Review: Quadral Signum 90 Floorstanding loudspeakers

Review: Quadral Signum 90 has set a self-confident signal that is presumably razor-sharp in view of the component quality.
4/5 - (1 vote)

Review: Quadral Signum 90 Floorstanding loudspeakers: Generous & groovy- The new Signum series from the traditional manufacturer Quadral should stand for high sound quality at a very low price. In view of their division into center, compact and floorstanding speakers, their use in home cinema is obvious. The top model Quadral Signum 90 would like to prove in this test that it can also convince in demanding stereo operation .

Born in the seventies and infected early with the so-called hi-fi bacillus, I almost inevitably have a history with Quadral. In 1987, one of two serious dealers in the small town where I originally come from put a pair of huge monoliths in the shop window with a nameplate of Titan III. I heard a divine echo of thunder in my youthful atheist heart and at the same time felt something like a pain when I squinted at the price tag on the floor. In the weeks that followed, I pressed my nose against the pane that separated us or went into the shop more often than usual. As a concert organizer of the youth center I always had posters to hand out and as a record collector you were also welcome in the shop, there was also a used corner, which had to be inspected regularly. Nevertheless, my constant presence was noticed and, upon polite request, I got a listening appointment with the “Quadral Titan”. Today I understand very well that nothing about the young punk indicated a potential customer and I can appreciate the noble gesture of the shopkeeper better than then.

That was the free promotion of young talent from the specialist trade and gave me an unforgettable afternoon in the sound bath flooded with open sluices – I still cite this experience today when I am embarrassed about having to define perfect happiness. A little later I bought three-way speakers from a competing manufacturer with a bulldog in the logo from the second-hand department. Both shops no longer exist – another, rather sad story. But Quadral still exists and the brand continues to rely on specialist retailers, which, as stated, means more than negotiating margins and moving pallets.

Saver buns?

As a specialist editor, on the other hand, I’ve never had anything to do with Quadral and was actually very happy about the pair of Signum 90s, even if the largest floorstanding speakers in the new Signum series may not quite meet the standards I’m used to applying to very expensive high-end would be able to meet. Although the MDF body is foiled and only the baffle is varnished, the slim pillars make a high-quality impression, which even with a closer inspection of details such as the recessed single-wiring terminal made of plastic of decent quality and the four stabilizing arms, in one decoupling rubber layer is incorporated, is not clouded. Those who prefer spikes or other feet will also find recessed threads there. A small blemish can only be found when the housings are surgically tackled: The chassis are screwed directly into the MDF by means of countersunk screws made to match with washers. In terms of functionality or stability, I don’t see a serious defect in this, but it is an unusual type of assembly in large-scale production, especially since threaded sleeves are penny items.

Rückseitiges Bassreflexrohr der Quadral Signum 90

According to your data sheet, it is a three-way loudspeaker , but if I follow the explanations of developer Sascha Reckert, I get closer to 2.5-way, since three almost identical bass-midrange speakers run parallel in the bass, whereby the two lower, which show a higher moving membrane mass, are located in their own bass reflex chamber and only leave the top one alone at a relatively high 550 Hertz. But that’s not a crucial question for the result.

The midrange driver with bass competence shares a ventilated housing section with the tweeter, which encompasses exactly half the volume of the chamber for the two woofers and is precisely matched to their resonance frequency. From an audiophile point of view, the partition is glued in at an angle to counteract standing waves. This constellation with three woofers, which act on different volumes, presents the developer with a very demanding task, both in terms of the impedance curve and the efficiency, which is why the crossover is comparatively complex. At this point, however, I cannot see a rigorous need to economize, iron core coils With an appropriate wire diameter, decent cement resistors and resilient MKP capacitors are not necessarily common in this price range.

