1 Cisco Webex SX80 and Codec Pro Based Systems Using Extra Loudspeakers and Sound Reinforcement A guide to provide a better auditory experience D1536505D1536505 Cisco TelePresence Using Produced:Extra Loudspeakers March 2019 for CE9.7 and SoundAll contents Reinforcement © 2016–2019 Cisco Systems, Inc. All contents © 2016–2019 CiscoAll Systems, rights Inc. reserved All rights reserved. 2 Contents What’s in this guide Contents Introduction ......................................................................................3 Codec SX80: Use with Extra Loudspeakers (I) ...............................4 Codec SX80: Use with Extra Loudspeakers (II) ...............................5 Codec SX80: Expanding Scenario to Include Local Presenter (I) ...6 Codec SX80: Expanding Scenario to Include Local Presenter (II)...7 MX700/800: Use with Extra Loudspeakers .....................................8 MX700/800: Use with Extra Loudspeakers .....................................9 MX700/800: Expanding Scenario to Include Local Presenter .......10 MX700/800: Expanding Scenario to Include Local Presenter ....... 11 Codec Pro: Use with Extra Loudspeakers (I) .................................12 Codec Pro: Use with Extra Loudspeakers (II) ................................13 Codec Pro: Expanding to Include Local Presenter (I) ....................14 Codec Pro: Expanding to Include Local Presenter (II) ...................15 Audio Console — Customizing the Audio Connections ...................16 The Audio Console Panel ..............................................................17 Setting Up the Equalizer ................................................................18 D1536505 Cisco TelePresence Using Extra Loudspeakers and Sound Reinforcement All contents © 2016–2019 Cisco Systems, Inc. All rights reserved. 3 Introduction Get Inspired When using the Codec Pro or the SX80, In need of a little inspiration when it Main you may want to use more than one pair of loudspeakers comes to designing video meeting loudspeakers in the room to enhance the scenarios? overall auditory experience. Check out Project Workplace (https:// When using the Codec Pro or SX80 with local projectworkplace.cisco.com/#/) which sound reinforcement, extra loudspeakers are Extra may serve as inspiration when you strongly recommended to ensure that people in loudspeakers want to build your perfect meeting the room get the good auditory experience. scenarios, explore our collaboration To set up the system we recommend to use the products, and discover experiences. Audio ConsoleNEW. Typical scenarios when a codec is used with extra loudspeakers. Alternatively, you may use parts of the API of the codec. The use of Audio Console to set up a system for local reinforcement is discussed at the end Main loudspeakers of this document. We recommend delaying the sound from the extra set of loudspeakers to take advantage of the Haas effect. Extra loudspeakers The Haas effect (also known as the Precedence effect) causes humans to localize sound sources in the direction of the first arriving sound despite the presence of a single Typical scenarios when a local presenter (lecturer) uses a wearable microphone reflection from a different direction. A single and local reinforcement is used to enhance the auditory experience in the room. reflection arriving within 5–30 ms can be up to 10 dB louder than the direct sound without About Microphones and Echo Cancelling being perceived as a secondary auditory event. If no more than 8 microphones are required, we do recommend that you stick to To a listener located in sweet spot, the two the 8 independent built-in echo cancelers of the codec. These are high-quality extra loudspeakers will combine into a single cancelers closely integrated with the internal mixer, loudspeaker sound processing phantom source and thus cause no violation of and the general signal flow inside the codec. the single reflection requirement. The use of external echo cancelers will normally introduce additional delay with reduced lip-sync performance as a result. In addition, you will experience increased cost of installation and maintenance. D1536505 Cisco TelePresence Using Extra Loudspeakers Note We do not recommend using local reinforcement in combination with SpeakerTrack. and Sound Reinforcement All contents © 2016–2019 Cisco Systems, Inc. All rights reserved. 