Small Venue, Big Challenges: A Smaart Case Study
Smaart in Small venues. Clubs are often harder to tune than arenas. Why? Reflections. In a 200-capacity room, the walls are close, the ceiling is low, and the “room sound” dominates the “PA sound.”
The Problem
Imagine this: A certain “someone” mentions a sense of “muddiness” in the audio in the local live music pub, despite his third-octave-banded RTA on the cellphone looked somewhat neutral.
So you agree to pay the place a visit. You bring you measurement kit and right. at firing up Smaart you immediately notice a second spike in the Live IR (Impulse Response). For the public: That is the reading on top of the three windows in a Transfer function measurement in Smaart. It is the first thing a good Smaart Operator looks at, not only to time-align his TF measurement, but also to see such things – academically called analysing the reflection structure of the room. Well, there is a massive reflection – apparently from a glass surface (normal people say window) near the main right PA, arriving only 2 ms after the direct sound at FOH where you just placed you MELLab.
some Smaart Z2H Seminar information can be of use here …
When two identical signals arrive with a 2 ms arrival time difference, they create what is known as a comb filter, because the measurement looks literally like a comb. This delay causes frequencies to interfere constructively or destructively depending on their wavelength relative to the 2 ms offset. The example calculation is based on the signals having the same amplitude.
Comb Filter Peaks and Nulls (2 ms delay, equal amplitude)
Nulls (destructive interference) 250 Hz, 750 Hz, 1.25 kHz, 1.75 kHz, 2.25 kHz, 2.75 kHz, 3.25 kHz, 3.75 kHz, 4.25 kHz, 4.75 kHz, 5.25 kHz, 5.75 kHz, 6.25 kHz, 6.75 kHz, 7.25 kHz, 7.75 kHz, 8.25 kHz, 8.75 kHz, 9.25 kHz, 9.75 kHz and so on …
Peaks (constructive interference) 500 Hz, 1 kHz, 1.5 kHz, 2 kHz, 2.5 kHz, 3 kHz, 3.5 kHz, 4 kHz, 4.5 kHz, 5 kHz, 5.5 kHz, 6 kHz, 6.5 kHz, 7 kHz, 7.5 kHz, 8 kHz, 8.5 kHz, 9 kHz, 9.5 kHz, 10 kHz and so on …
The Solution – “Absorption”
A Smaart operator knows that EQing can’t fix such a problem. You were lucky and the owner of the place was understanding as well as cooperative and installed a heavy curtain he could pull in front of the window during concerts. No reflection – no comb filter.
Takeaway:
Also, in small rooms you can use a Dual FFT Measurement tool like Smaart to identify what can be fixed with EQ and what must be fixed by treating the room. Even though this is sort of obvious to an avid sound engineer, it can be a tricky discussion with the club owner.
Mostly it starts with audience complaints or bad reviews about the sound quality, so the sound guy is already on the defense. Not a good start for a constructive and positive discussion, so when you do your venue evaluation (big word for just having a look at the 200-cap club), you were guesstimating that this will be a bit tricky. The conversation possibly involving raised eyebrows and crossed arms.
So, armed with laptop, your trusted Audient EVO sound-card, your MELLab TX-3 wireless kit – all neatly hidden in your laptop sling – you arrive in style by public transport and are set up in minutes to start measuring.
That issue described before shows up instantly. Since you have a wireless mic, it does not take much effort to sample some more positions in the room, ideally without anyone noticing or panicking. Using your wireless MELLab kit you avoid destroying the carefully set-up table decorations by pulling your microphone cable around.
So in the process you are maybe already identifying the mid–high top misalignment colleagues mentioned, etc. After 15 minutes you know more about that club’s PA than the “locals” … okay, that might sound arrogant, but hey, knowledge has a habit of doing that.
Tip: try to be smarter than me and do not run the club owner and open the conversation with “Dude, there are a lot of problems with your PA, the subs – oh man …”. Be nice and kind and – what was that word again: diplomatic, yes.
Anyway, draw the curtains in front of that big-ass reflection and Bob’s your uncle … or is it Bob’s your bruncle? At this point, no one dares to correct you, and peace is restored.
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!