Die drei 18 Zentimeter durchmessenden Konustreiber der Quadral Signum 90 weisen titanbeschichtete Polypropylen-Membranen auf

The midrange driver was given a blocking circle in order to reduce excessive elevation at four kilohertz. I do not want to rate an electrolytic capacitor negatively, especially since it is parallel, where it does not cause any damage to the sound. In terms of chassis quality, the Quadral Signum 90 does not show its price, which is becoming more and more astonishing in my eyes. The three 18-centimeter-diameter cone drivers with a titanium-coated polypropylene membrane, which – you can tell from the characteristic ears – are specially made for Quadral, have sturdy cast baskets and impressive ferrite magnets. This cost of materials explains the impressive weight of almost 25 kilos per speaker – and the rated load capacity of 150 watts does not seem excessive to me. Quadral’s Signum 90 deserves the highest recognition for its workmanship and general impression of quality. This is not a product designed for quick obsolescence, but will cost the inclined buyer living space for many years.

Generous technology transfer

I haven’t even addressed the actual highlight in a double sense. A RiCom tweeter, which has undergone many years of development at the Hanover-based manufacturer Quadral, but can actually be described as a new development at the present time, sits enthroned above the conspicuously shimmering trio of drivers, like the rooster of the Bremen Town Musicians. In contrast to conventional dome tweeters , whose membrane ideally vibrates pistonically in the magnetic field, the RiCom tweeter is a ring radiator with a double bead in the form of two half-shells, the membrane of which moves in a wave-like manner like a water surface hit by a stone. Theoretically, the high frequency spectrum can be reduced in this way with reduced distortion expand, but this design is also said to have stronger bundling, which in turn does not necessarily have to be a disadvantage. From a technical point of view, the construction of the flexural wave transducer baptized Sigma is well known, but only recent developments have led to a simplification that made it possible to use it outside of the top-of-the-range loudspeakers.

Der RiCom-Hochtöner der Quadral Signum 90 ist als Ringstrahler konzipiert

The beat goes on: Sound test of the Quadral Signum 90

In the wild, the Signum 90 will probably seldom find itself in a comparable high-quality environment as is prevalent in my system configuration. A quick estimate, a meter of my Musical Wire speaker cable costs almost three times as much as a pair of the slim floorstanding speakers. Regardless of this, the three-meter high, but just under twenty centimeters wide columns stand out confidently, sometimes even coldly.

In order to soften the rubber surrounds, I preferred to let them dance for the first few days, in the sense that I prescribed them rhythmic movement, and was initially able to find that the Quadral Signum 90 is powerful and powerful in the low frequency. “Slippery People” in the cute version of the Staple Singers (album: Turning Point ) brought the gospel family, which was once very successful with the Memphis soul label Stax, a late little dance floor hit. The Talking Heads cover from 1984, on which David Byrne recorded the guitar part, works out the gospel elements with an emphasis on the call-and-response game between Pops Staples and daughter Mavis more than the original, which was just a year earlier had appeared. The driving disco-funk beat, which, like so many recordings from the time when drum computers gradually supplanted drummers, sounds a little embarrassing nowadays, unfortunately ensures that the basically very beautiful and coherent interpretation has aged about as favorably as Carrot jeans with a stonewashed look.

Nevertheless, the resilient beat comes in handy for me to explore the bass competence of the Quadral Signum 90. It is doing remarkably well – definitely on the side of the neutral demarcation line, where it is warm and cozy, it cannot deny its bass reflex tuning, but shows no tendency to boom or drone at a distance of around one and a half meters from the rear wall to thicken up excessively. A gentle emphasis on the upper bass does not interfere with the harmonious transition to the midrange. Heavy bass impulses around 80 Hertz don’t kick in briefly, but are given some space and time, which skillfully consoles the listener over the fact that chassis and cabinet sizes below 50 Hertz are gradually reaching their natural limits. Nonetheless, the Signum 90 succeeds in credibly depicting the differences between wood, skin and steel (double bass, bass drum, electric bass). Even at a higher level, it remains impulse-proof and cleanly in rhythm.

