Indian Oil Corporation Limited is an Indian government owned oil and gas company headquartered in New Delhi. It is the largest commercial oil company in the country, with a turnover of Rs. 506,428 crore and a net profit of Rs. 21,346 crore in 2017–18. It is ranked 1st in Fortune India 500 list for year 2016 and 117th in Fortune Global 500 list of world’s largest companies in the year 2019.
Their eastern regional office located in Dhakuria, Kolkata, the eighth floor of the said office is being renovated which was planned to be equipped with a advanced classroom style conference hall with dimensions Width-6.7mts x Length-19.2mts for internal training and departmental discussions.
- Minimal number of microphones for the attendees,so that all Managers/ Officers/ Management Trainees are able to talk freely without bending or moving their chairs.
- Seating arrangement was 3 person in each bench with 18 seating arrangement. Considering 1 microphone on the outer edge of each table as there were pop-up boxes for power connection, internet and audio and laptop spaces which could not be disturbed, the speaking distance will be around 3.5ft/4ft from the person sitting in the middle and 4ft/4.5ft feet from the persons sitting on the edges.
The classroom has an height of 3mtr in the front and 2.6mtr at the back, elevation of .4mtr which makes it immensely prone to feedback during audio conferencing locally as well as video conferencing with far end users.
Recommendation and design
As per the requirement of the client and keeping in mind the profile of the attendees we selected beyerdynamic RM31SP Vertical Array Microphone to be located in the middle of each seating arrangement table. Wireless Headworn Microphone beyerdynamic TG534 were recommended for the presenter, beyerdynamic TG550 has been recommended for extra sitting or emergency purpose for the said scenario.
We decided to go for QSC Core110f DSP for controlling to manage the entire A/V platform. QSC CXD 8.4Q Amplifier and QSC ADC-4T Speakers for audio reproduction and audio conferencing has been recommended.
For audio controls we have used a QSC TSC-7t touchscreen controller in which we have recommended on using a custom UCI for controls of the entire AV solution using the QSC SL-QUD-110-P license.
For 3 X 3 Video Wall LG 49VM5C turned out to be the perfect match owing to the space requirements. We recommended the Kramer’s VP-734 which is a 7 input presentation switcher with control options of RS-232 for switching facilities from different inputs, Kramer VM-4H2 is recommended for multiple distribution of the same information to other units on the same floor in future.
Polycom Group500 along with Multiparty license for 1+5 participants and Full HD license for 1080P calls has been recommended for multi-location training and high resolution output.
The standard distance speaking distance of RM31SP is around 2.5ft to 3ft, but we decided to do some major DSP enhancement controls for the said arrangement and but the speaking distance in this case was around 3.5ft/4ft from the person sitting in the middle and 4ft/4.5ft feet from the persons sitting on the edges. Q-Sys Designer Software helped us in designing the system and loading it into the QSC Core110f , we have increased the gain of the microphones in the DSP, also we have reduced the threshold for opening the gates of the microphone using the automatic gating mixer, that did the magic and we could easily get response from a distance of upto 4ft, we also tried with different voice nodes to determine the automatic gating mixer working perfectly.
We have used the QSC CXD 8.4Q amplifier as the number of microphones we are using is 21 and we also needed an audio input from the video conferencing , the QSC Core 110f allows upto 8 input and 8 flex channel which makes it 16 inputs and thus the QSC CXD 8.4Q allows us to add 4 more mic /line input to the system with phantom power facility and is also a network amplifier which allows us to program and manage the inputs which are going through the QSC CXD 8.4Q amplifier too.
Video Conferencing solution made it even harder for us as this needed Acoustic Echo Cancellation (AEC) channels for all the channels or else the output on the far end would be compromised, the Core 110f allows 16 channel AEC in default in 200 ms tail length, we have used 21 AEC channel with 100 ms tail length to make the performance optimal. We have used 100ms tail length here as the room is very compact and acoustically well treated.
The USB channel of the QSC Core 110f has been used as the local laptop’s audio input and treated as a sound card, the USB channel will also help in recording facilities in the laptop for any Video Conferencing or Audio Presentation / Conferencing. Audio Player option has been provided with preloaded playback songs for BGM purpose. The entire AV control is given in the QSC TSC-7t and as this is totally customisable in the QSC Designer Software, we have designed the same as per IOCL specifications ,colour theme and logo.
As already discussed the classroom has an height of 3mtr in the front and 2.6mtr at the back, elevation of .4mtr which makes it immensely prone to feedback during audio conferencing locally as well as video conferencing with far end users. With the help of the QSC Designer Software we have used the mix-minus technique to adjust the gain of the nearest speakers from the microphone to avoid feedback, this became a challenge as the last seating arrangement was only 2.6mtr from the ground and almost 1.6mtr from the microphone, therefore we have connected 2 alternate speakers in a single channel so that the sound gets equally distributed in the entire conference room.
We have taken the audio out from the QSC Core110f and included that into the Polycom Group 500 to include the microphone input in the Video Conference.
The 3×3 LG 49VM5C video wall connection has been established using daisy chain , The Kramer VM-734 has been used for using of multiple inputs and switching between them, we have used one of the inputs for Video Conferencing. Kramer VM-4H2 have 4 HDMI output, 1 is allocated for the video wall, 1 is allocated to the Video Conferencing to display local laptop content to far end users, 2 more outputs are kept free as of now for multiple distribution in future.
The entire system has been designed and implemented keeping on mind the client’s issues and the structural issues.The end result is perfect as per client’s preference and our satisfaction.
We evaluated the microphone settings by means of multiple seating and using different voice levels to check the audibility of the microphones and their reproduction without moving from the chairs or bending towards the microphone.
During the trial video conferencing by sitting in different locations, no feedback was experienced at the local end as well as at the far end, and the entire meeting went uninterrupted.
To identify any issues pertaining to audio reproduction from the last seating arrangements, we have done mock seating and tried out multiple voice levels to conclude that the mix-minus is working perfectly. The result came out to be as desired and no flaw was detected.
After the site handover to client, client has successfully conducted several trainings and internal meetings with multiple Video Conferencing locations which turned out to be successful with minimum external handling.
Thus, this brings us to yet another successful installation for our revered client Indian Oil Corporation.