If you use Rational Acoustics Smaart for system measurement and tuning, the choice of audio interface is crucial.
Below is a ranked comparison of the most widely used and reliable interfaces for Smaart, covering everything from compact two-channel models to larger multichannel rigs.
Audient EVO 4 – Best Compact Interface for Smaart
Inputs/Outputs: 2 in / 2 out (USB-C)
Features: Phantom power, gain tracking, Smaart integration
Best for: Portable rigs or single-mic measurements
Verdict: Excellent driver stability, compact design and full Smaart compatibility make it the top overall choice for most users.
Focusrite Scarlett 18i16 (4th Gen) – Multichannel Option
Inputs/Outputs: 18 in / 16 out
Features: Reliable drivers, large I/O count, flexible routing
Best for: Theatres, system integrators, and users with several measurement microphones
Verdict: Professional-grade flexibility without a huge price tag.
Steinberg UR22C – Reliable Entry-Level Choice
Inputs/Outputs: 2 in / 2 out
Features: Metal housing, clean preamps, stable macOS/Windows drivers
Best for: Education, small FOH measurement, or backup rigs
Verdict: Well-built, simple and dependable.
Audient iD4 Mk II – Compact with Premium Preamps
Inputs/Outputs: 2 in / 2 out
Features: Audient console-grade preamps, phantom power
Best for: Users who want higher preamp quality in a small box
Verdict: Great sound and solid construction for its size and cost.
Universal Audio Volt 2 – Premium Small Interface
Inputs/Outputs: 2 in / 2 out
Features: “Vintage” analog coloration mode, solid build, stable drivers
Best for: Studio or hybrid users who also use Smaart for calibration
Verdict: Professional design, simple operation and reliable performance.
Behringer UMC202HD – Budget Option
Inputs/Outputs: 2 in / 2 out
Features: 48 V phantom power, USB bus powered
Best for: Students, training, and basic measurement setups
Verdict: Inexpensive, functional and adequate for simple two-channel Smaart work.
Audient EVO 8 – Four-Channel Upgrade over the EVO 4
Inputs/Outputs: 4 in / 4 out
Features: Smaart gain tracking, compact form, USB-C
Best for: Mid-size measurement rigs or multi-mic setups
Verdict: Same workflow as EVO 4, with more flexibility and headroom.
How These Interfaces Were Ranked
Ranking is based on:
- Driver stability and operating-system support
- Quality of microphone preamps and phantom power
- Gain-tracking or calibration stability with Smaart
- Input/output flexibility
- Price versus performance
References include Rational Acoustics’ official support documentation and user feedback from professional audio forums.
Recommendations by Use Case
| Use Case | Recommended Interface | Reason |
|---|---|---|
| Portable / single mic | Audient EVO 4 | Compact and fully Smaart-compatible |
| Multi-mic / venue | Focusrite Scarlett 18i16 | Many inputs and stable drivers |
| Education / budget | Behringer UMC202HD | Low cost and simple setup |
| Studio calibration | Universal Audio Volt 2 | High quality and quiet operation |
| Medium rigs | Audient EVO 8 | More I/O without going rackmount, fully Smaart-compatible |
| Legacy systems | Roland Octa-Capture | Proven stability and long support life, fully Smaart-compatible, discontinued / 2nd hand |
Key Considerations Before You Buy
- Phantom power is required for most measurement microphones (e.g. iSEMcon, MELLab, Earthworks).
- Dual-channel FFT measurements need at least two inputs: one measurement mic and one reference signal.
- Avoid USB hubs or extenders; connect interfaces directly to the computer.
- For networked or large multichannel systems, consider Dante Virtual Soundcard or similar solutions.
- Choose an interface with more channels than you currently need to allow for expansion.
Conclusion
For most engineers, the Audient EVO 4 or Focusrite Scarlett 18i16 offer the best balance of price, stability, and Smaart functionality. However, currently only the Audient EVO series offers Smaart GUI integration & gain tracking.
The summary was created by an AI service from ChatGPT. The content has been quality-checked by TZ AUDIO before publication.