The fact that she prefers to color with thick lines than fine hair is due to her passionate nature. She prefers to integrate it instead of separating it, the overall representation of a massive rock band suits her more than counting the horsehair on a cello bow. Her profession is more physical, in the figurative sense drinkable presentation than absolute transparency or neutrality. In principle, I think that’s good, especially since I prefer a box that is fun to colorless, boring converters in this price range.

Boing bang bump chak

With Surfer Rosa , both the Pixies and producer Steve Albini delivered an early masterpiece that has not gathered dust even after more than 30 years. Few producers manage to capture a drum kit with original dynamics on tape as realistically as Albini. Accordingly, the album also quasi-programmatically lifts with a crashing, brutally dynamic drum intro to Bone Machinethat the Quadral Signum 90 suddenly presents a really tricky task. It is important to put fine ramifications in the treble in relation to coarse kicks, i.e. not to allow sound events that differ in their natural speed to drift apart. The Quadral does this remarkably well, its overall set-up appears to be from a single source. In the three-dimensional representation, the short solo comes across as wide-ranging and impressively expansive. The fact that I have heard this drum set build up from a deeper room again falls under the fine details that the Quadral Signum 90 does not put on the gold scales.

Quadral Signum 90: Anschlussterminal

In terms of coarse dynamics, the Quadral floorstanding speaker doesn’t let anything burn, the interplay between loud and quiet, between exploding creaking and introverted whispering on Where Is My Mind , it follows with commitment and verve on the foot, the proportions also seem coherent. If I miss a bit of fine resolution in the mid-range – a scratchy voice, an abruptly torn string, three-dimensional spatial offset to the second voice – it could in fact be due to the fact that the tweeter plays very transparently and thus provokes a slight difference in quality.

Frank Black’s whining, angry and always somehow accusatory vocals transports the necessary energy all the way to the top without ever annoying you. Over the past few weeks, the tweeter has turned out to be a real icing on the cake of the Quadral Signum 90. Here it shines with fine resolution, plays loosely, transparently and with great expanse. The RiCom unit does an excellent job, it sounds fresh, bright, clear and snappy, overall controlled, without suppressing screeching guitar eruptions for the sake of convenience. Over the past few years, tweeters that are too sharp and glassy-metallic have often moved me not to attend demonstrations with entry-level speakers for longer than absolutely necessary. In this respect, the Signum 90 is very cultivated and suitable for long-term use.

Langzeittauglich: Ringstrahler als Hochtöner der Quadral Signum 90

The tweeter also provides a kind of compensation for the neutral, but, as I said, not overly fine-grained bass-midrange driver, giving the reproduction a good shot of liveliness. The Signum 90 comes from the reserve, goes with Gigantic, where a lascivious Kim Deal leaves the cover of the second voice and takes over the vocal part, a step towards the listener to pick him up and pull him into the music. After a bit of rowing back and forth, I feel confirmed in my originally intuitive alignment of the tweeters towards the listening position. By turning it even more, the spatial focus becomes sharper, but the stage becomes correspondingly smaller. In the other direction, i.e. by opening up the setup, the conciseness of the treble suffers in my opinion. However, you should experiment with it, such impressions are always strongly dependent on the room and its damping, the number of listeners also plays a role. In general, the depth of the playback room benefits significantly from the distance between the speakers and the rear wall.

Parship profile

From a sober technical point of view, the Quadral Signum 90 seems to me to be uncomplicated when it comes to its playing partner. Thanks to a sufficient characteristic sound pressure of an apparently truthful 90 decibels , it can make excellent use of the modest 15 watts per channel – each one of them very athletic and soundly worth gold – of the Genuin-Straight amplifier and does not suffer even at levels that are barely suitable for renting an apartment loss of dynamics or even compression. I suspect there are still plenty of reserves for higher levels. Whereby I consider watts to be considered unsuitable for pairing prognoses with loudspeakers. Too often I’ve heard nominally more powerful amplifiers break in as soon as the impedance dropsa box only drops below the four-ohm mark in certain places. In this respect, I always advise paying attention primarily to load stability , which can usually be read off from the dimensions of the power supply unit or the output transformer. Since a combination of the Signum 90 with Class A tube amplifiers seems rather unlikely in practice (although it probably harmonized well with selected examples), I recommend a proper AV or integrated amplifier that knows how to assert itself. A slightly higher damping factor than I was able to provide with my amp should represent the bass even tighter.

