Loudspeaker Measurement with Clio system

CLIO Pocket – Summary The CLIO Pocket measurement system is fully sufficient for designing a passive two-way loudspeaker such as the Inn Mk II using an Accuton midwoofer and a Mundorf AMT tweeter. It provides all essential measurements, including impedance (Fs, bass reflex tuning Fb, Zobel and baffle-step effects), quasi-anechoic frequency response (on- and off-axis with time gating), and phase/timing analysis needed to verify crossover integration and stepped-baffle alignment. While CLIO Pocket does not offer full anechoic conditions or very low-frequency distortion analysis, these limitations are irrelevant for serious DIY loudspeaker development. With correct setup and careful interpretation of the data, CLIO Pocket enables precise crossover tuning and reliable optimisation of cabinet and port design, making it an ideal tool for high-quality DIY loudspeaker projects.

Using CLIO Pocket for DIY Loudspeaker Design

The CLIO Pocket measurement system is absolutely sufficient for this project.
In fact, for a passive two-way loudspeaker design such as the Inn Mk II (Accuton midwoofer + Mundorf AMT), CLIO Pocket is practically ideal.

What CLIO Pocket can do (and that is exactly what is needed)

✅ Impedance measurements (essential)

  • Resonance frequency (Fs) of the Accuton driver

  • Bass reflex tuning frequency (Fb)
    (identified by the two impedance peaks with the dip in between)

  • Effect of Zobel networks and baffle step compensation (BSC)

  • Minimum system impedance of the complete loudspeaker

👉 This is arguably the most important measurement in the entire design process, and CLIO Pocket performs it very accurately.

✅ Frequency response measurements (quasi-anechoic)

  • On-axis response (1 m)

  • Off-axis response (±15°, ±30°, ±45°)

  • Time-gated measurements to suppress room reflections

👉 Perfect for fine-tuning the crossover in the 2.1–2.3 kHz region.

✅ Phase and timing analysis

  • Relative phase alignment between woofer and tweeter

  • Detection of lobing around the crossover frequency

  • Verification that the stepped baffle provides the intended acoustic alignment

What CLIO Pocket cannot do (and why this is not a problem)

❌ Extremely low-frequency distortion measurements below ~100 Hz
❌ Fully anechoic measurements (not realistic in a home environment anyway)
❌ The higher degree of automation found in large CLIO FW systems

➡️ For DIY and semi-professional loudspeaker development, these limitations are not relevant.

Recommended practical setup

Microphone

Preferably use:

  • CLIO MIC-01 or MIC-02, or

  • another supported, calibrated measurement microphone

Position:

  • Distance: 1 meter

  • On the acoustic axis (usually slightly biased toward the tweeter)

Measurement environment

  • Measure at listening height

  • Place the loudspeaker at least 1 meter away from walls

  • Set the time gate so the first room reflection falls outside the window
    (typically 4–6 ms, depending on the room)

Recommended measurement sequence (efficient workflow)

  1. Measure impedance of the Accuton driver alone (mounted in cabinet, bass reflex open)

  2. Trim the port length to achieve the target Fb

  3. Measure frequency response of the Accuton alone (gated)

  4. Measure frequency response of the AMT alone (with a protective series capacitor)

  5. Measure the complete system with crossover (on- and off-axis)

  6. Apply small crossover refinements

All of this can be done comfortably with CLIO Pocket.

Conclusion

  • Yes, CLIO Pocket is more than sufficient

  • There is no need to upgrade to a larger CLIO system

  • The limiting factor is not the hardware, but how well the measurement data is interpreted

Once the first measurements are available, the data can be used to:

  • interpret frequency and impedance curves,

  • identify which crossover components should be adjusted first,

  • and fine-tune the system toward the desired sonic signature.

This project is perfectly suited to CLIO Pocket-based development.