Grimm Audio LS1 and LS1s speaker systemReviewers' ChoiceYou can say many things about the Grimm Audio LS1, but not that it is ordinary. What is the Grimm LS1? The easy but incorrect answer is to simply say that it is a loudspeaker. Actually, it’s an all-but-complete audio system that includes analog and digital interfaces, digital crossovers, amplifiers, and speakers. To play music, the only other thing you need is a source component.

The design of many of today’s speakers is dictated by how they will appear -- including whether or not they look like “high-end” components. However, the LS1 was mainly designed by Bruno Putzeys, the man behind the Hypex and Mola-Mola brands -- someone with a solid technical background who seems able to balance the various priorities of loudspeaker design. Nothing in the LS1 seems to have been left to chance, or dictated by anything but solid engineering.

Most speakers today have a narrow front profile and considerable depth, but the Grimm LS1 ($29,900 USD per pair) is tall, wide, and shallow: 45”H x 20.3”W x 6.25”D. Included in that height are the speaker’s two legs, which house the DSP crossovers and amplifiers. The cabinet is available in veneers of Light or Dark Bamboo, or in Corian. A separate, optional bass unit, the LS1s, goes on the floor between the legs. The result is a very efficient construction that I think is quite beautiful.

The LS1’s 1” tweeter and 8” midrange-woofer are both made by SEAS. On the backs of the legs are analog and digital inputs and a high-quality digital master clock, all made by Grimm and enjoying a high reputation in professional-audio circles. Inside the legs are a powerful DSP engine and a pair of class-D amplifiers: two 120W amps, very closely related to the Hypex Ncore products, for each speaker driver; a third amp, contained within the LS1s subwoofer cabinet, is based on the more standard Hypex UcD module and delivers 400W.

The LS1s subwoofer ($9995/pair) consists of a 10” Peerless woofer with a phase-corrected crossover set at 70Hz. The LS1s sits elegantly on the floor between the legs of the LS1. Placing the woofer on the floor is a smart move -- it rids the system of the very common loudspeaker problem of the transfer of a woofer’s vibration to the main speaker elements, and the acoustic support of the floor greatly enhances the sub’s efficiency.

A PC or Apple Mac computer with USB output is needed to properly set up the Grimm system, but is not required for actual use. Included with the system is an LS1 remote control and associated USB interface, to permit a variety of ways to set up and connect the LS1, including analog (XLR) and digital (AES/EBU or S/PDIF, USB) inputs. The setup software lets the user set a speaker excursion limit, as well as set the angle of the speakers in front of the listener at 30 or 45 degrees (recommended and explained in the owner’s manual).

I connected the LS1 speakers via the Grimm interface using either the S/PDIF or USB outputs from a dedicated PC running Windows 7, and JRiver Media Center 19 with a number of system tasks disabled. I ended up doing most of my listening through the PC’s USB output.

I could go on at some length about the technical aspects of the LS1 and LS1s; those interested in the LS1’s design should read the white paper on Grimm Audio’s website, though this paper describes the LS1 without the LS1s sub. Anyone interested in speaker design should read this paper -- it blows away a lot of design mystique like so many cobwebs.

When I listened to the LS1 speakers without their subwoofers, it made for very satisfying listening indeed, and would save you $9995. However, I definitely preferred the substantially greater headroom and near-perfect integration with the LS1s subs (total: $39,895/pair).

Grimm Audio LS1s

Although Bruno Putzeys played a major role in the development of the LS1, he is now focused on the very exciting Mola-Mola amplifier products. I recommend the very interesting interview with Putzeys published here last March and April: “Searching for the Extreme: Bruno Putzeys of Mola-Mola, Hypex, and Grimm Audio -- Part One” and “Part Two.”

The Grimm LS1s chez Jørgensen

In two listening sessions at the High End 2013 show, in Munich, I was deeply impressed with the LS1-LS1s. Despite listening conditions at shows being less than optimal, I heard neutrality, and the ability to simply play music beautifully.

Setting them up in my living room proved to be an altogether more complicated affair. Initially, I would have expected a narrower, more forward dispersion pattern to be less dependent on the room acoustic than my much more traditional and aging DALI Grand Divas. Still, I had problems with a hardness that must have been the result of too much sound bouncing off the room’s sidewalls.

I found two solutions. The first consisted of Matthias Aerts, Grimm’s distributor for Belgium, who brought along a number of absorbers, which we placed along the sidewalls, three per side. Aesthetically they would not be acceptable long-term, but my wife, who gives me a good bit of freedom in this regard, tolerated their presence for the duration of the Grimms’ stay with us. This setup allowed me to listen in the farfield from a distance of about 12’ 5” (3.5m), as I usually do.

