Anna Mitchell recently caught up with Xavtel’s Romano Cunsolo to find out why good sound in a conference is essential and learn more about how Xavtel is helping businesses achieve this aim.
AM: Are there any important emerging technologies that will improve the capture and processing of speech in conference environments?
RC: First of all talking only about table-top microphones, manufacturers have started using multiple microphone capsules and mixing in analogue or digital.
When it comes to the conference system, from Xavtel’s point of view, the microphone must have a good quality and it must have a certain pattern that the person can speak into. The biggest problem that we face in conference is that people using it will speak at difference distances from the microphone.
It can be that people go very close because they are used to a microphone with a very low volume. Other people lean back and start speaking very low. So what do you do? You can never know who is there.
Xavtel created AGC (automatic gain control) software. This means you can get very close to the capsule the volume does not get really much louder, you will not be able to override the capsule or distort the sound. Of course if you go further away and microphone doesn't detect any sound it tries to raise up the gain but only until the point where there is no feedback. We have an auto mix minus calibration unit. This calibrates every single microphone to the highest gain before feedback in conjunction with our AEC.
It's very difficult to change people's behaviour. Of course, if someone works for a long time with one conference system they know the reaction and they know the feeling of it. They might adapt. But that’s not usually the case and you don’t want users to have to think about it.
Other developments are in areas like recording. With our system you just push the button on the main station then you start a recording. It's a USB flash. After the conversation, you just pull it out and it creates a .wav or MP3 file with the time stamp.
Within Senator UC we have three systems. It is a standard conference system with all functionality you would expect. Secondly, we have an AEC card integrated and that means there is no need for any external DSP, AEC or mic inputs. We have VOIP and SIP functionality inside that unit that means from your standard conference system you simply dial a number and go out and you dial to a different conference. The third system is on our main unit and it allows you to connect via USB. You start a web conference using a system like Skype for Business.
AM: Where have the biggest recent advances been made?
RC: I have worked with AEC systems for 15 years. One real benefit for us for all in the industry is that in former times the DSPs were not dedicated to only handle AEC. Today we have a chip inside our Senator Octo that is 100% dedicated to perform for AEC. It also has a very long tail length of 355ms.
AM: Could you outline what tail length is?
RC: Tail length is the time it gives you to converge to find the right distance between the loudspeaker, the microphone and the room. So the longer the distance, the bigger the room the more tail length you need.
A lot of AEC algorithms in the industry don't have enough tail length to be really working in a big room. It's just impossible.
AM: Are there any major breakthroughs in microphone development?
RC: The breakthrough for us is that we combined the three systems in one. Our aim was to ease the set up and use. Therefore we have our automatic mix-minus calibration, which automatically deals with the room acoustics because it calibrates the gain structure of the whole system in a mix-minus set up automatically. It's just a push of one button.
At the same time it measures the distance from every speaker to every microphone. So the pre-sets or the settings for the AEC are already in the machine. There is no set up used or needed for the AEC. AEC needs referencing from the far side and the referencing from that input needs to be in an exact value or in conjunction with the exact microphone you want to cancel out. Otherwise if the levels are incorrect it's a nightmare. It will not work. This is all automated. We want to make it easy for the end user and the integrator.
AM: What maintenance considerations should installers take into account when deploying microphones?
RC: You can have centralised and remote management. All our Senator systems will be controlled over an Ethernet network so you can have a remote computer somewhere. You can program multiple units at the same time. You can monitor multiple units at the same time.
Our audio networking capabilities are not only limited to Cat5, we also offer fibre optics. That means that distance is no longer a problem. With Cat you can only go 90 to 100m and then it's finished. You need a switch or a hardware device to go further. With our networking card and our junction boxes you can actually go 2km on multimode or you can go 20km on single mode. This way you can network several buildings.
AM: What is the biggest battle for integrators/consultants trying to sell the importance of good quality audio for conferencing (including video and audio conferencing)?
RC: If you ask users if they have always had a good experience with conferencing systems most people will say no. If you ask them why, there are usually two answers: they didn’t know how to operated it or it sounded awful.
It's so hard to understand somebody and if the sound is not good what do you do? Think about what the most important thing is in a video conference? Is it that the video signal must be good? It’s great if you can see someone 10,000 miles away but if the audio is gone what do you do? It’s surprising how many people have never thought about that. It's not only that the audio is there or not, it's the quality of the audio, the intelligibility. If it’s not good then you cannot communicate in a relaxed way. It's very annoying and after half an hour your concentration is gone. We believe good sound in a conference room is an absolute must.
Xavtel is featured in a wider article on microphone technology that you can read here.