These are some of the technologies that have shaped Live Sound. Some of them are obvious changes that everyone has seen, but some are latent.
Rare Earth Magnets
Alloys made with materials like neodymium, beryllium, and samarium-cobalt have revolutionized transducers. Neodymium magnets in microphones like the Sennheiser e935 allow higher output and extended high-frequency response. This magnet allows rugged dynamic microphones to perform similarly to their studio condenser cousins on the road. Those same rare earth magnets have enabled driver technologies that output more level with less weight. This is another element that manufacturers have used to trim more precious ounces off the weight of their speakers.
Ever seen a long series of speakers hanging from the trussing? These have replaced the traditional huge stack of speakers on the stage. These hanging speakers are often pulled back in a J-shaped curve, called line array.
Turn a speaker up to its maximum output level, the only real option to make it louder is to double the number of speakers you are using. With traditional point-source speakers, this can get messy very quickly, as their coverage patterns will start to interact with one another in both constructive and destructive ways. This makes the sound experience vary greatly as you move around to different listening positions in a venue.
To cheat physics, for sound engineers, the line array is a key opportunity!
Powered Speakers with Lightweight Amps
Linear amplifiers (like Class A, B, and AB) suffer from inefficiencies in power transfer that require large heat sinks, and this means extra weight. A great-sounding speaker may seem considerably less attractive if it weighs over 70 pounds — requiring regular visits to a chiropractor.
Class D amps have practical efficiencies of over 90%. Speakers like the JBL EON series and the Electro-Voice ZLX series can output more than 120dB of SPL and weigh less than 40 pounds. Smaller speakers and less weight mean less strain on your back.
Digital consoles have caused such a paradigm shift in live sound that we really have to break down these changes into sections. One of the first is the transport of signals from the stage to front of house (FOH).
Protocols like Dante, AVB, and AES50 can travel over industry-standard twisted pair cables. These platforms not only allow use of cheap and light cabling for transport of massive numbers of channels (up to 512 x 512), but they also greatly increase flexibility. Making a duplicate split of your inputs for a monitor desk or a broadcast feed is now done in software rather than by buying tons more hardware.
High-end consoles often have virtual soundcheck built in, but its value has seen it added to more mainstream consoles like the PreSonus StudioLive Series III, as an option to Behringer/Midas consoles via the Klark Teknik DN32-Live, or with any analog console via the JoeCo BlackBox. Of course all of these options also let you record the show in multitrack so you can prep a live recording for fans.
The mixer position at a show is often not at the best place to hear, but it is where you are listening to set your levels, EQ, and ring out the monitoring system — certainly not ideal.
Being able to walk the hall with an iPad and make tweaks to things while you are standing where you need to hear correctly is a significant tool that can make an engineer’s life much easier. This approach has so revolutionised mixing that now there are frequently times when a performer doesn’t even know where the engineer is — which might be just the way they like it.