Reviewer: Marja & Henk
Financial Interests: click here
Sources: PS Audio PWT; Dr. Feickert Blackbird MKII/DFA 1o5/Zu DL-103; Phasure XX-PC; NVO SPA-one Special Edition [in for review]
DAC: Phasure NOS1 DAC; PS Audio Direct Stream DAC [loaner]; PS Audio NuWave DAC [loaner]
Streaming sources: XXHighEnd; iTunes; Devialet AIR; La Rosita Beta; Qobuz Desktop, Tidal Desktop
Preamp/integrated/power: Audio Note Meishu with WE 300B (or AVVT, JJ, KR Audio 300B output tubes); dual Devialet D-Premier; PTP Audio Blok 20; Hypex Ncore 1200 based monoblocks; Trafomatic Kaivalya; Trafomatic Reference One; Trafomatic Reference Phono One; Music First Passive Magnetic; NVO ISA-2 [in for review]
Speakers: Avantgarde Acoustic Duo Omega; Arcadian Audio Pnoe; Podium Sound One; WLM Sub 12; Sounddeco Alpha F3; dual Zu Submission MKI; Soltanus Virtuoso ESL
Cables: complete loom of ASI LiveLine cables; full loom of Crystal Cable cables; full loom of Nanotec Golden Strada; Audiomica Pearl Consequence interconnect; Audiomica Pebble Consequence
Power line conditioning: PS Audio Powerplant Premier; PS Audio Humbuster III; IsoTek Evo 3 Syncro; AudioMica Allbit Consequence
Equipment racks: Solid Tech and ASI amplifier and TT shelf
Indispensable accessories: Furutech DeMag; ClearAudio Double Matrix; Franc Audio Ceramic Disc Classic; Shakti Stones; Akiko Audio sticks; Kemp polarity checker
Online Music purveyors: qobuz.com, tidal.com, bandcamp.com, amazon.co.uk  
Room treatment: Acoustic System International resonators, sugar cubes, diffusers
Room size: ca. 14.50 x 7.50m with a ceiling height of 3.50m, brick walls, wooden flooring upstairs, ca 7 x 5m with a ceiling height of 3.50m, brick walls and concrete floor downstairs.
Price of review item:  €29'750/pr (ex. VAT)



In our highlights report of the 2016 Munich High End show
, we'd called the new Grimm Audio LS1be a completely different animal. Well, different when compared to the first iteration of the LS1 music system which we reviewed here in October 2012. Four years later, the original LS1 had spawned two siblings: the down-priced LS1a and the subject of today's review. First off, the LS1 family members were and remain complete systems with their own amplification and full control functions built in. The only things still needed are a source and wall power. All LS1 models accept an XLR line-level analogue stereo signal, 44.1-192kHz digital via AES/EBU and 24bit/384kHz PCM plus DSD128 via USB.


All electronics (DSP, A/D, D/A plus amplification modules) cleverly hide inside each speaker's hollow left leg. Depending on physical location of your source, you'll configure either the left or right speaker as master which makes the other the slave. Connection between them is by CAT5 cable and RJ45 connectors. Both speakers are identical except for the role you assigned them. For power, each left leg contains a pair of 120w nCore amps. That's the case for the entry-level LS1a two-way. But the LS1/LS1be are recommended as 3-ways. That adds an upfiring subwoofer between their legs. Depending on model, the associated subwoofer amp becomes a 400 or 700-watt nCore module with matching power supply.


For drivers, the LS1 family starts with a Seas DXT tweeter and Seas woofer in the lacquered LS1a but a Grimm LS1s subwoofer can be added to that base model later. The regular LS1 already includes the subwoofer to augment its Magnesium-cone woofer and Seas DXT tweeter. This model gets upgraded nCore amps and the cabinet finish becomes Bamboo veneer. The latest addition and subject of this review is the LS1be. Whilst basic appearance and geometry remain unchanged, the same can't be said for what happened beneath the skin. Though the trusty Seas woofer with magnesium cone continues on, above 1500Hz a new Beryllium tweeter co-developed by Grimm and Seas takes over. It adds the 'be' suffix to the name. To control its dispersion, Grimm added a new aluminium wave guide. Both drivers then mount with hidden screws to a cabinet made of Hi-Macs also called natural acrylic stone [a Corian/Krion equivalent – Ed.]. Already this cosmetic refinement elevates the latest iteration of the LS1 to a higher level beyond the somewhat industrial or pro-audio looks of the LS1a and LS1. But to 'be' were yet more enhancements. Stuffing digital electronics into the left leg, jitter remains a factor. For the new flagship model, the electronics were reworked to push jitter figures even lower. This meant identifying and applying higher-quality parts and overhauling the power supplies which are now wired with silver.


But there's more than new cabinet material, invisible driver mounts, upgraded tweeter and upgraded electronics. The subwoofer itself has been seriously rethought, too. Based on a Peerless driver, the LS1s was always designed to augment the head's Magnesium woofer below 70Hz, using DSP to control phase and seamless handover via an active crossover. Bass response in a hifi system can be make or break. It should be instantaneous, free of distortion and move a lot of air. Easy? The challenges in this simple wish list are many even if they're all rooted in basic Physics. Let's go down the list. Every driver has its own resonant frequency. The exact frequency is dictated by cone mass, compliance of the cone's suspension and the air volume behind it. At the resonant frequency, the driver's output is higher than at other frequencies. That represents a response peak. When the driver's own resonant frequency occurs within its designated operating range, there will be nonlinearities and related colourations.