The second solution consisted of moving my listening seat into the Grimms’ nearfield. This resulted in me listening to the speakers in a more or less equilateral 8’ 2” (2.5m) triangle. The speakers were angled at 45 degrees, their axes crossing a bit in front of my listening position. Ultimately, this arrangement gave me the most satisfaction, and that’s how I did most of my listening.

Nearfield listening is controversial. Some audiophiles claim that it sounds too much like wearing large headphones, others that it’s the best thing since sliced bread. Generally speaking, in the nearfield a listener will hear a lower ratio of room sound to the sound coming directly from the speakers. For many listeners -- especially those whose rooms supply much of the perceived soundstage’s width and depth -- this can be disconcerting. With an essentially neutral speaker like the LS1, it could be exhilarating. I could easily understand why serious audio professionals are enthusiastic about this speaker.


A few months before the LS1-LS1s system was delivered, my wife and I visited Avantgarde Acoustic’s splendid new showroom in Lautertal-Reichenbach, Germany. One thing that greatly impressed us there was the clean, visceral reproduction of “Magic Bus,” from the Who’s Live at Leeds (16-bit/44.1kHz AIFF, Polydor) -- in my opinion, one of the great live rock recordings of all time. This was a €100,000 horn system playing in a large listening room, and it was truly memorable.

When I played this track loudly at home through the Grimm LS1-LS1s, my listening experience was of equal intensity. I had never had a system in my house that could play loud rock so purely and cleanly. No overdriving of the room, no room roar -- just very clean, with the grab-you-by-the-seat-of-the-pants sound of live rock. Do clean and loud sound contradictory? Often, we distinguish between systems that can play loud and those that play beautifully at much lower levels, because systems that can play really loud often can do so only by paying a price in heightened coloration and loss of finesse.

Not the Grimm LS1-LS1s. I wasn’t able to make them misbehave in any way, regardless of the music or the SPL. During the much-too-short period I had the speakers in house, I threw at them anything I could imagine: rock, baroque, pop, folk, country, large-scale symphonic, and ancient music, as well as small-combo and big-band jazz. You name it, I played it. So did the Grimms. I played rock albums such as Live at Leeds and Who’s Next (16/44.1 AIFF, Polydor), and loud jazz-fusion like Return to Forever’s Romantic Warrior, which can still get my juices flowing. I also enjoyed “chamber jazz” from Lars Danielson and Leszek Mozdzer, from their albums Pasodoble (16/44.1 AIFF, Act) and Tarantella (16/44.1 AIFF, Act). The Grimms brought out the best from Youn Sun Nah’s Same Girl (16/44.1 AIFF, Act) -- outstandingly beautiful music that’s somewhere between jazz, pop, and I don’t know what. What a voice, and what interesting arrangements. But regardless of the music, the Grimms played it clearly and neutrally, and equally well at volume levels low or high.

Grimm Audio LS1

I listened to several recordings of baroque music led and played by Jordi Savall, including the absolutely gorgeous Tous les Matins du Monde (16/44.1 AIFF, Alia Vox), the soundtrack to Alain Corneau’s film of the same title. The clarity, and the natural acoustic of the space in which the music was recorded, were very obvious and beautifully reproduced by the Grimms -- and even though every detail seemed to be clearly presented, I experienced no listening fatigue.

I often use Nojima Plays Liszt (16/44.1 AIFF, Reference) in reviews, not just for the music and Minoru Nojima’s spectacular performances, but also for the very typical sound of the Hamburg Steinway grand piano used in this recording. Again, the neutrality and clarity of the Grimm LS1-LS1s system resulted in one of the best reproductions of this recording I have ever heard.

Beethoven’s Symphonies, with Nikolaus Harnoncourt and the Chamber Orchestra of Europe (16/44.1 AIFF, Warner Music) or Osmo Vänskä and the Minnesota Orchestra (16/44.1 AIFF, Bis), also got serious playing time. So did a collection of French and Russian music with Sergiu Celibidache conducting the Munich Philharmonic (16/44.1 AIFF, EMI Classics/Warner Classics). Indulgences also included Saint-Saëns’s Symphony No.3, “Organ,” with Eduardo Mata, the Dallas Symphony, and organist Jean Guillou (16/44.1 AIFF, Dorian), as well as the old warhorse Pomp & Pipes!: Powerful Music for Organ, Winds, Brass & Percussion, with organist Paul Riedo, and Frederick Fennell leading the Dallas Wind Symphony (16/44.1 AIFF, Reference). That last one blew my socks off though the Grimms, without the LS1s making any false move -- the bass was always well integrated and tuneful.

