RedNet At The Heart Of An Expanding Dante System

New England Conservatory (NEC) is located in the centre of Boston’s education cluster. With Northeastern across the street and Berklee a short walk away, a scholarly atmosphere mixes with the sounds of countless recitals flowing from open windows surrounding its campus. At the centre is Jordan Hall, NEC’s century-old performance space, which is listed on the National Register of Historic Places and considered to be one of the best-sounding concert halls in the country. Other venues around the school cater for everything from chamber recitals to contemporary performances, and on an average day there is a swarm of activity from students, faculty, alumni and musical visitors.

NEC’s stellar reputation is reinforced by the calibre of its past students, including John Medeski, Regina Carter, Vic Firth, Nat King Cole, Coretta Scott King and Bernie Worrell. NEC has offered music recording facilities for 50 years, since 1969. Today, the AV Services department, headed by Lisa Nigris, continues to provide recording, archival and production facilities to the faculty and students, and is growing as new technological advances open doors to new capabilities.

Lisa’s team comprises four professional recording engineers, whose day-to-day tasks range from recording NEC and rental concerts, supervising 23 student engineers on student recital recordings, mixing operatic performances and providing FOH and live recording production services for the many ticketed concerts that take place after school hours. Their ability to do this rests on a campus-wide Dante-based audio-over-IP system, which lets the team members control, monitor, record and archive audio from any performance space using any networked computer on campus.

Lisa notes, “NEC’s faculty and students are endlessly creative. It’s our job to support their vision and capture the performances without them even being aware of the sometimes herculean effort going into that support.”

The First Install

It was in Jordan Hall that the path to an audio-over-IP system began. “We were starting to hear noise and random interference in the analogue lines in Jordan Hall,” recalls Jeremy Sarna, Senior Engineer at NEC who has been working at NEC since 2000. Lisa adds, “after cleaning every patch point and re-soldering every connector, it became clear that the issue was the cable. Although high quality installation cable was used during the 1995 restoration, it appeared that the copper cabling was degrading and negatively impacting our recordings”. The AV Services team needed a solution. “It was the summer of 2013, around that time that Dante was starting to take off. Our first RedNet installation was January of 2014.”

The team’s immediate goal was to build a system that would circumvent the analogue cabling issues, but they also had their eyes on the future: plans were afoot to expand into a new building across the street, set to open in 2017. Sarna recalls, “the idea was to replace the existing analogue infrastructure with the thought that, if it works well, we can expand — so Jordan Hall was definitely a test case. In making the decision, we wanted to make sure that it was something that we could implement everywhere. We were looking at Dante and AVB at the same time, and the options for Dante seemed more appealing.”

At the time of the system upgrade, there were not a lot of Dante options available, so Focusrite units were among the first tested. Lisa Nigris recalls, “I was thrilled to discover that, not only was I impressed with the sound of the RedNet gear, we also knew that it was going to do what we needed it to do. The first Dante units that went into NEC were Focusrite RedNet 1 (8-channel A-D/D-A converters), RedNet 3 (32 channel digital I/O), RedNet 4 (8-channel microphone preamps) and RedNet PCIe cards, all from the first generation of the RedNet range. When this first installation was completed, we were all very impressed with the results.”

Once the first phase of the system was installed, the AV Services team embarked on adapting their operation with the new, IP-based infrastructure. Jeremy Sarna recalls, “It was probably the biggest change in workflow since I started here, which at that point was 13 or 14 years. So it was huge. There was definitely a lot to get used to, because it was very new for me at the time, but once I caught on to what could be done with the system, I was like ‘oh alright, this is pretty cool!’ It was a huge change because you had to go from thinking in an analogue way to using Dante Controller with its giant routing matrix. But once I got over that hill of getting used to how the routing and the interface was setup, I understood it pretty well.”

The Second Wave

Several years since the introduction of the Dante system at NEC, the team have expanded the size and capabilities of the network in multiple phases. Following the Jordan Hall test case, RedNet units were installed in the other performance spaces that occupy the wider Jordan Hall building, such as Brown Hall and the Keller Room. At the same time, the team upgraded to digital FOH consoles with Dante capabilities, so that the same input and output interface equipment could be shared for sound reinforcement and recording purposes (rather than using analogue splits and separate I/O systems for recording and FOH respectively). This second phase of the audio-over-IP system provided tangible benefits in efficiency and adaptability.

“As soon as it was confirmed that the new building was a go, I implemented a goal of the summer of 2017 for us to have all of the halls in the Jordan Hall and St. Botolph buildings running on the Dante network. This way, when the SLPC (Student Life and Performance Center) was completed, it would simply be a matter of putting them all on the same network. The idea of having eight concert halls — three fully equipped and five basically equipped control rooms — in three different buildings, all being interconnected, was very exciting!” says Lisa.

