September 2011 Issue
Speaking of Speakers

Lake LM 44 Digital Audio Loudspeaker Processor

Lake's new LM 44 Digital Audio Loudspeaker Processor is being introduced at London's PLASA show this month. Identical in many respects to the Lake LM 26, the LM 44 is distinguished primarily by a different input/output configuration.
Inputs and Outputs


The LM 44 provides four analog input and four analog outputs, in contrast to the LM 26's 2-in/6-out configuration. In addition, the LM 44 accommodates 8-in/8-out AES3 and 4-in/8-out Dante digital audio transport. The LM 44 benefits from the latest implementation of Lake's iconic "Mesa EQ" configuration, utilizing four Mesa modules, each with an independent input mixer and output signal processing chain.


New features include Raised Cosine Equalization, both linear phase and classic crossovers, LimiterMax peak and RMS limiters, and a maximum available delay of 2 seconds.


The LM 44 completes the LM 26's ability to replace the previous Dolby Lake Processor's ability to be used in various configurations, including combinations of 2x6 Contour and 4x4 Mesa EQ, by now offering both types in fixed format products that aren't reconfigured with I/O cards, but are mixed and matched by rack-mounting and plugging XLRs, or, in the case of digital I/O, DB-25 or Cat5 connectors.


Multiple Uses


With this configuration, the LM 44 is well-suited for a wider number of different FOH applications. These include use as a mix-matrix and full system EQ - sitting between a mixer and virtually any high-end performance loudspeaker system - switching amongst consoles on large events, inserted EQ for monitor systems, FOH to stage digital transmission, line driver for self-powered systems and as a Dante break-in/break-out box.


With its 4 × 4 input configuration, one or more LM 44 units can replace the now-discontinued Dolby Lake Processor in most applications. It also serves as a scalable alternative to other larger and more expensive processors in situations when only a 4 x 4 analog I/O configuration (or multiples of this) is required. Though the DLP's front-panel round sci-fi Portal meters are missed, the user interface on the Lake Controller software is identical.


As with its sibling, the LM 26, all the features found in the prior generation of Lake processors remain accessible in the LM 44, including Mesa EQ filters, Linear Phase crossovers, AES3 connectivity, analog I/O with Iso-Float and Dante networked digital audio.


A Familiar Look


Those familiar with the LM 26 front panel will notice very little difference with the LM 44 except that the row of eight illuminated square module I/O mute buttons and 5-segment LED metering is now 4x4 instead of 2x6.


Like the LM 26, it has dual redundant Dante networking, GPIO connectivity and new routing capabilities with dedicated pass-thru input routers to provide true Dante break-in and fail-over functionality.


Two pairs of software-configurable General Purpose Input Output (GPIO) connections are available on a DB-9 connector, so that external devices like alarms can trigger mute, or preset recall functions, and status and fault conditions can be reported externally.


A similar front panel includes a daylight-readable display, dedicated Module Input and Output mute buttons with LED, dedicated Module Input and Output LED Metering, and dynamic buttons and rotary encoder for parameter adjustment.


New Functionality


The LM 44 accepts audio signals as analog, AES3 digital, or via Audinate's Dante digital audio network at 48 kHz and 96 kHz sampling rates. Automatic input priority switching may be enabled, and the unit can serve as both an input matrix mixer and Dante break-in and break-out box.


Analog inputs and outputs use Iso-Float ground isolation, which provides electrical isolation from an analog source comparable to transformer-based designs.


The 96 kHz internal sampling frequency employs 24-bit conversion and a 32-bit floating point internal data path. Offering a bit more than the LM 26, a single DB-25 connector provides eight channels of AES3 input, instead of four, and eight channels of AES3 output, with sample rates to 192 kHz supported.


Gigabit Dante supports sample rates of 48 and 96 kHz. Redundant Dante dual-network topology can be created by connecting all secondary network connectors to a separate Ethernet switch, ensuring full redundancy in the event of a network component failure.


Within the Lake Controller software, Super Modules allow control of multiple Modules of the same type, distributed across multiple units, as a single entity. Changes made in the Super Module are replicated across all assigned Modules for system-wide configuration with fewer on-screen icons.


Networking Options


As with the LM 26, 100 Frame Presets can be stored on the LM 44. Within Lake Controller, the System Presets function allows entire system multi-unit configurations to be stored and recalled across a network of LM 26, LM 44, PLM and legacy Mesa Quad EQ, Contour Pro 26, and Dolby Lake Processors. This allows quick switching system-wide configurations as minimal data is sent to the Processors.


The LM 44 is destined to become an industry standard and a staple of FOH racks.