DALLAS — Among the new products getting noticed at last week’s 2019 Radio Show is an appliance for Wheatstone‘s WheatNet-IP audio network that addresses “the unique challenges of multiple program streams.”
Attendees got the chance to see the StreamBlade — a 1 RU BLADE unit for streaming applications that features key Wheatstone AoIP, audio processing and codec bandwidth optimization technology.
Among the abilities of StreamBlade are selectable Opus, AAC and MP3 encoders targeting high to low bit rates for reaching a broad range of end user devices and players; the acceptance of eight input steams of native WheatNet-IP audio directly from a soundcard or AoIP driver as well as RTP sources, each capable of four outputs for a total of 32 total output streams; AGC, peak limiter and other audio processing designed to optimize the performance of encoded audio content; cloud-ready and compatible with standard CDN and streaming platforms, including Icecast, Wowza and RTP; metadata support for identifying song title and artist readouts dynamically from all the major automation systems; and 8×4 channels of local I/O connectivity for other than WheatNet-IP audio network applications.
“Putting all processing and bandwidth optimization functions in one box that talks native IP audio just makes sense for studios today that are managing five, six or more streams,” said Rick Bidlack, Wheatstone systems and lead StreamBlade design engineer.
Unique to StreamBlade is its five-band AGC with RMS density driven time constants for establishing tonal balance and level consistency between incoming music sources. Unlike the conventional approach of applying multiband gain control followed by fast compression to build uniform loudness and density from one music source to the next, this AGC is designed specifically for streaming applications and eliminates aggressive RMS attack times that can interfere with codec performance.
“Fast time constants (compression) can add intermod sidebands around a sustained note or bass note, which the codec has to spend bits on instead of the signals that are actually part of the program,” said Wheatstone audio processing line Senior Product Development Engineer Jeff Keith. “That can be bad for any stream, but it’s especially bad for low bit-rate streams that don’t have a lot of data bits to begin with.”
Also unique to StreamBlade is a two-band final limiter section made for streaming that removes hard limiting or clipping from the processing chain. “Clipping creates harmonics that the encoder wants to throw bits at, and much of that isn’t particularly pleasant to the ear,” Keith added.
Wheatstone makes a line of AM, FM and microphone/voice audio processors in addition to WheatNet-IP, a complete AoIP ecosystem of consoles, talent stations, I/O units, accessories and virtual tools used in studios around the globe.
StreamBlade can be configured and managed from a laptop and web browser using WheatNet-IP NAVIGATOR software. It has two Ethernet ports, one for direct connectivity into the WheatNet-IP audio network on one end and another for connectivity into a WAN for streaming to a CDN or other service provider.