“When it came to designing the system for the new building,” says Sarna, “we first considered what was going to be the function of each room. That dictated how we equipped each space. For example, the Eben Jordan Ensemble Room is a performance space but also a recording studio, which obviously needed lots of inputs and outputs and the ability to work with high channel counts.” Lisa continues, “Burnes Hall, across the corridor, has fewer analogue lines but plenty of data jacks so we can accommodate all of the needs by bringing our mobile racks with all of the necessary gear, without installing extra cabling.” As a result, Burnes Hall and Eben Jordan share a single RedNet 4, which powers their permanently installed hanging mics (which are in every performance space on campus) and makes them available on the Dante network.

Data Network Design

When designing the data network in the new building, the AV Services team requested a dedicated audio network for Dante traffic however, that was not feasible. Instead, AV Services have their own subnet, which is essentially a segment of the campus-wide network ring-fenced for audio traffic. “There were lots of conversations between our team and the IT department,” says Jeremy, “to make sure that what we were planning was going to be possible on the network infrastructure that they were planning.”

This ability to scale the system up on the existing campus-wide infrastructure has enabled AV Services to hire and train student engineers to record the many recitals and some department events. Hannah Antolin and fellow engineer Alex Lisowski work closely with student workers, who are given limited access to channels and preamp controls depending on the space they are working in (and, crucially, nowhere else, to avoid accidental audio re-routes). “We now have 23 student workers,” says Hannah, “which is twice the amount compared to last year.” Jeremy adds, “Dante Controller is set up in a way that requires very little fussing around with it, so students can simply sit down at the computer and open a template for whatever they happen to be working on, and it just works. When they sit down at the computer and open the template for the room they’re recording in, they’re not necessarily aware of the things that are going on in the background to make it as easy as it is.”

The ease of use aspect to the system not only simplifies the recording process for typically non-technically-experienced students, it allows members of AV Services to diagnose problems and troubleshoot from a distance. Hannah Antolin elaborates, “we could be anywhere on campus and be able to grab a laptop and pull up Dante Controller and RedNet Control, and be able to see if a student was having problems, remotely, so we can help them out with it. This comes in handy for us, so that we can keep doing what we’re doing and make sure our students are also doing well. The ease of all of this stuff for them really helps things go smoothly all of the time.”

On Quality

NEC employs several different products from the RedNet range of Dante audio interfaces. On preamp duties, RedNet 4 and RedNet MP8R units provide clean gain and remote control to the various types of hanging mics in all the performance spaces. It goes without saying that the audio quality needs to be of the highest standard. Antolin acknowledges that having exceptional-sounding — but forgiving — preamps is important in the educational environment. “When our students are doing the audio engineering, occasionally they might over- or under-estimate the levels they should set for the hanging mics, so it’s definitely important for us to have gear that responds well if it accidentally clips or it’s way too soft and we have to gain it up later. Having gear that will compensate for the small margins of error when we have our students working is important for our workflow.”

Other RedNet equipment in the various facilities include RedNet 1 and RedNet 2 A-D/D-A converters, which interface between non-networked audio equipment such as their 500-series Grace Design and Great River mic preamps and Tube-Tech outboard compressors. RedNet AM2s also play a big role in the NEC setup: the two-channel desktop modules allow students and staff to monitor audio from anywhere with a network access point. Not only is this useful for monitoring recording sessions, but also for piping custom headphone mixes to visiting conductors and suchlike.

Next Steps: Video

As of 2019, the team are considering the pending expansion into video that Audinate promises with Dante AV: functionality that would be the missing puzzle piece to video capabilities that already take advantage of the audio-over-IP network. “Things are getting easier in terms of how much infrastructure you need to support video,” remarks Antolin. “All of our video is going over IP into our recordings, it’s just not using Dante yet.” The team creates HD video archives with embedded 24-bit/48kHz audio using software that marries the video from permanently installed cameras with audio from RedNet 4 or MP8R mic preamps in each room (via Dante Virtual Soundcard). “I think that as a team, we’re all pretty excited about the possibilities for audio and video and being able to send everything through the same protocol.”

In summary, the team are very proud custodians of the audio system they preside over. When asked if they could have imagined working on such a system five years ago, Alex comments “definitely not.” Lisa mentions “no, this system has allowed the department to work at a much more efficient level. I could not have imagined it.” With their ever-broadening horizons, the NEC Dante system promises to keep expanding for years to come.


Words & Pictures: Chris Mayes-Wright