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[Liam Flaherty]

I'm relatively new to measurement of systems but have been trying to do a lot of research recently and hopefully will incorporate it into my setup soon. My question is do you think measurement in smaller club venues (max 300 cap.) as a visiting engineer for system tuning is a worthwhile process or is it more suited to larger venues?

Appreciate any feedback as I'm still new to a lot of this! Cheers!

[Mark McFarlane]

If you have the time to measure, it can be helpful to understand the system and room interactions.  The low frequencies can be particularly problematic in smaller spaces, as can the position of the speakers,...

Measure if you can.

[Jay Barracato]

I use my measurement system for every gig I have room to set up a laptop. When visiting a venue, the measurement is more to check their tuning rather than to tune it myself. This is a dual channel measurement and you may not actually have a chance to make this type of noise.

I find having the spectrograph (one channel) patched to a cue bus to be extremely valuable during sound check and the show itself.

Sent from my DROID RAZR HD using Tapatalk

[Nicolas Poisson]

I work in a very small venue (50 pers!). I made tons of measurements. It definitely helped me. I think the system does sound better now than if I had never performed measurements.

However in small venues the benefit of dual FFT compared to single channel RTA is reduced. My understanding is that one benefit of the dual FFT is the ability to discard reflections. Basically, you can get a good approximation of the speaker system response, without room interaction, while keeping the microphone reasonably far from the system.
But in smaller venues, walls are so close that reflections will arrive right after the initial signal. There is so few time that separation between direct field and reflection is possible only for the highest frequencies. If you try to get a flat line on the dual FFT you will get the same drawback as the RTA: emphasized highs.

The measurement system remains useful because defaults of the system will still appear. But unlike in big venues, it will be harder to identify what is related to the system and what is related to the inherent limits of the measurement process itself.

Also, in smaller venues, you often have very limited choice for speaker placement, and it is very hard to get an even sound across the whole room. The response I measure at the mixing position in my venue is not flat. It is a compromise of the measurements I made on several locations in the room, and final adjustments by my ears. If you were to come in my venue and ask for a flat response on your display at the mix position, you would get:
- bad response at the mixing position (too much highs)
- even worse response at other locations in the room.

My feeling is that the measurement system is less useful in smaller venues than in big ones, and it is even less useful for a visiting engineer. But it may help if the system was not EQ'ed at all, just plugged.

[Merlijn van Veen]

In acoustics every room is in fact “two” rooms. One non-statistical room, that acts like a beer bottle and resonates, the modal part of the spectrum. One statistical room, that acts like a pool table filled with reflections, the specular part of the spectrum.

What constitutes a small venue? Textbooks say a room with a reverberation time of 1,6 seconds or less. If you rewrite the formulas of Bolt, Beranek & Newman and/or Schroeder you’ll find that crossing point for vocal content (80 Hz and up) is around 1.000 cubic meters. For instrumental content (30 Hz and up) around 6.500 cubic meters.

Smaller volumes or longer reverberation times will put part of the spectrum in the above examples in the modal area or “small” room.

The modal area requires a different approach than the specular area. In the modal area the frequency response can change dramatically from one position the next. You’ll need many responses at different positions to get a sense of the global LF envelope.

The specular area is very suitable for the traditional approach of on- and off-axis measurements.

IMHO measurements in small venues are very meaningful, taking the above in account. The physical size of the room has little to do with it.

I strongly feel that measuring, in general, is about confirming expectations. Not to map the response of the system.

The challenge is, what to expect…

[Chris Tsanjoures]

In acoustics every room is in fact “two” rooms. One non-statistical room, that acts like a beer bottle and resonates, the modal part of the spectrum. One statistical room, that acts like a pool table filled with reflections, the specular part of the spectrum.

What constitutes a small venue? Textbooks say a room with a reverberation time of 1,6 seconds or less. If you rewrite the formulas of Bolt, Beranek & Newman and/or Schroeder you’ll find that crossing point for vocal content (80 Hz and up) is around 1.000 cubic meters. For instrumental content (30 Hz and up) around 6.500 cubic meters.

Smaller volumes or longer reverberation times will put part of the spectrum in the above examples in the modal area or “small” room.

The modal area requires a different approach than the specular area. In the modal area the frequency response can change dramatically from one position the next. You’ll need many responses at different positions to get a sense of the global LF envelope.

The specular area is very suitable for the traditional approach of on- and off-axis measurements.

IMHO measurements in small venues are very meaningful, taking the above in account. The physical size of the room has little to do with it.

I strongly feel that measuring, in general, is about confirming expectations. Not to map the response of the system.

The challenge is, what to expect…

lots of cool info here! I think the biggest take away is that you have the ability to verify what you may already suspect. Just like driving a high performance automobile - when you understand what you have to work with, you can make better working decisions.

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