an entirely reflective outer surface.

The sound absorption performance of FAA varies with its absorptive area in open/closed states. By adjusting the number of FAA units opened or closed inside an acoustic space, the reverberation time of the space can be regulated.

The FAA has a base thickness of 100 mm when unfolded, with perforated protective panels on the surface and eco-friendly sound-absorbing filling inside. Thus, the unfolded FAA delivers sound absorption performance comparable to the W100 structure. Even in folded state, its reflective outer housing retains limited low-frequency absorption capacity. Optimizing the material parameters of the outer shell suppresses room acoustic modes and improves low-frequency acoustic performance of the space.

FLA Flip Low-Frequency Absorber

The FLA adopts an open-and-close structure similar to FAA, dedicated to low-frequency sound absorption below 100 Hz. Each FLA basic unit consists of four resonant absorbers, realizing effective sound absorption within the 60 Hz–100 Hz frequency band.

Toggling the FLA between open and closed states adjusts low-frequency absorption performance under 100 Hz. When used in conjunction with FAA, the FLA further expands the adjustable frequency range of flip-type absorbers and modifies the low-frequency modal characteristics of the room.

The FLA features a base thickness of 100 mm, with multiple configurable combinations of internal resonant absorbers whose parameters are customized according to on-site space conditions.

EVA Electric Variable Absorber

The EVA is an electrically driven automatically adjustable sound-absorbing structure. Its surface adopts slotted construction, consisting of fixed outer slotted panels and internally motorized adjustable plates. The slit width can be continuously adjusted from 0 mm to 50 mm, enabling continuous modulation of sound absorption performance.

The EVA has a base thickness of 200 mm, comprising electric drive mechanisms and sound-absorbing materials inside. The driving components of each EVA unit can be interconnected and controlled uniformly via a PID control panel.

Listening rooms and recording studios generally belong to small acoustic enclosures, where room geometric dimensions exert a profound influence on the internal sound field. In our listening room design, we optimize room geometry based on room acoustic principles, and deploy the aforementioned low-frequency absorbers to suppress low-frequency modes, delivering optimal subjective listening experience.

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