Don’t Compromise On These AV System Components: Part 3
Back End Technology
Part one and two of this series discussed the importance of choosing the best displays, user interface, microphones, and speakers. The user interface and display allow you to visually interact with others. The microphone and speaker enable effective communication between one another. The hardware which processes the information from the front end components is what you don’t see. The back end components are vital to the operation of the conference or collaboration room
Different audio Digital Signal Processors (DSP’s) handle audio signals in different ways. These pieces of hardware take audio from microphones and often mix it with program audio from the video sources, to send to the far end of a conference call, or play the audio through the speakers in the room. It may seem that all audio processors that have the same number of inputs and outputs perform the same. This is not the case, because manufacturers often design their products to hit several price points by varying pre-amp quality and Acoustic Echo Cancellation (AEC) processing quality. Remember, not all inputs of your system are actually heard by users in your room. Many inputs into your system are only sent to participants on the “far-end” of a call (remote participants). If there is not a sufficient level of quality with pieces of hardware and software, the overall experience could be negatively impacted for all participants in the call or meeting.
When customers, especially potential ones, enter your space in person or remote, you want to ensure that you are providing them the best audio quality possible. It all starts at the input stage. All analog audio goes through a DSP’s pre-amplifier. Microphones need to be amplified up to line-level, whereas program audio sources often need to be amplified to a level consistent to all other audio sources. Audio DSP’s have varying pre-amp quality. This stage also usually involves some sort of analog-to-digital (A-to-D) conversion for processing and distribution of the audio signal through the rest of the system. Some DSPs on the market use pre-amps and A-to-D converters that are “good enough” for the average user. These may be acceptable in some rooms but not for most customer-related meetings.
In any space, microphones pick up all audio around them, no matter if it comes from a speaker, or the people talking. If a participant is on the far end is talking, the microphone can pick that audio signal from the speakers, and send it back to the person who said it, producing an echo. What the Acoustic Echo Cancellation processing (AEC) does in DSP’s is compare the audio captured from the microphones, and compares it to a “reference” signal within the processor. Every brand of audio processor has different processing to handle the echo. Some DSP’s AEC processing is better than others. Some manufacturers have completely updated their AEC processing algorithms depending on the software version of the product. One of the often-published specifications of a DSP’s AEC processing is the tail-length, the length of time the AEC processor can remove audio from the microphone’s signals. Large rooms and rooms with hard walls can have a long reverberation time, requiring a longer tail length to ensure all the audio signals bouncing around the room get canceled out.
AV over IP solution
AV over IP solutions are not new, but lately, this has been the current “buzz word”. AV over IP takes native AV signals and compress them into packets that can be sent across the network. Often times image quality is sacrificed to get the video signal compressed enough to fit on a 100 Mbps network connection. Now with 1 Gbps networks, and modern compression algorithms such as H.265, JPEG2000, or other “lossless” algorithms, the industry is able to send AV signals across networks that look acceptable for the majority of use cases. As before, how important are your use cases, especially if customers are involved.
Manufacturers of these devices must ensure their products are secure and safe to be placed on the network. There are numerous network security measures that can be taken. Most should support some sort of AES encryption and support HDCP encryption for copyrighted videos such as Blu-ray movies, cable, or satellite receivers. Most major AV manufactures have published security standards and practices that are available to their users.
While this is not a physical component, maintaining an existing AV system is critical to ensuring the users will get the lowest cost of ownership. Regular service visits should be made to keep the room performing as desired. All components should be tested individually and as part of the operational system. If the system is located on the network, it is a good practice to ensure that all pieces of equipment have the current firmware versions loaded to patch any potential security issues.
Although vendor certifications also aren’t a system component, they are important to give confidence that trained individuals are working on your system. Many manufacturers require that certified individuals are employed by integrators to even have access to their product lines. This safeguards that their products are being installed and configured by technicians who know all the aspects of the product. The last thing the manufacturer wants is an end-user to think there is something faulty with the product when it is in fact just configured poorly.
Work with an AV Professional that can create a system that will meet your needs for the space. They should work with you to figure out what your requirements are, where would be the best places for you to spend more money, or cut from others. Some things that you thought were going to be challenges may have simple fixes that they have encountered with other clients.
Many integration firms will often try to force specific models of hardware on their clients for a variety of reasons. Ask questions as to why they are using one piece of equipment over another, and ensure that the reasons are for your benefit.