One Microphone or Several? Spatial Averaging Explained
Question
Is it better to move one microphone around the room, or to deploy several microphones and measure them simultaneously? Well ….
The Engineering Reality
Often misunderstood – A single microphone describes one listening position only. A system optimised for that position often performs poorly just a few metres away.
Using multiple microphones or multiple positions of that matter allows you to capture the spatial average of the system response. So when moving one microphone around you can capture as many traces as you like, but the measurements would not be simultaneously. This can be a caveat to be considered. In Smaart v9, you average thee traces in “post” so to say, or in real time using a Live Average trace across all measurement channels.
So when you then find out that a frequency deviation appears consistently across all measurement channels, it is a systemic issue and can most likely be addressed with EQ.
If it appears in only one position, it is a local effect (reflection or interference) and should be dealt with with appropriate measures like dampening the reflection, fixing loudspeaker placement and delay, and so forth.
Practical Conclusion
Spatial averaging is essential if the goal is to optimise the system for the room, not for a single seat.
In my view, this is standard practice and the main reason a systems engineer is involved at all.
The band’s sound engineer focuses on the artist and the mix. The systems engineer’s job is to make sure the sound works for the entire audience, so that everyone has a good experience — not just the people standing next to the mixing desk.
How you achieve spatial averaging is largely a question of workflow, time, and money. For this reason, the question itself cannot be answered in any universal or reassuring manner.
You may use several microphones, one microphone moved repeatedly, or a cheerful combination of wired and wireless systems — all are valid, provided you understand their limitations and do not lie to yourself afterwards.
In a perfect world, unconstrained by budgets or reality, one would of course deploy a perfectly matched octet of measurement microphones, each equipped with its own wireless adaptor. This would be elegant, efficient, and deeply satisfying.
Unfortunately, such a world requires either a generous sponsor or a lottery win, preferably both … or would it? – the MELLab MYc-3 measurement microphone matched units (2,3,4,8) are available from €800,00 to €3.200,00 … plus the wireless send /& receive kits for delivery €475 a pop. Ahhh, peanuts ….
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.
Thanks for reading!