This is the first of a series of articles called “More Than You Wanted to Know About Sound Systems.”
Let’s Discuss Volume
To discuss sound we need units of measurement. The decibel is a logarithmic ratio of two levels, used to make manageable numbers from large ratios. Like 60 dB is one million to one. We will use two comparisons for sound. SPL sound pressure level and dBm electrical signal level. SPL is sound measurement. While dBm is a broadcast standard electrical level for audio equipment.
The question is “How loud does your audience want you to be?” Playing my acoustic and singing (badly) measures 85 dB SPL @ 1 meter (39”).
Distance Is Important
Sound level decreases by -6 dB SPL for every doubling of the distance. So at 8 meters (26ft) we are down 18 dB SPL. So now we are at 67 dB SPL, a quiet room.
You Might Need a Sound System
You need a sound system to connect with more than a few people. To make the best use and have the most control over your sound, everything should go through PA. Like when the cops tell you to turn it down. More to have same mix everywhere. An amp on floor doesn’t have same coverage as speaker on a stand. Sometimes more important than volume is coverage. Loud on the dance floor, quieter on sides. Or 85 dB for everyone.
Buy What You Can Afford
Best equipment is stuff you can afford, (best when it pays for itself) and you can move and set up easily and dependably.
Next we talk about your ears, the only measuring device that counts. Keep your levels up and don’t fear the reverb.