Next to being the first loudspeaker system that has been built from scratch with FIRmaker steering in mind, the K-array KH8 offers a range of other, interesting features that join well with the fully digital concept. Boxed with three units in a straight frame, the KH8 is flown effortlessly without the need for curving. Instead, the vertical aiming of each element of the flat hang can be adjusted easily and at any time while the whole system remains straight, never taking up more depth than roughly a foot in total. Shaping of the wave front, all beam steering and coverage optimization is done electronically by FIRmaker calculated filters, giving total control to the system technician on site.
When K-array first approached AFMG with the idea to electronically optimize a sound system this matched perfectly with the research that the German software company had been doing for the past years. AFMG was able to supply the ground-breaking, patent-pending optimization algorithm FIRmaker and provide a complete interface for the unique concept of a new sound system presented by K-array. Thus, the KH8 system has been designed to not only deliver high performance and maximum ease-of-use but to ultimately utilize the great flexibility provided by FIRmaker optimization.
The AFMG FIRmaker Technology in combination with the K-array KH8 system and the Powersoft Armonia control software provide a powerful basis for an efficient workflow and highly flexible setup that can easily be adapted to every new venue it is taken to. AFMG’s EASE Focus 2 software allows simulating and configuring the setup during pre-production. After a quick check on location, the FIRmaker plug-in within EASE Focus takes only seconds to calculate optimized FIR filter sets for each of the DSPs inside the full KH8 system. These are then transferred directly to the Armonia platform to be uploaded into the KH8’s DSPs. Thus, tailoring the system’s coverage to the venue is a matter of a few minutes.
Benefits of FIRmaker
“Put your sound where it belongs!” is the claim AFMG raises for its FIRmaker Technology. In fact, the secret behind this patent-pending algorithm is as simple as it is powerful. AFMG makes use of the FIR filter technology available in most modern DSP controllers to minutely control the superposition of all sound waves produced by the individual sound sources of a loudspeaker system. Because this approach relies on AFMG’s award-winning GLL loudspeaker definitions that include high resolution, 3D data of each sound source, the algorithm can also operate in 3D all around a loudspeaker system.
By this, the software company from Germany was able to include a plethora of functions and, most importantly, make these available directly to the users of FIRmaker enabled speaker systems. With FIRmaker it is possible to “design” the coverage that a system provides onto the exact audience areas. More than that, the technology does so for all frequencies resulting in a smooth frequency response in every seat of the house. If, in a given setup, feedback problems occur on stage or a corrugated iron roof produces irritating reflections, FIRmaker can also help. By simply defining the roof or stage as “avoidance areas” in the EASE Focus 2 software, FIRmaker will calculate a different set of FIR filters typically delivering 6 to 8 dB less SPL in the problematic places!
K-array KH8 and FIRmaker
K-array has been known for innovative loudspeaker solutions like the KAN200 “Anakonda” flexible speaker array. Now, the KH8 takes the next step in innovation, incorporating the thought of full digital control. Stefan Feistel, managing director of AFMG declares, “K-array have been the first to approach us, with the concept of the KH8 already in mind. The degree of control they thought of already made in-depth use of our FIRmaker Technology. From that point on, our cooperation has been driven by a common understanding. We all wanted to take the concept further to create a turn-key solution unseen by the market so far.”
The Ahnert Feistel Media Group (AFMG) introduced the new software FIRmaker in April 2013, during the Prolight+Sound show in Frankfurt, and immediately the results were felt across the audio industry. Loudspeaker manufacturers can employ FIRmaker to give their customers the option of tuning DSP FIR filters to every possible venue within seconds. FIRmaker is developed and distributed by Ahnert Feistel Media Group, located in Berlin, the same company responsible for the industry standards EASE and EASERA software for acoustic simulation and measurement as well as their related products EASE Focus, AFMG SysTune, EASE Address, EASE Evac, AFMG SoundFlow, AFMG Reflex and EASE SpeakerLab.
Technically speaking, FIRmaker represents a highly sophisticated optimization algorithm that is designed for computing optimal FIR coefficients tailored to each venue. Based on input data describing location geometry and sound sources, AFMG FIRmaker computes optimal filter transfer functions that can be automatically converted to FIR filters. Extremely precise, FIRmaker provides exact sound system coverage and SPL, offering easy on-site tuning within minutes with any loudspeaker array, existing or new.
The FIR approach
With the increase of DSP processing power, FIR (finite impulse response) filters have become widely adapted by loudspeaker manufacturers to design system-specific filter sets. FIR filters allow extensive and very fine-grained system tuning and, more importantly, they allow independent control of frequency response and phase. This has not been possible with other filters before.
Manufacturers usually invest large amounts of time and energy into the design of their system specific filter sets. Unfortunately though, such filter sets are specific to a system and do not incorporate the demands of the venue since this can be different from day to day. FIRmaker changes the process of FIR filter design, applying highly sophisticated algorithms that take only seconds to calculate optimal filter sets for a system, calculating a linear frequency response as well as a custom target curve, where sound can be electronically steered directly into the audience while maintaining the same frequency response throughout all the audience areas. And the complete radiation behavior of the system can be changed electronically without touching the rigging or setup with the simulation of the system response providing an immediate preview of the results, even before the filters are generated and loaded.
The user remains in control of all parameters, makes the final decision on which filters to implement and can, afterwards, continue to use all his previous tuning instruments. In simple terms, FIRmaker offers more flexibility and more control, not replacing classical sound system design but enhancing it, in a very powerful way.
While FIRmaker algorithms are a very complex topic, the optimization approach of FIRmaker is straight forward, simple and quick to handle by basically anyone. All that is needed for a FIRmaker optimization is the high quality loudspeaker “GLL” data provided by the manufacturer of the system; configuration of the exact system setup provided using for instance the EASE Focus 2 software; detailed layout of all audience areas in the current venue, areas to exclude, priorities for system SPL or venue coverage, again all provided by the user with EASE Focus 2. FIRmaker will calculate the optimal FIR filters for the system and immediately provide a preview of the resulting system response for the user to evaluate and base his decision.
Since the new FIRmaker technology was introduced, several companies in the industry have already adopted it. A key AFMG partner is Lab.gruppen, who combined this technology with their Powered Loudspeaker Management platform (PLM Series). Another example is Italian amplifier manufacturer Powersoft, who integrated loading of FIR filters directly into Powersoft’s amplifiers and the DSP4 module for powered loudspeakers. VUE Audiotechnik and ESS Professional Audio from Hua Nan in China, also decided to license FIRmaker for use with EASE Focus 2.
The number of FIRmaker-enabled DSP platforms is also rapidly growing.