Trinity: A New Slant on Line Array Designs by FOH Online

Posted by Casey Hughes

June 2015 Issue, FOH Online

Developments in loudspeaker technology don’t seem to come along very often. Yet every day we witness new products, new materials and new approaches advancing the art and science of loudspeaker design. A good example of that kind of forward-thinking comes in the form of the Trinity system from Calgary, Canada-based PK Sound. (The system is pictured here in use at the Safe in Sound festival at Club Cinema in Pompano Beach, FL).

The Trinity was first shown at last year’s InfoComm. Technically that was a soft launch for this new technology, which includes two patents (one pending). The company’s intention at that time was to gather feedback from both clients (and competitors) and secure a select few key beta testers for the product.

After years of laborious R&D work, prototyping and highly successful system field trials under real-world touring conditions, Trinity — the world’s first mechanized, automated line array — is ready for its official debut. With that in mind, we spoke to company CEO/president Jeremy Bridge about the Trinity project, what it entails and where PK Sound is headed from here.

FOH: So what is it that makes Trinity different than traditional designs?

Jeremy Bridge: We have chosen to use electrical actuators to control the inter-cabinet angles as well as the horizontal dispersion, whether locally or remotely.

The actuators control the inter-cabinet angles, so instead of making these changes with manual rigging, where you would move a pin to a different pin-slot to adjust the different angles between cabinets, the electrical actuators are linked to the main rigging mechanism. You can adjust each cabinet from zero to six degrees in 0.1 degree increments.

The actuators can be tweaked and adjusted via PK Sound’s proprietary Kontrol™ program, which offers network-based remote access to the actuators and all the DSP features.

We also wanted to make the system as flexible as possible. Even if you are rushed and don’t have time to set up or use network control, you can just set cabinet angles via local control. Or in something like a racetrack situation where you have a circular track with stacks of four boxes on carts angled up towards the stands, you can just go to each box and change the angles, without having to run control lines between them.

Couldn’t you also do this using beam steering?

Beam steering has benefits, but also drawbacks. So instead of going down the beam steering avenue, we’re doing more advanced aiming, but using the physical space. Of course this also leaves the door open for additional beam steering, although we’re not using that right now.

We wanted to get rid of the old cumbersome rigging where people’s fingers are between cabinets. And we have all seen a lot of systems go up and then come down in a not-the-most elegant fashion. We wanted go straight to a system where you didn’t have to fuss with all of that and just had to fly the cabinets straight up and adjust it after it has been flown.

And technologies like beam steering can be applied gracefully and elegantly, but you can hear it when it’s used drastically.

How does the remote control of horizontal dispersion work in the Trinity system?

There are some systems you can control manually in the horizontal plane, like the [L-Acoustics ] K2, where you can manually adjust the horn flare in three settings, but ours is continuously adjustable from 60 to 120 degrees — either symmetrically or asymmetrically, in ten-degree increments — five degrees per side.

There are other systems that are offered in many separate cabinet versions with different dispersions, say as an 80-degree or 120-degree box. We wanted to something that hadn’t been done before. And our incorporation of the adjustments in the horizontal plane is also unique.

There are linear actuators behind the horn flares on each side and these physically change the angle of the waveguide to control dispersion.

We all know that the top boxes need to project further and need more narrow dispersion than the bottom boxes. The Trinity system gives the user the ability to gently change dispersion between boxes from the bottom to the top of the array. Or you may be in narrow room and forced by the lighting guys to hang the system near the outside walls.

We have asymmetric control so you can turn the whole sound field inward, or the system can be used to avoid balconies or other architectural obstructions. We wanted to give users more tools — not only for preplanning, but also as a live, iterative process.

Besides actuators, what components comprise the Trinity system?

Trinity is a four-way cabinet with two rear-vented, horn-loaded 12-inch drivers in the low frequency section. The mid frequency section are four 6-inch transducers loaded on our patent-pending Coherent Midrange Integrator (CMI) waveguide.

In developing a waveguide that can be continuously adjusted, we had to completely rethink the exit aperture of the six-inch transducer that’s on the waveguide.

The coaxial high frequencies are similar to a standard coaxial driver but consists of two high frequency drivers with ring-diaphragm compression drivers and the large diaphragm playing from 800 Hz to 7 kHz and then a small diaphragm from 7 kHz up. The high-high frequency is behind the low-high driver and fires through the center of it. It’s really similar to a cone-and-compression driver coaxial arrangement.

These coaxial midrange drivers are mounted symmetrically on either side of the high frequency exit, just as the six-inch drivers are mounted on the horn flare of the waveguide and exit in the throat of the waveguide.

So what are some of the Trinity experiences based on field tests?

We’ve had a full system on multiple tours for the past year. One of the first outings for the system was in a typical ballroom setting, with a large dance floor and a balcony above it with the balcony face. It wasn’t a huge tour, but they were doing 50 dates in places where it’s hard to get 3-D plots in a lot of those venues.

After hanging it, there was a significant reflection from the balcony face. With an old-style line array, you’d have to take it down and refly it — or just deal with it — but in this case, the system tech on the show utilized our remote software and changed the angle on the second and third boxes and it was fixed.

So besides showing at InfoComm 2015, what’s ahead for Trinity?

After having Trinity on multiple, successful tours for the past year, we’ve begun taking pre-orders for deliveries in Q1 of 2016. Our official launch at InfoComm will coincide with a live showcase at Electric Daisy Carnival [June 19 to 21, 2015] in Las Vegas — a 130,000-person show. We are incredibly excited for the world to experience the power of Trinity in action.

Read the full article here

filed under: PK SOUND, Products, Technology