28 Digital Active

With their fully active LS1 Grimm Audio throws many familiar conventions overboard and achieves a superb signal fidelity by means of switching and DSP-controlled crosso- vers. User comfort and neutrali- ty are on world-class level. For Head AND Heart 30 Loudspeakers Digital Active

Author: Wolfram Eifert amplifiers which occupy the left speaker cases will be done only once. But the base. Likewise it would make little sense software can also replace the jogwheel to dabble at the internal wiring between armed controller and thus elevate the espite or simply because of their chassis and power amps. This underta- Mac or PC to a command centre. Dultramodern digital signal proces- king would not only be tedious, but also Although DSP filters can modify the sing Grimm Audio’s LS1 are easy to con- yield a fat lot. response characteristics of a trol. All relevant settings can be done Tinkerers should see the plug & play in virtually any desired way with the sui- using a computer or – haptically way character as a chance and use the time table programming, company founder more appealing – via the included con- thus saved otherwise. Especially since Eelco Grimm only makes use of the bles- troller. But also in other respects the first digitally controlled speakers offer plenty sings of digital technology where he can’t sound transducer from this young Dutch of optimisation potentials, too. Improve- get ahead on the mechano-acoustical company appears to be utterly smart. ments of the room are virtually level. The frequency and time behaviour Active speakers with their onboard always possible, just like the expansion are therefore perfected first with conven- amplifiers are old hat, however besides of your record collection with both sound- tional means and only refined digitally Viewed from behind, DSP-controlled frequency crossovers the wise and artistically first-class recor- to such an extent as it makes sense in a the switching amplifiers LS1 also offers A/D and D/A converters dings. sonic and also in a metrological con- and filter electronics of the very highest quality grade. The Of course the electronics will “under- text. are mounted together in the right speaker LS1 are indeed much more than just a stand“ all common audio sampling rates Hence the software allows merely a base. The very energy- pair of loudspeakers, but rather a com- between 32 and 192 kilohertz. In spite few, yet all the more sensible adjust- efficient power amps plete gear which makes a conventional of all trendiness the Dutch will leave no ments. For instance, the user can choo- produce only little heat chain with its numerous single devices analogue fans out in the rain. Vinyl con- se how much he wants to angle the spea- and therefore need no and cables look quite cumbersome. noisseurs and other conservatives will kers, how strong the bass shall play special heatsinks or For studio users, who have sworn by find the suitable input in the base, with compared to the rest and if the maximum fans. The have active designs since the year dot without a balanced layout like its digital neigh- lower limit frequency of 20 hertz shall be separate power supplies hardly an exception, an LS1 doesn’t mean bour. Due to its completeness the system savoured to the full or only halfway. and amplifiers which a fundamental cultural change. Private relieves the user of many decisions, sa- As is typical of active speakers, a limi- are controlled from the users who have become used to custo- ving space and quite a few cables. Net- ter will detect any kind of overdrive and speaker base. mising their mostly passive loudspeakers work players are ideal sources for this prevent unpleasant distortions and hard- with the most diverse amplifiers and speaker genre, but basically a simple ware defects by temporarily lowering the cables, need to rethink, for DSP-cont- computer will do. levels. Braking actions are indicated by rolled active speakers are pretty much The software required to operate the a flashing LED. Brave personalities, who resistant to optimisation. system is provided for download on grim- prefer to listen unplugged, can deacti- The user will find nothing to adjust on maudio.com. There are clearly structured vate the protection circuit in the default the converters, crossovers and switching menus for all basic settings, which in most settings or suppress the prompting of the LED. One of the many musical pieces that ‚‚ the reviewers were demanding from the hi-res standard, but only the usual CD Technology at is finest: the measuring specs are beyond any doubt Grimm was the first movement of resolution. Over the Grimm the popular The controller has a large jogwheel for the input selection Beethoven’s Trio for Piano, Violin and work sounded extremely supple and full- “Dead straight frequency curves, excellent omnidirec- Violoncello Opus 1.1. The recording with bodied, while at the same time with fa- tional behaviour, perfect transient response: the LS1 is the legendary Abegg Trio dates from bulously natural acoustic timbres. 1987, thus from the early days of digital The classic lovers in the team – and one of the best speakers ever measured.