4 Codec SX80: Use with Extra Loudspeakers (I) Connecting to the Codec Main loudspeakers Extra loudspeakers The illustration at left shows the external connections needed. Note that, for clarity, the camera connections have been omitted. The illustration shows a configuration using passive loudspeakers and a power amplifier. Active loudspeakers (with built-in power amplifiers) may, of course, be used instead. You may use any number of local microphones. Shown here is the maximum number the codec supports, which is 8 microphones — see Local microphones also “About Microphones and Echo • Line outputs 1– 4 are standard Cancelling” on page 3. “speaker outputs” (line level) that go LAN through the volume control. Your presentation source may be • Line outputs 5 and 6 are “record connected using either HDMI or DVI. In outputs” that contain local the latter case, audio must be provided microphones as well as far end and program material. separately to the codec, as shown. • The example shown here reflects the codec’s standard behavior. This For clarity, the HDMI PC-input audio may easily be modified by means of alternative has been omitted in the the Audio Console (described later in this document). illustration of the internal signal paths shown on the following page. (For clarity, no camera connections are shown) Touch 10 Display(s) D1536505 Cisco TelePresence Using Extra Loudspeakers and Sound Reinforcement All contents © 2016–2019 Cisco Systems, Inc. Presentation All rights reserved. source 5 Codec SX80: Use with Extra Loudspeakers (II) • For the initial configuration when • A further 5–30 ms of delay setting this up, we recommend should be added to the the use of a sound source calculated delay difference to connected to the video system take advantage of the Haas as “local presentation outside effect — see page 3 for more on l1 l2 a call”. Make sure you use a this. signal with a representative The exact amount of delay is content and signal level, as well difficult to predict, try listening to l3 l4 as sufficient dynamic range. the entire system while adjusting Recorded speech should be a the delay. Use the sweet spot. part of this signal. Sweet spot Ideally, you should hear a rich The sweet spot is normally the position where things We recommend that level • sound without being very much should sound the best. We recommend that you apply setting on the audio output a delay setting to the extra loudspeakers to make things aware of the presence of the connectors is kept at its default sound better. This will require that you measure the extra loudspeakers, while at the value (-10) distances shown—see text for more. same time it should be clearly The extra loudspeakers’ level noticable when you switch off SX80 should then be set as suitable, the extra loudspeakers. Audio from Far End (including any Far End PC-input audio) using the loudspeakers’ own gain controls. • This delay adjustment may involve output level adjustment Master Volume Gain This will leave a range of –14 dB for the extra loudspeakers, but to +10 dB available for further not necessarily. adjustments, which will be PC-input audio & Far PC-input audio needed if compensation for Use output level in the codec End audio sent to main • loudspeakers many people present in the API to adjust the balance room calls for a different level. between the main and extra Audio to Far End loudspeaker sets. Define a sweet spot (normally • The entire setup should then PC-input audio the position where things should • be tested with people in the sound the best). room, alternatively with an • Measure the distance between amount of absorption material corresponding to such a Delay the sweet spot and all of the Adaptive PC-input situation. echo loudspeakers, as shown at right. audio and cancelers Far End This may call for further level Gain You should now introduce a audio sent • adjustments, as outlined above. to extra delay to the sound from each of loudspeakers the extra loudspeakers. • Be sure to make a video call to PC-input audio This delay will correspond to the test that the far end experience D1536505 distances – and – . has the quality required. Cisco TelePresence l1 l3 l2 l4 Using Extra Loudspeakers As a rule of thumb, use 3 ms and Sound Reinforcement delay per meter. All contents © 2016–2019 Cisco Systems, Inc. All rights reserved. 6 Codec SX80: Expanding Scenario to Include Local Presenter (I) Connecting to the Codec Main loudspeakers Extra loudspeakers The illustration at left shows the external connections needed when expanding the scenario to include a local presenter. The only difference from the original scenario is the introduction Wireless microphone of a wireless microphone and its base for local presenter station (shown in green). The use of a wireless microphone is not mandatory, wired microphones may also be used. In addition, you may also use any of Wireless the microphone inputs for the local microphone presenter. If you need more than one base station for this, use the number needed, just observe the danger of feedback if care Local microphones has not been taken (see the following • Line outputs 1– 4 are standard page for more on this). “speaker outputs”