Hurrairah bin Sohail meets with DK Vascon and discovers the thought and consideration that went into designing and deploying the audio system at an art centre in Korea.
The Cheongyang Art Centre is a venue outside of Seoul, Korea where students, musicians and a wide range of artists can gather together and perform. When the end user decided to upgrade the audio capabilities of the venue so that the auditorium could better perform its function, DH Sound Professional Engineering Group was brought on-board in the capacity of system integrator to handle the project.
Kim Nam Jin, CEO of DH Sound, says regarding his involvement: “We were responsible for all aspects of the project from the designing, to the deployment and then eventually tuning and commissioning the audio system. I personally have decades of experience working in the AV industry and so designing an audio system for this auditorium was not a problem. However, designing an audio system that met the requirements of the end user and also stayed within the budget they had allotted was the real challenge.”
The Cheongyang Art Centre was previously fitted with Electro-Voice Xi1152 speakers which were supported by the Electro-Voice CPS series and Electro-Voice DX38 with a Soundcraft mixer.
Jin talks about the factors that made the end user decide to upgrade: “The Electro-Voice system was old and was beginning to show its age. Plus, the end user felt that it was no longer providing the coverage that the auditorium needed. The Cheongyang Art Centre needs audio for both music and speech which is difficult for any speaker to manage.”
The integrator decided to select Renkus- Heinz point source speakers in a 7x7 left-right configuration to provide audio for the auditorium along with QSC amplifiers and Symetrix DSPs. The decision to choose point source speakers instead of line-arrays was one that was not taken without due consideration.
Jin says: “We thought long and hard about what type of speaker would be the best for the auditorium. A typical line array speaker unit has a vertical dispersion of 7 degrees to 10 degrees. Due to the shape of the auditorium we needed a total of 110 degree coverage. This would mean that we would require 11 line array speaker units and there just wasn’t enough space or the budget to accommodate this kind of system.”
He continues: “On the other hand, the Renkus-Heinz point source speakers have a dispersion of 15 degrees. Which meant that with just seven speakers per side we were able to cover the entire space of the auditorium. Line array speakers are very good when you want the audio to be focussed on one point and the surface is flat. But in a sloping auditorium or theatre they do not perform as well.”
The model of the point source speakers was also decided after careful deliberation. Jin says: “The Renkus-Heinz speakers were chosen due to their performance and oddly enough due to the size of the enclosures. JBL and Electro-Voice have similar speaker models but with smaller enclosures. I found that the larger enclosures allowed the sound to propagate better in the auditorium and this was a big strength and plus point in favour of the Renkus-Heinz speakers.”
Once the audio system was deployed, the integrator made sure that it was tuned and tested. Jin says that they deployed 10 microphones across the hall to make sure that the right SPL levels were achieved.
He goes into further details: “A particular problem with audio in auditoriums is what I call ‘cave system’ or ‘cave sound’. Audio at the front is good but the audio at the back of the space can tend to be a little dry. We solved this problem by adjusting the centre and front speakers which is quite easily done through a program.”
Audio is transmitted via analogue cabling. Jin says: “Analogue cable quality today is really good. There is very little cable loss or noise. Additionally the distance for audio signals to travel is less than 100m. If it was more than 100m I would have considered digital signal transmission via Dante or AVB. But since it was not needed I decided to go with analogue cabling. Personally, I prefer analogue cabling as I feel that digital sound tends to be a bit dry.”