“ technology, and consequently offers no not only those – were speechless. The illusion of a hall, including a pin- point localisation and depth of focus, ker biz mainstream. For example, the over all radiation angles and frequency was reproduced so perfectly by the cabinets are noticeably wider and less ranges. Grimm like with hardly any other louds- deep than usual. The ample baffle makes The Dutch pursue the optimisation of peaker ever reviewed by AUDIOphile. the dispersion behaviour less contingent the cabinet geometry very consciously, But why does the speaker sound so on angular patterns. By this all-rounder for DSPs can only flatten a frequency uniquely homogeneous and true-to-life Grimm, a lecturer for studio technology response efficiently if the errors occur now? Indeed, the LS1 sets itself apart in his regular occupation, hopes to achie- within a broad angular range. A similar GRIMMand for adjusting the volume level. quite obviously from the common spea- ve a markedly even energy distribution behaviour can be seen with anoma- > 32 Loudspeakers Digital Active ‚‚ lies in a diffuse sound field, which are Since even the best chassis show cer- can only be achieved through greater A dream for high-enders: the naturalness of the LS1 turns me on big time Demo-CD caused by imbalanced room acoustics. tain tolerances, every loudspeaker is cone excursions, the maximum volume For this reason they totally dispense with individually finetuned at the headquarters levels with extremely deep basses are “A grand bouquet of tonal hues, unexcited dynamics, Bert Jansch: any kind of acoustic room calibration. in Eindhoven. More technology and pro- limited accordingly. details aplenty: the best sources display their full po- The Black The lateral roundings serve to reduce duction details of the LS1 can be found With acoustic instruments, whose Swan edge diffraction effects and also help to in the spread at the end of this review. spectrum contains only faint low-end tential on the Grimm.“ smooth out the SPL curves. The drivers, The subject of amplification is handled signal components in most cases, this is Folk singer and guitarist Bert Jansch supplied by Seas from Norway, can thus by so-called Ncore switching amplifiers rarely a problem - with electronic music is no stranger to the scene. His latest cover an unusually broad sound field very from Hypex, another Dutch-based ma- it is, however. So to increase the reserves album contains 12 particularly emoti- evenly. nufacturing company. Due to their design there are custom-built availa- onal songs. The sound is marvellously The assignment of the frequency ran- layout they produce only little heat and, ble which are simply slid onto the base and hits the brick wall with electronic nature. The LS1 won‘t let you get closer intimate and yet full of energy. (Drag ges and the final linearisation is done in together with power supply and filter plate and driven from the speaker base. music. Due to their sophisticated filtering to singing voices than originally intended City, also on LP). two steps. In a first step of calculation stages, sit on a slim pc board located in The sub bass modules are equipped with one needn’t be afraid of negative effects by musicians and sound engineers, and the frequency response of the single dri- the left speaker base. 10“ long-stroke chassis from Peerless from the upfiring bass units that work it won’t open three-dimensional sound vers is equalised by DSPs, as if each of When used in passive mode, a loud­ which, like the low-mid drivers in the about two feet away from the speaker’s stages that aren‘t there on the recording. The Author them would have to cover the entire fre- speaker with the size of the LS1, which head section, have a closed-back enclo- acoustical centre. The subs perform like These speakers are neither charming nor Wolfram quency band. Hence the subsequent offers a net volume of merely 14 litres sure behind them. The woofers, too, have a perfectly integrated third way and are flattering, but honest and pure. Eifert crossover will “see“ two very broadband and a “small“ 8-inch low-mid driver, an electronic bandwidth and transient another proof of the musically correct What makes the Grimm so emotionally transmission curves and can calculate on would largely fade out frequencies below behaviour optimisation. system design. engaging and convincing is its outstan- this basis precisely mirror-inverted filter 50 hertz. But here the electronics depart- The integration of the subs does not Homogeneity and the absence of ex- ding naturalness. My personal listening slopes, so that the summation of the SPL ment provides an active feedback control necessarily produce a deeper bass, but aggerations are the hallmark of the LS1, tip would be “High Days“ from the album The graduate media engineer has curves will come off smoothly in the cross- to make her go down to 20 hertz after spares the low-mid drivers in the head not only in the bass, but in general. So “The Black Swan“ featuring Scottish folk been active as specialised journalist over zone without perceptible ripples. all, depending on the settings. Since this piece a good deal of travelling work please do not expect sound descriptions singer Bert Jansch, published by Drag which is audible by an enhanced overall applying exuberant raves or demo sounds City in 2006. His unpretentious voice and for about 20 years and knows the tranquility. Without the woofers – waiving of the hyperspecial kind. Sure, the Grimm the acoustic guitar sound so pure and scene like hardly any other. For his them will save you a full 7000 EUR per sounds wonderfully pure with a superb vibrant over the Grimm that I got goo- private chain neutrality is the leading pair – the LS1 does not sound any diffe- resolution, but it won’t depict an orches- sebumps while listening. I know you’ll be virtue. True to the motto “Feelings rent in tonal respect, but makes less fun tra as more exciting than it can be by no different. < arise in your mind, not in devices.“

AUDIOphile Character

stressless infectious airy, smooth emotional Grimm Audio Frequency Response dynamic LS1/LS1s Grimm LS1 Frequenzgang 100 dB List price: 25,000 EUR axial 10*hoch 30*seitl. Warranty: 2 years 90 dB Weight: 68 kg

