BV Audio

                          Full-range speaker 9,5`+ dual concetric 2/3`

                            

                                                             

                                     
DIY project

-Audio engineering and speaker design: BIN service -Branko Kasikovic
-Audio measurements and cabinet design: Goran Mihaljut
-Audio cabinet design and production: Veran Stanojevic Ister

- Idea and commitment: - As in Serbia most sound box constructors are preoccupied with making various Hi Fi cabinet designs and switches with already known factory components and variations on the subject, we came up with the idea of creating a drive loudspeaker with the features that we want, thus opting for a unique and manual making a complete sound box.

-Assignment: -Design a broadband speaker exclusively through manual operation, with as many features as possible. For the sake of gaining knowledge and experience, we have opted for the dual concetrik option, in order to make it easier for some to begin with. - Seven magnetic circuits, do everything possible and make sense through manual work, and thus get a unique product of impressive features with the addition of innovations gained through years of experience in the field.

The magnetic circuit is taken from RCF 15` art 315 speakers with vc = 63mm

-The speaker basket is made by its own design with high precision Waterjet cutting of AL profile d = 5mm,

with the finishing of the plastification.

-The whole basket is assembly-foldable with M5 screws, which allows us to fine-tune the depth as needed by the conicity of the membrane itself.

- How to assemble a speaker basket

Although the original idea was to work with a textile bottom centerpiece, and experiment with different hardness and elasticity, we came to the conclusion that such results did not produce satisfactory results, which the audio measurements themselves confirmed.

-We turned technical solutions to the experience of other masters in the field,  and constructed our own design of the lower centrifuge, which justified our expectations by changing the shape and materials.

        

- We directed our further work to the selection of materials for membrane production, from Balza talpa through various papers, types, thicknesses, etc.

-Handmade paper and bleached white mulberry gave us the best results after treatment with Epanol and Acryl-b.

- By running, we achieved better membrane stiffness

-In this project, we use a PP upper centrifuger, a higher softness.

         

- Making a tweeter horn.

-Material dry shaking wood (approx. 150 years), turning on the lathe by the given measuring sizes

Tungsten- Karbid

-We have opted for 2 / 3` Bose, textile calico ferro f. tweeter

- Making a paper whizzer cone

- Running as a way to stiffen paper

-The idea of the project is to maximize the acoustical-mechanical fabrication of the loudspeaker itself and the materials used to minimize the use of the switch, thus eliminating any accompanying problems that it inevitably brings to the end result.

- During the OPUS No. 5 audio-measuring and in the auditory tests we got the desired results of the speaker.

We can now dedicate ourselves to the design, fabrication and design of the cabinet itself.

-After the budget, we decided to construct a horn maze, and started to design an experimental cabinet.

-After further audio measurements and auditory tests, we have come to the final cabinet design.

             

Teh.podaci:

Sensitivity = 94 dB I mpedance = DC 7 Ohm

Nom.impeance = 8 Ohm 30 Hz-20,000Hz Power sin. 30 W

vc=63,5

                                                                 Flux density Tesla  - 1.2                  

 2/3" HF driver 

for amplifiers od 3W do 25W

The weight of the sound box : 40Kg

single speaker weight: Net 5.2 Kg

  Now we can deal with the finalization of the sound box, the ideological-aesthetic values.

- A thoughtful design solution

-Aesthetic changes during production:

-Access to cabinet making cabinet, median 18mm:

-After the carpentry work, the Dumping of the cabinet and its audio-measuring supplementation and optimization came to the attention.

-Here we used two types of Azmophone, pressed 5mm and plain 20mm, with adhesive bitumen board of 3mm in critical resonant locations.

- After sound optimization other sound cabinets can be done indetrically

-Meanwhile, the decision was made to make the terminal connectors by hand made of pure Cu

-The terminal board is made of Polymethyl - Metacrylat. Gold plated 24k. Printed on a UV printer

Or

-After deciding on the name of the sound box model, the terminal board was opened.

-The name is given after the oldest written trace of the ancient Slavs, after the Goddess of the month SERBONI

in the original written font

 We decided on internal wiring: Internal wiring by Solaja Audio

-Terminal received a Full / Pass switch allowing listening to

full range band and -3dB filter option for 400Hz-6KHz band

-LOCKER FOR THE SPEAKER

- FINALLY FINISHING OF THE PREPARATION AND PAINTING OF THE CABINET CAN BE FINALLY APPROVED.

- PROCEDURE OF WORK PROCEDURE:

Isolant IS 211

Substrate 4CR 2500

Liquid polyester gitAuto base PPG deep black

Matte lacquer PPG hard

                

            

              

- The process of gilding details with 24k gold slips, before painting the cabinet

Lacquering the sound box

Antiquoe look with neat design.

-The following is an installation and sound test:

- Mounting the switch

Components and sound source, in a test case

Amplifier: Sholaya Audio - MIRADA
Phono preamp: - Sholaja Audio PH1
MMTurntable: - Technics SL-M1Ortofom 2M red.
Speakers-: SERBONA

-Conclusion:
- After several hours of testing in various genres of music, we came to the conclusion that the whole project exceeded all our expectations.
-As far as we know, the first and so far the only one in Serbia, we embarked on this project of making the loudspeaker itself - right down to the finished product - a sound box, which can be counted among the Hi End sound boxes.
-The characteristic of our work is based on scientific study, experimentation and manual production of unique products, which are made only to order and never identical with the previous model. So each subsequent model will bear the name SERBON with the addition of MK- (order number), and thus have their own special "sound seal" and character.
- The guideline of our further study is complete independence in work, i.e. we will embark on the production of our own quality paper for the manufacture of speaker membranes, which in our opinion can meet our expectations in the next project.
-We hope that this gesture of process description will inspire some other creators to indulge in the production of sound units, in an area where there is very little literature or just a cursory description of details, and thus move the audio boundaries with the sensitive ideas and constructions.

Presentation of Serbona sound box at  Ulica cafe, Belgrade, Serbia

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Next project, variations on a theme, with a Balza wood membrane