|For the freedom of listening

Listening to sounds in a well-crafted listening room is a very exciting experience, but on the other hand you want to enjoy high quality music in the usual places like living room, work room and bedroom. D190 is a compact bookshelf type HI-FI speaker that was born to realize this kind of acoustic space creation. The unique styling that combines a wooden and spherical enclosure with a cylindrical stand has an appeal that traditional box speakers do not have. The size of the ball section of the D190 is 190 mm in diameter, easy to carry and easy to store on a bookshelf. Even if you put the stand height of 275 mm, fits in the A4 document size. You can place it on a bookshelf, TV board, kitchen counter or directly on the floor ... to provide the best acoustic space where you want to listen.

|Simple and beautiful "Acoustic furniture" : High sound quality, wooden sphere Hi-Fi speaker

D190 is compact with high-quality bookshelf speaker. Iconic form combining simple spheres and cylinders, beautiful design taking advantage of the contrast of the material of natural solid oil finish wood and inorganic rubber, as a variety of "acoustic furniture" from living room and bedroom to office It shines in space.

|Spherical is the ideal acoustic enclosure

D190 is not only styling, we are also pursuing high-quality sound. I aimed for a natural, clear sound with a well-balanced mid-high range and low range. Its greatest feature is that it is "spherical". Spherical speakers are said to have a clean sound, but what are the specific features?

The 1951 Acoustical Engineering Research (AES) is a comparative study of speaker enclosure geometry and frequency response (Direct Radiator Loudspeaker Enclosures, Olson, Harry F. November 1, 1951). According to this, spherical enclosures have the result that the level difference of the playback sound pressure for each frequency is smaller than that of the box type. As a factor of this level difference, the influence of the "diffraction phenomenon" by the enclosure shape is pointed out.

- Suppression of diffraction by spherical shape

In a box type speaker, the "diffraction phenomenon" that the sound wave from a unit turns around occurs in a speaker attachment baffle and the corner of a side. Due to this phenomenon, the sound that has come around (second-order diffraction waves) interferes with the direct sound of the original unit, causing a level difference in the reproduced sound pressure. On the other hand, with the spherical D190, since the corners are virtually absent, the effects of the second-order diffracted waves can be almost ignored, making it possible to hear the unit's original sound.

- Free setting by cylinder stand

D190's speaker body and stand are not fixed, allowing for optimal settings according to the listening space at any of the upper, lower, left and right angles. This is something that can not easily be done with box-type speakers.

This structural idea was originally created when the speaker under development was placed on a cylindrical pen stand to prevent it from rolling. The simple structure eliminates the need to add extra parts and structure for mounting the stand on the speaker body, which is also advantageous in sound quality. And by making the material made of urethane rubber that plays the role of insulator, it plays a role in improving the sound quality.

|About acoustic design

At D190, the following acoustic design is performed taking advantage of the advantages of the spherical enclosure.

- Equipped with a high-performance full-range unit

D190 aims to be a Hi-Fi quality that audiophiles can understand. Because of the characteristics of the enclosure in spherical speakers, the unit itself is also required to have high performance. As a result of testing several units, the SP unit adopted Markaudio Alpair 6M full-range unit (9 cm), which features delicate reproduction ability and flat response. It is a high-performance driver with a very unique design that uses aluminum magnesium cone.

- Proprietary structure enclosure

By combining a high-quality unit and a bass-reflex type enclosure with a unique structure using natural wood, it is possible to achieve excellent sound image localization unique to the D190 and achieve high-resolution sound source reproduction.

Instead of making a sound in a box, it delivers the sound of a high-quality unit to the listener's ear as it is, forgetting the existence of an enclosure while listening ... This is also the point stuck in the D190 development.

- Reduction of internal standing waves by optimizing the internal structure of the sphere

In a room composed of parallel planes, "standing waves" that affect the sound quality occur depending on the ceiling height, the width of the room, and the depth. This phenomenon occurs in the same way inside a box-type speaker enclosure and affects the sound quality of the SP unit. In addition to the spherical shape inside the D190, there is no parallel surface because it is composed of a sawtooth-like step. This unique inner wall shape reduces the occurrence of "standing waves".

- Dispersion of resonant frequency by spherical shape / wood material

The rigidity of the spherical enclosure is almost uniform compared to the box type with different rigidity in the corner and body etc., so it is also a major feature that resonance at a specific frequency and "box noise" are less likely to occur. In addition, the structure itself that combines 24 pieces of different wood plays an important role in the dispersion of resonance frequency.


|Audition (Trial Listening) Clips

♪ Strutting It - Joe Robinson - Time Jumpin'

♪ So What, Miles Davis - Kind Of Blue

♪Butterfly, Jeanette Lindstrom, Steve Dobrogosz - Feathers

♪First Time Love, Livingston Taylor - Ink

♪Family Affair, Sly & Family Stone - The Essential Sly & Family Stone, Disc2

♪Hotel California, The Eagles - Hotel California

♪How About You, Bill Evans - Some Other Time: The Lost Session From the Black Forest

♪Get Lucky, Daft Punk Feat. Pharrell Williams - Random Access Memories

♪Rydeen, Yellow Magic Orchestra - Solid State Survivor

♪Rosanna, TOTO - TOTO IV -PaperJacket-2014 CultureFactory

♪Someone To Watch Over Me, Susannah McCorkle - Best Audiophile Voices II

Hi-Fi Loudspeaker D190 Specification

  • Type: Bass reflex, full range
  • SP Unit:9cm Aluminum-magnesium dynamic corn(Markaudio Alpair 6M )
  • Sound pressure level:85.4dB(SP unit)
  • Frequency response: measurement after the trial mass production
  • Input impedance: 4Ω
  • Allowable input: 15W (rated) / 30W (maximum)
  • Dimensions: W190 x H275 x D193 [mm] (including the stand) / W190 x H190 x D193 [mm] (sphere part only)
  • Weight: 2.0kg

* The above is the specification of one channel.

* This speaker has no built-in amplifier. In order to enjoy the music, amplifier and speaker cable Please also available.

* For the specifications and design are subject to change part.

System configuration example

D190 is a 2ch stereo speakers of the left and right two-1 pair.

There is no amplifier built into this speaker. In order to enjoy the music, amplifier and speaker cable Please also available.

These days, very compact, affordable, high-performance digital power amplifiers are being marketed. Please have this in a try to sound the all means D190. You can hear the sound you couldn't hear with the portable speakers you've been listening to before.


D190 is the first of the original product of kitamura_design. Various inquiries about the products, please fill out this form.

©2021 kitamura_design
Using Format