Center: The center of the gradient, as an offset into the (-1.0, -1.0) x (1.0, 1.0) square describing the gradient which will be mapped onto the paint box. Radius: The radius of the gradient, as a fraction of the shortest side of the paint box. TileMode: How this gradient should tile the plane beyond the outer ring at radius pixels from the. Fracture gradient (FG), also known as frac gradient, is the pressure gradient at which the formation breaks. Frac gradient is crucial to understand in order to calculate the expected bottom-hole treating pressure (BHTP) before the start of a frac job. (9.5) can be used to calculate the frac gradient. Numerical gradients, returned as arrays of the same size as F.The first output FX is always the gradient along the 2nd dimension of F, going across columns.The second output FY is always the gradient along the 1st dimension of F, going across rows.For the third output FZ and the outputs that follow, the Nth output is the gradient along the Nth dimension of F.

In a world dominated by typical loudspeakers, Gradient company stands out. Open baffle designs are both a rarity today and retired CEO Jorma Salmi’s trademark. Yet recently something has changed as latest floorstanding addition to Finnish offer – Gradient 6.0 – looks surprisingly usual. Loaded with a very characteristic coaxial driver and a passive membrane it makes one wonder: what’s really going on in there? 8dio agitato sordino strings.

Introduction

For the first time I witnessed Gradient sound in May 2013. In one of the most beautiful cities in Poland – Wrocław – during a two-day event known as “Audiofil”, Finnish Helsinki 1.5 floorstanders were presented. The outcome was that many visitors were a bit puzzled at first including yours truly, due to large 100 sq. meters room and rather modestly sized product. Though it could be seen that this $6’500 3-way dipole was much more than just an awkward and showy product, far from it. Its 30 cm bass driver is placed not towards the listener but mounted in a plywood made open baffle firing sideways. Remaining drivers sit in their polymer plates and a cardioidal radiation pattern soundwaves are the outcome. Many people would say that Helsinki 1.5 is a visual oddity but from an engineering standpoint it is quite the opposite.Once Finnish floorstanders started their performance, everyone payed full attention. A very wide sweetspot and quite stunning spaciousness were heard instantly. After this experience and some journalistic digging it all became clear. Jorma Salmi is the man behind the Gradient operation placed in a Finnish town of Porvoo. Said gent isn’t new to the speakers game, quite the contrary. One of his main principles from the get go was to make products as much room independent as possible and this hasn’t changed over the years. Quite spectacular soundstage, coherence and peculiar looks are direct upshots of Jorma’s speakers research performed for over more than a half a century. For some time he worked for Nokia as an RF waves engineer and then in Lohja Corporation’s consumer branches; television and loudspeakers. While working for the latter company, he managed an acoustical laboratory, has conducted many experiments and over many years of said operation he possessed an extensive knowledge about exact impact an environment has on sound. Then Jorma founded Gradient Ltd. in 1984 and – needless to say – he started making loudspeakers for home audio.Gradient 1.0 was the very first commercial product Jorma released. After a while he also wanted it to look more modern. Avanti monitor was the outcome of his cooperation with Finnish interior designer Jukka Vaajakallio. Said speaker gained Gradient quite a recognition and was awarded with several prestigious prizes in the process. Visually reworked Gradient 1.0 model simply known as Gradient 1.3 appeared next. It serves as an exhibit in museums of industrial art in Helsinki and Tokyo and was the first one Jorma exported. Another milestone in Gradient’s history was Revolution model introduced in 1994 and after all those years it’s still in production.There are at least several key products in Gradient’s portfolio, namely aforementioned Helsinki 1.5 or Revolution’s smaller sibling known as Evidence. But Jorma gained worldwide attention thanks to a tiny two-way Prelude monitor loaded with a characteristic coaxial driver with yellow membrane. The man behind Combak Corporation’s (Reimyo, Harmonix, Enacom, Encore) – Kazuo Kiuchi – grew very fond of Prelude. Harmonix Bravo! model is the upshot of said gents cooperation and after more than a decade it’s also still in production. A while ago Jorma’s son – Atte – took over Gradient. He also has a technical background, for many years he worked for Finnish Vaisala corporation. It comes as no surprise that Atte inherited many things after his father and the passion for his usual speakers is one of them. Jorma and his son conjoined their efforts and Gradient 6.0 was born in the process. Though in comparison to earlier models it looks unusually normal. But rest assured that in 6.0’s case an apple also doesn’t fall too far away from a tree.

Design

With its 90 x 20,2 x 17,3 cm (H x W x D) dimensions and 12 kg mass, Gradient 6.0 is tiny to say the least whereas its visuals are undoubtedly Finnish, minimalistic. Subjectively, this non-flashy appearance is quite likeable. The enclosure is mostly wooden and finished in satin alike fashion. Birch plywood is used in both front and rear baffle and then covered in rubbery Fenix NTM material of Italian origin. Aesthetics aside it’s also extremely durable; scratch and high temperature proof. On said material’s homepage there is a rather convincing video with kitchen furniture heavily covered with it. Gradient 6.0 is available with white or black fronts and grills whereas third option is a completely white finish yet with MDF used instead of ply. Manufacturer says it has no impact on sound quality. The product is well-made, there’s no real reason to nitpick. Yes, a slight amount of unevenly distributed glue or lacquer is seen in its joints. But for yours truly this is a case of carpentry manufacturing and not sloppiness. That aside, I saw nothing disturbing.On Gradient’s 6.0 front there are only two elements; manufacturer’s aluminum logo and coaxial driver mounted way above it. Latter isn’t any random one but an effect of Jorma’s and Seas cooperation from many years ago. This particular unit is seen in Gradient 5.0, Harmonix Bravo! and Encore ENC-5 and said Finnish constructor dealt with each of these bookshelf models. Characteristic yellow membrane is made out of a fiberglass and has 176 mm diameter whereas 25 mm tweeter is an aluminum one. Seas has been making these drivers for more than 20 years. 6.0 model’s rear isn’t a typical one. Placed above aluminum plate with specs and a pair of a very decent speaker terminals, 140 x 200 mm passive radiator stands out. Even despite lack of typical ventilation, Finnish product is a bass-reflex design whereas said driver is used instead of a vent. According to Jorma, this solution fixes a common problem in most two-way speakers, namely the half-wave resonance in a bass-reflex port. According to Jorma, for instance if this element is 25 cm long, it will resonate at 686Hz. I wasn’t able to get to speakers guts but Atte was helpful in that regard. Polyester wadding is a damping material. Plastic film capacitors and air-cored inductors are used in a passive crossover. Low-pass filtration for bass/midrange is of 2nd order, 3rd order high-pass handles the tweeter. Crossover point for dual concentric driver is set quite high, at 2800 Hz. Speakers nominal impedance is 8 ohms whereas efficiency is an average 86 dB (2.83V/1m). Getting back to terminals, those are great; solid and able to accept any kind of cable termination there is.

Sound

Gradient 6.0 is a very civilized product as its room requirements are minimal to say the least. It was designed to work in small or medium environments, namely from 15 to 35 square meters space. Generous air amount around many speakers is usually beneficial and KEF LS50 is one of many examples. When placed in the middle of the room this product will perform much better than with 30 centimeters of free space or so around it. Finnish speakers are of a completely different kind as in such airy circumstances their bass is nearly completely gone. But things drastically change once distance between their passive membranes and a wall is no smaller than 20 cm and no bigger than twice that. Gradient 6.0 being literally married to said surface is a mandatory condition, there is no other way around it. Unless one isn’t