Dimensions: (W x H x D): 80 dB 52 x 115 x 16 cm Finishes: Light or dark bamboo 70 dB neutral direct veneer, 60 dB authentic high-def white Corian. All specifications 50 dB incl. . 10 Hz 100 Hz 1 kHz 10 kHz 40 kHz AUDIOphile Potential The connection between speaker electro- Distributor: nics and computer is controlled via a little Audio Import GmbH The SPL curves are extremely linear, USB interface which is supplied. Herrlinghausen 43 even angles of 10 and 30 degrees AUDIOphile Advice 42929 Wermelskirchen off the main axis (red) are perfectly Phone: +49 (0) 21 96 / 88 31 36 covered. The sub-low range has a Owing to the location filters the The subwoofers sit on the base plate and Internet: cutoff frequency of 17 Hz @ -3 dB. LS1 may stand freely or close to a have their own power amps. The grey www.grimmaudio.com The loudspeaker produces peak wall. The subwoofers are extre- protective covers are detachable. www.audio-import.de levels of 105 dB. Distortion and mely helpful. Room acoustics and step response (not shown) are just source devices offer potential for as excellent. optimisation. 34 Loudspeakers Digital Active

Each speaker a Unicum With Grimm Audio every speaker is measured individually and then trimmed to per- fection. The decisive part is the programming of the DSPs.

Author: Wolfram Eifert studios in a version with longer legs. To se characteristics of the drive units. Modi- begin with, co-owner and name giver fications were controlled regularly by mea- roducts come and go, but some Eelco Grimm tries to achieve a maximum surements both in the anechoic room and Phave kind of a personal history. Our of signal fidelity with electromechanical under free-field conditions, because only editor-in-chief Bernhard Rietschel had means and uses digital technology only that way reliable statements can be made discovered the LS1 – hitherto virtually in those places where conventional me- for all frequencies. When it became obvi- unknown on the German hifi scene – at thods fail. ous that the usual measuring tools didn’t A home-made analyser delivers super The offices at Grimm Audio are remarkably bright and friendly. As is usual in precise jitter measuring values. hightech companies, the PC is the number one work equipment. the Norddeutsche HiFi-Tage in February A loudspeaker that is to sound one yield the necessary precision, they built this year and even several days after his hundred per cent neutral must radiate their own ones without further ado. One return from Hamburg was still raving its energy homogeneously over all room example is the jitter analyser shown on the quite unhumbly refers to as the world’s about the hyper natural sound he had angles and may not only show a linear followng page. metrologically best D/A converter. The heard in the Grimm suite at that HiFi behaviour within a narrow range. In order To make sure that all loudspeakers func- amplifiers of the LS1 are the result of a show. Following his gut instinct, he left to meet this requirement the 8“ low-mid tion equally perfect, the inevitable remai- cooperation with Hypex, another manu- no stone unturned to summon this ob- driver, which is pretty large for medium ning tolerances of the individual units are facturer from the Netherlands. Their pro- viously exceptional product to the edi- frequencies, must be faded out as early smoothed out by means of the DSPs. But duct development manager Bruno Putzeys torial rooms for AUDIO and AUDIOphile as 1500 hertz. For dome , which this isn’t done using the sledgehammer. is a specialist for digital signal processing as fast as possible. That his assessment again must not be too large, such a low Based on the measuring protocols specially in the broadest sense. The unorthodox was dead on, became already apparent coupling poses a big challenge, because trained employees decide where correc- switching amplifiers in the left base rest during the first review for AUDIO’s May it considerably strains the moving system. tions need to be made. After all the data on his experience. Despite all their passi- issue, where the speakers received high- After an extensive search the designers sets differ for each loudspeaker. on for facts the Dutch are also die-hard est praise from everyone who had heard found a suitable bass/midrange and The processors and converters built into music fans. If they discover a component it. dome combination from driver the LS1 benefit from the experiences with that appears to act as a sound brake, it will Indeed, there’s a painstakingly well- specialist Seas of Norway. the in-house studio DAC called AD1 that be replaced. This might even mean the conceived concept behind the LS1, which Together with the Scandinavians the enjoys a legendary reputation among pro- death of an allegedly negligible capaci- The enclosures that are purposely styled broad and flat get a sheep’s wool is also sold to professional recording Dutch thoroughly finetuned the respon- fessionals and which mastermind Grimm tor. < damping, which promises best acoustical properties.

Co-founder and mastermind Eelco Grimm answers e-mails Bruno Putzeys is responsible for the DSP programming. In Electronic parts, enclosures and chassis are prepared at A freshly mounted LS1 with white Corian enclosure is wai- in style with Mac-Book and Skywalker Sound shirt. his main job he’s the product manager with Hypex. this station for their final assembly. ting for its final measuring check.