10 OBSOLETE
Audio Terms
By Anthony P . Kuzub
The audio and video industry is currently experiencing an IP renaissance . With the deployment of AES67 networked audio solutions , certain terms from our pro audio vocabulary are in need of revisiting . Though these terms are commonly used in analog and digital transmission , with the emergence of AES67 and SMPTE ST2110-30 , the mechanisms of moving audio have been completely re-invented . The terms must follow .
The following 10 obsolete audio terms are discussed and broken down , and some potential replacement terms are suggested for their modern IP equivalents .
SPLIT
A single microphone on stage in a performance has to feed the talent , the audience , the recorders , and the broadcaster . For decades , we ’ ve been relying on iron core isolation transformers with miles of fine copper to perform this splitting of delicate signals . Lately , these same electrical primitives are in use between the front end of multiple digital mixing consoles . Different sample rates , different clocks , and proprietary vendor ecosystems force this . The redundancy of analog to digital conversion with active and passive splits is no longer needed on a converged network . With AES67 being multicasted onto the network , an engineer subscribes to the sources needed to perform the task of signal splitting . The network switch is the most powerful audio splitter ever made and costs less than the road case for the splitter for which one could pay thousands . It ’ s time to stop splitting and start multicasting .
PATCH
We have been weaving , making , and breaking audio signal patches since we ’ ve had a need for them . As the quality of microphones went down , the quantity of them went up . As we made studios and facilities larger , the need for flexibility went up . Multiple sources from different rooms needed to be strung through buildings and hard wired for a limited and specific purpose .
As AES67 is using a Layer 3 networking protocol , the need for single application rigid physical infrastructure disappears . As all of these signals converge in a network , we ’ re not patching them from source to destination ; the destination is joining an Internet Group Management Protocol ( IGMP ) stream . As the sources populate the network , the receivers can have access to that signal .
We ’ re not using patch cables anymore to connect sources and destinations . We ’ re trading a Session Description Protocol ( SDP ) and we ’ re using software to request a stream delivered through IGMP . We ’ re not patching ; we ’ re joining IGMP streams !
Figure 2 : Matrix Routing with Aneman : A Network Manager by Merging Technologies
Figure 1 : Unicast - Broadcast - Multicast network traffic Unicast
Broadcast
Multicast
38 PROFESSIONAL SOUND