What Is Frequency Response?

Frequency response describes how an audio system reproduces or amplifies frequencies across the audible spectrum (20 Hz – 20 kHz). A system with a “flat” frequency response reproduces all frequencies with equal intensity, while one with peaks or dips results in colored or unbalanced sound.

It is graphically represented through a frequency spectrum where:

• The X-axis shows frequencies (Hz).
• The Y-axis shows sound pressure levels (dB).

Practical Example:

A Tecnare speaker such as the IBZA10, designed for full-range applications, offers a frequency response from 45 Hz to 18 kHz, ensuring clear and detailed sound for vocal and instrumental applications.

Factors Affecting Frequency Response

Speaker Design:

• Full-range speakers, like the IBZA Series, tend to provide a more uniform response across the spectrum.
• Subwoofers from the SW Series focus on low frequencies, generally below 120 Hz.

Interaction with the Environment:

• Reflections from walls, floors, and ceilings can cause peaks and dips at certain frequencies due to phenomena like comb filtering.
• Small spaces with hard surfaces often amplify mid and high frequencies, while large spaces may absorb low frequencies.

Signal Processing:

• Tools like equalizers and DSP processors enable adjustments to the frequency response.
• For instance, Tecnare’s TDAP Series amplifiers provide parametric equalization to correct acoustic anomalies in real time.

How to Measure Frequency Response

To analyze a system’s frequency response:

• Use measurement microphones: These are designed to capture sound without altering frequencies.
• Analysis software: Programs like Smaart or EASE Focus help visualize the frequency spectrum.
• RTA (Real-Time Analyzer): This tool displays how frequencies behave during the playback of a test signal, such as pink noise.

Optimizing Frequency Response

Equalization

EQ is the primary tool for adjusting frequency response:

• Cutting problematic frequencies: Attenuating specific bands that cause feedback or resonances.
• Boosting desired frequencies: Enhancing frequencies that improve clarity or sound impact.

Practical Example:

In a line array system like the CLa21PLUS, the DSP in a T Series amplifier can attenuate frequencies between 200–400 Hz to eliminate a “boxy” sound in vocals.

Directivity Control

Systems like the Array Series are designed to control sound dispersion, minimizing unwanted reflections and focusing acoustic energy on the audience area.

Practical Example:

In a theater, the CLa21PLUS modules can be configured to limit vertical dispersion, avoiding reflections off the ceiling and enhancing speech intelligibility.

Acoustic Treatment

Optimizing the environment is as crucial as fine-tuning the equipment:

• Install acoustic panels to absorb mid and high frequencies.
• Use bass traps in corners to control low-frequency build-up.

Case Study: Frequency Response Setup for an Auditorium

Scenario:

A Tecnare system with IBZA Series speakers for main coverage and SW Series subwoofers for low-frequency support is installed.

Steps:

1) Initial Analysis:

Use pink noise and an RTA to identify peaks and dips in the frequency response.

2) Equalization:

Attenuate midrange peaks (800–1,000 Hz) that cause listener fatigue.
Enhance low frequencies (60–120 Hz) to add impact to orchestral music.

3) Directivity Optimization:

Adjust speaker coverage through simulations in EASE Focus to avoid acoustic shadow zones.

4) Final Testing:

Evaluate the system with live music and speech, ensuring all frequencies are reproduced evenly.

Conclusion

Frequency response is a cornerstone of sound system design. Understanding how speakers, the environment, and signal processing interact allows sound engineers to achieve an optimal auditory experience for their audience.

If you have projects that require acoustic adjustments or the installation of high-precision systems, contact us. Our team of engineers is ready to provide advanced acoustic consulting and simulations.