Quadral Signum 90 von vorne und hinten

Need for freedom

Be careful not to use the Signum 90 disadvantageously as a near-field monitor. Since the two basses play well into the midrange, they require a generous listening distance of at least three meters in order to create a truly cohesive sound image. It also needs space for the back and side walls, just like every full-size floorstanding speaker, you should be able to keep a meter to the side and a half in the back, otherwise it runs the risk of slipping into overemphasis on the bass due to its full-bodied and warm characteristics. Of course, the stage display also benefits from the most free possible arrangement; the width and depth of the playback room can, as mentioned, be adjusted very easily via the arrangement. It is possible that the theoretically stronger bundling of the tweeter is responsible for the unmistakable feedback regarding the angle. As already mentioned, I felt that I was well served by an exact alignment to the listening position. In much larger rooms of 40 square meters or more, a slight opening may enlarge the sweetspot without noticeably losing focus. In rooms under 20 square meters, the smaller Signum 70 is probably a better choice.

Conclusion :Quadral Signum 90

I always had a lot of fun with the Signum 90 when I was able to break away from overly strict standards. She presented herself as a classic all-rounder who, with a little care, offers an absolutely complete, very closed and, thanks to her warm, full-bodied tuning, extremely long-term sound image. But also in sub-disciplines – especially in the very fine treble and in the powerful, voluminous bass – it plays above average in its price range. If you consider that as a buyer with a narrow checkout you are sometimes fed up with uncomfortably blaring metal dome, the RiCom tweeter is a real unique selling point that could easily keep up with a higher class.

In playing on the baseline, it shows itself to be very orderly, without analyzing the musical happening, i.e. emphasizing details and separating musicians sharply. I think this harmonious and binding path is right, extremely analytical listeners may have a different opinion. In the entry-level class, however, it is about conveying a musical experience. She does this excellently in pop or rock productions, even if the recording quality is not exactly audiophile. She easily manages large backdrops with an orchestra or big band and with a large overview, intimate, small line-ups are sometimes lacking a little goose bumps and spatial depth.

With the largest floor-standing speaker in the Signum series, Quadral has set a self-confident signal that is presumably razor-sharp in view of the component quality. It will undoubtedly cut a fine figure in a surround setup. In combination with a controlled amplifier, it can without compromise form the supporting axis of an extremely inexpensive stereo system, with which you will be happy for years despite a manageable investment.

Profile Quadral Signum 90:

  • All-round qualities for long and frequent listeners
  • powerful, warm, voluminous bass, which makes it ideal for large rooms
  • full-bodied, driving and rousing overall tuning, which puts homogeneity before detailed resolution
  • Very fine-resolution and clear tweeter, regardless of price class, which can only be implemented via technology transfer from a large-scale manufacturer
  • Exemplary neutral, pleasant midrange, with slight deficits in the fine resolution
  • Broad stereo panorama with the most free installation possible. In terms of depth graduation rather limited
  • In terms of coarse dynamics, it is very gripping and level stable, in terms of fine dynamics it is generous in favor of the musical flow
  • consistently high quality from the terminals to switch components to the chassis, generally good workmanship with reasonable material quality, and the little trick of the properly painted front makes it look more expensive than it is
  • Can be expanded to create a coherent surround system in conjunction with other models from the Signum series


  • Model: Quadral Signum 90
  • Concept: passive three-way floorstanding loudspeaker with bass reflex
  • Price per pair: 990 euros
  • Dimensions (H / W / D) and weight: 105 / 19.5 / 34.7 cm, 24.10 kg / each
  • Efficiency: 90 dB / W / m
  • Nominal impedance: 4 ohms
  • Connection: single wiring terminal
  • Versions: black or white lacquered baffle, foiled housing
  • Guarantee: 5 years