Grimm Audio LS1s

Two of my favorite torture tracks are “Fanfarra” and “Magalenha,” from Sergio Mendes’s Brasileiro (16/44.1 AIFF, Elektra). This album, or several songs from it, have accompanied me to audio shows for almost 20 years now. This wonderful music demands the best amplifiers and speakers -- imagine singers not being drowned out or even severely modulated by as many as 100 drummers banging away -- and the Grimms never sounded congested or challenged by the complexity.

The Grimm LS1-LS1s played all sorts of music spectacularly, including old and new recordings, music that was not very well recorded, and much that was. Despite the Grimms’ very real ability to reveal a recording’s warts, these rarely sounded bad enough that I wished to press Stop and put on something better sounding. This strikes me as an incredible bonus: a speaker system that lets you hear what’s really on the recording, but makes it possible to enjoy the vast amount of interesting music that has not been well recorded. I’m still trying to figure out how Grimm has gotten away with this.

To flavor or not to flavor

In audio today, a schism exists that extends all the way through the high end and into the extreme high end: the dilemma of whether you should attempt to accurately present what is actually on the recording, or flavor it to your taste and thus make it more enjoyable to listen to. We all know that it’s useless to discuss taste -- no one but you can be the arbiter of what you might like or dislike. Some speaker designers strive for a rationally balanced sound, while others provide the flavor they like, or that their customers want to buy. Thus, many purveyors of high-end equipment, especially speakers, make systems whose sounds are inherently colored. It’s true that anechoic frequency response by no means fully describes a speaker, but a balanced frequency response in-room is absolutely necessary for uncolored reproduction.

The Grimm LS1 system is designed to deliver this in a room that is not too reflective. It is not designed to “fix” a room that has a difficult acoustic. This means that you must ameliorate your room’s acoustic problems -- and virtually all rooms have such problems -- by other means, such as proper speaker positions, and absorption and diffusion treatments.

Many expensive high-end audio products are advertised as being “no-compromise” designs. This is, obviously, a complete fallacy. There are always compromises. The art of speaker making lies in the ability to choose the best balance of compromises. The LS1 and LS1s excelled at providing an honest and very rational set of choices and compromises in how to produce a world-class speaker system.

Can we come to a conclusion?

The Grimm Audio LS1-LS1s combination is a true recordist’s tool that can give a studio engineer deep insight into a recording. For this, it has received strong accolades from professionals in the recording business. At the same time, it lets the music lover at home better enjoy less good, even bad, recordings than any other speaker system I have ever used.

These days, I find it less and less interesting to try various components in my system; I much prefer to listen to music. Other audiophiles, to stay happy, need something to fiddle with all the time; this is not the system for them. The Grimm Audio LS1-LS1s let me get down to excellent listening for a good long time with no fiddling whatsoever. That’s my kind of speaker system. You do need a good source and a room whose acoustics have been properly addressed. But that’s it.

For most of us, the cost of $39,895/pair is not peanuts. In fact, it’s a lot of money -- but compared with other offerings, I do not for one second think that the Grimm system is overpriced. It is an honest and thoroughly well-designed loudspeaker system -- a world-class reproducer that offers excellent value.

You can’t argue about taste -- I can imagine someone missing a bit of coloration here or there -- but I found the Grimm LS1-LS1s system the most neutral and, overall, highest-performing speaker system I have ever tested. It was with more than a little regret I that I watched them depart.

. . . Robert Jørgensen

Associated Equipment

  • Speakers -- Rogers Reference Monitor (LS3/5a with purpose-built 12” woofer system and electronic crossover), DALI Grand Diva
  • Digital sources -- Custom-built PC with RME Hammerfall DIGI9652, Steinberg UR22 USB audio interface, and Lynx Two, running Windows 7, JRiver Media Center 19; M2tech hiFace USB-to-S/PDIF digital converter
  • Analog sources -- Linn Sondek LP12 turntable with Syrinx tonearm and experimental van den Hul cartridge, B&O Beogram 4000 tangential-tracking turntable
  • Amplifiers -- Esoteric Audio Research 509 monoblocks, Gamut D-200, Lyngdorf Millennium Mk.III, TacT RC 2.2X
  • Preamplifier -- Esoteric Audio Research preamp and MC transformer
  • Cables -- Isoda, van den Hul

Grimm Audio LS1 Loudspeakers and LS1s Subwoofers
Prices: LS1, $29,900 USD per pair; LS1s, $9995/pair; $39,895 total.
Warranty: Five years parts and labor.

Grimm Audio
Strijpsestraat 94
5616 GS Eindhoven
The Netherlands
Phone: +31-40-213-1562


US Distributor:
GTT Audio & Video
Phone: (908) 850-3092