Smaart input calibration is primarily for accurate Sound Pressure Level (SPL) measurements. It establishes the sensitivity of your measurement chain (microphone + preamp + audio interface) by correlating a known level from an acoustic calibrator to the digital signal level in Smaart. This is essential for reliable SPL, Leq, and exposure logging.
Prerequisites
A measurement microphone connected to your audio interface.
An acoustic calibrator (e.g., producing 94 dB or 114 dB at 1 kHz; 114 dB is often preferred for more headroom in loud environments).
Appropriate adapter for your mic to ensure a snug fit. Most calibrators are made for 1/2″ microphones, so you need an adapter reducing the diameter to 1/2″ | 7mm for a proper Smaart input calibration.
Audio interface gains set appropriately (do not change gains after calibration unless your interface supports gain tracking).
Step-by-Step Procedure for Smaart input calibration
Open I-O Config:
Go to Config > I-O Config (or use shortcut: Ctrl/Cmd + I).
Select the Input Channel:
In the Input tab, check “Use” for your audio device.
Highlight the channel connected to your measurement microphone.
Optionally, assign a “Friendly Name” (e.g., “FOH Mic”).
Open Amplitude Calibration:
Click the Calibrate button at the bottom (or double-click the channel row).
Prepare the Calibrator:
Fit the calibrator snugly over the microphone (slowly to avoid pressure damage).
Turn on the calibrator and note its output level (usually 94 dB, 110dB or 114 dB).
Adjust Input Gain for Headroom:
Monitor Smaart’s signal meter for the channel.
Set preamp gain so the signal peaks around -12 to -6 dBFS (green-to-yellow transition) — this provides headroom for peaks up to 130–140 dB SPL without clipping.
Run Calibration:
In the Amplitude Calibration window, confirm the correct device/channel is selected.
Click Calibrate.
Smaart measures the incoming level (progress bar reaches 100%).
Enter the calibrator’s exact output level (e.g., 114 dB) if prompted, or confirm it.
Click Apply / OK. Smaart calculates and applies an offset (visible in the “Cal. Offset” column).
Verify and Close:
Check the signal meter or SPL display — it should now read close to the calibrator’s level.
Remove the calibrator.
Close windows and start measurements.
You have finished your Smaart input calibration
A Real-World Perspective on Calibrators for Live Sound Measurements
Acoustic calibrators come in many shapes, sizes, and standards, designed for a wide range of applications. Here’s the good news for us live sound engineers: our needs are relatively straightforward. We don’t require high-end, laboratory-grade calibrators that meet the strictest standards. A simple, reliable model like the iSEMcon SC-1 or the AZ 8930 is more than sufficient for in-field verification—ensuring your measurement chain is consistent before a gig or system tune.
The catch? If you’re ever in a situation where documentation matters (e.g., legal disputes, compliance audits, or client requirements), you’ll need a valid calibration certificate—typically no older than one year. Renewing that certificate means sending the unit to an accredited test house or the manufacturer.
Factor in 3–6 weeks (or longer) for shipping both ways, processing, and return—plus customs handling, calibration fees, and potential repairs—and you’re easily looking at €50–€80 or more. That’s often approaching (or exceeding) the price of a brand-new basic calibrator from reputable Far East manufacturers.
That’s why we’ve chosen to stock models like the AZ 8930: high-quality, affordable, and purpose-built for live sound work. In most cases, buying a new one is simply cheaper, faster, and more practical than recalibrating an older unit. You get fresh performance, no downtime, and peace of mind without the hassle.
We source our AZ 8930 from reliable European partners who ensure fast availability—even handling direct fulfilment when needed—so you always get a fresh, ready-to-use unit without delays.
If compliance-grade certification is critical for your workflow, we can always discuss options—just get in touch!
Tips and Best Practices for Smaart input calibration
Headroom: Setting the calibrator at the highest level helps high levels during a concert having re-adjust your measurement gained so having to re-calibrating. All this is easier when you use a sound-card allowing the gain tracking option.
Multiple Channels: Repeat for each mic input. You can stay in the calibration “window” for this and just change the input channel from there.
Gain Changes: Avoid adjusting preamp gain post-calibration (breaks accuracy). Some interfaces (e.g., Rational Acoustics Smaart I-O*, Roland Octacapture*, Audient EVO 4, EVO8 and EVO 16) support gain tracking. *discontinued – only available 2nd hand or some very old stock
No Calibrator?: You can manually enter an offset, but it’s inaccurate — not recommended for compliance or critical work.
Mic Correction Curves: Separate from SPL calibration; import these for frequency response flattening (via I-O Config > Mic Correction column). Microphone manufacturers like iSEMcon and MELLab supply frequency response curves in digital format. Smaart then applies an internal correction to normalise the microphones frequency response. So the term correction curve can be a little misleading. But hey … we are smart, aren’t we 😉
For transfer function or RTA, precise SPL calibration isn’t always needed, but good input levels prevent clipping/distortion. Ad hey – it is always nice to know how loud it actually is, isn´t it?
Smaart is excellent on its own, but most users find they get much more out of it after some structured training. That’s where our seminars come in. At TZ Audio we run practical seminars, both online and in-venue. We offer seminar-only or full “all you need packages” including software & hardware. It’s simply the fastest way to become comfortable and confident with the measuring a sound system.
If you’re in Norway, Sweden, Denmark or Iceland – or elsewhere – we offer is online seminars and traveling to Norway is a valid option too of course. We’re here if you have any questions about the software or upcoming seminars.
