Gloria

This review first appeared in November 2024 on fairaudio.de. By permission of the author, it is hereby syndicated from the German original to reach a broader English audience. Ed.

Reviewer: Ralph Werner
Analogue sources: SME Model 15 & 309, Denon DL-103R, Dynavector DV-20X2H, Transrotor Figaro, Shelter 201, Flux-Hifi needle cleaner, VPI HW/16.5 record cleaner
Digital sources: Rockna Wavelightm Antipodes K22 G4, Pink Faun LAN isolator
Preamplifier: Electrocompaniet EC 4.8MkII, Pass XP-12, BMC Audio MCCI Signature ULN phono
Power amplifiers: Electrocompaniet AW 800M, Pass Labs X250.8
Speakers: Acapella BassoNobile MkII
Cables: Dyrholm Audio Phoenix, fis Audio Studioline, Boaacoustic Blueberry Signal, Vovox, Audioquest Cinnamon and Vodka 48, Boaacoustic Silver Digital Xeno USB, fis Audio Magic LAN, Wireworld Series 7 Starlight Gold coax, fis Audio Blackmagic and Studioline
Rack: Creaktiv Trend 3 on bFly Audio b.DISC spike mounts, Stack Audio Auva EQ isolators
Accessories: Audes ST-3000 Power Conditioner (isolation transformer)
Listening room: 40m² with 2.45m ceiling
Review component retail: €13'800/pr

Off the shelf? Nein, bitte nicht! The term 'manufacture' may be overused but for Berlin-based company Klangheim, it fits like a glove. Not only can their loudspeakers be customized, assembly and installation at the customer's location are part of the concept for a focus not on mass production but more bespoke work. In fact Jörg Weber, owner and boss, founded Klangheim—the home of sound—10 years ago to offer personizable speakers. This was prompted by his time as senior engineer at California Audio Technology in the 2000s, a brand which did exactly that. But if a single product must bear all R&D costs, it naturally becomes very expensive. Hence the idea to appeal to a somewhat broader range of buyers with a few standard models. Of these, we look at the smallest floorstander called Gloria though calling it 'standard' seem an ill fit. The height is 1.08 meters, the front baffle a mere 20cm wide but the rear 28cm. Enter a trapezoidal cross section. The external design alone is unusual. Gloria stands on a wooden plinth and her matching baffle is 3cm thick. If I didn't miscount, there are 48 available Nextel colours for the body and 20 different species for the wood parts. Everyone should find a happy combination to suit their interior décor. I was particularly impressed that the wooden baffle is oiled to feel nice especially in combination with Nextel's soft-touch paint. Not only do the trim options look as we want, tactile feedback too is lovely.

A few baffle-wood samples.

Why the trapezoidal shape? Several reasons. They wanted a slim baffle and certain cubic volume. What's more, the shape avoids parallel side walls to diminish standing waves although this is likely negligible in the corresponding frequency range. Above all, it creates rear space for 18cm wide passive radiators. There are three per side while three classic 13cm mid/woofers work the front. The passive radiators install inverted to be easily loaded with different weights and alter their tuning frequency to room and taste. These auxiliary radiators from Wavecor are adapted to Klangheim's specs with a slightly lower mass and looser suspension than the stock version and screwing on additional weights has become far more convenient. Passive radiators are something like an advanced bass reflex solution without port chuff which here allows the owner to tune the resonant frequency of the mass-spring system which is the combination of front drivers, box volume and radiators on the back. Gloria arrives with three sets of 6 weights, corresponding screws and an Allen key. How this affects the sound will be discussed later.

First the 'active' front drivers. The three beer-mat-sized units are by Eton and sport their signature Hexacone material, a honeycomb-shaped core between two aramid skins forming a triple sandwich to optimize the stiffness-to-weight ratio. The d'Appolito-lookalike twins bracketing the tweeter operate from 25Hz (-3dB) to 1.5kHz so across seven octaves augmented by the passive radiators. The lowest driver however works as pure woofer just below 100Hz, making this a 2½-way array. Jörg Weber likes the slightly larger 34mm SB Acoustics ring radiator for its superior radiation pattern well beyond 20kHz. To eliminate acoustic interference from his LF, the tweeter occupies its own chamber. So does the crossover to minimize exposure to varying air pressures inside the cab triggering microphony. The imaginary square around the screws surrounding the single-wiring terminal frames this chamber. The crossover adopts 2nd-order slopes yet Weber claims "time-coherent and symmetrical" behaviour when added to the drivers' acoustical roll-off. Symmetry was required because the foil inductor decoupling the woofer was not technically feasible at the needed size so two coils in a symmetrical array combine to achieve the desired value. The selection of parts and final tuning of the filter network was preceded by extensive listening tests and although the structure is a PCB, the connection lugs of the parts solder together on the conductive traces which pays off in better sound. Noblesse oblige, this involves silver solder which also appears with the driver hookup wiring which isn't run of the mill but high-end product from Supra Cables. The binding posts are WBT.

Mass-loading weights for the passive radiators.

Back to Gloria's housing, it might seem a bit strange that the woofer and mid/woofers operate in only 23 litres. Why didn't Herr Weber move his single-wire terminal and crossover to the very bottom to gain perhaps another 10 litres? One, the passive radiators decommission that need. Two, Weber had other plans for the bottom. See the silver nozzle beneath the terminal? It's an opening to add mass loading with sand. Shipping this chamber empty is easier on the freight bill but once in situ, the hidden vault can take about 10kg of quartz sand to lower Gloria's centre of gravity. We did before/after listening sessions and believe me, you won't want to leave the sand box which makes the sound clearer and more precise. But it's not just sand which minimizes the resonant behaviour of the cab. Its material mix pays off too, explains Jörg Weber. His enclosure is 22mm MDF bonded over a large area with 7mm bitumen panels. The 30mm solid-wood baffle mounts on a 4mm thick felt damper. The same happens on the back. Here too the housing meets a layer of felt that damps another 16mm MDF panel. The combination of different materials with correspondingly offset behaviours is intended to prevent the housing from having any self resonance.