When that for a long time, approximately in 1973, I have heard as can sound shock music instruments
On audio-equipment.
Before already heard, how in usual apartment real shock installation sounds.
And here I listened to the device which could transfer realistic a sound of shock installation - 
It was the radio-gramophone "Estonia-3.
 Just the plate of group "Flowers" of S.Namina c at that time has widely dispersed  
Eyes at colours "Are a song", in it in the beginning the introduction shock is written precisely down,
And as the plate was at many people, I started it on different radio-gramophones, and anywhere I shock 
Plainly also did not hear, yet has not heard this "Estonia-3". 
Quality of a sound has shaken me.

Plased this - http://www.audes.ee

After many years tried to repeat in self-made designs that sounding, dynamics, boxes were different. 
(C the account of awful position with trade in the USSR electronics) 
Dynamics were, for example, 4A28, 2A9, 15GD-12, 6GD-6, 10GD-34, 8GD-1, 30GD-1.
The sound of that record time was close, at times in general is far from a sound of the real shock.

 Have flown by year, the new century has begun...
To grandsons of owners of radio-gramophones 50х-60х years devices, that surrounds them steels are not necessary,
And they (radio-gramophones, in this case) steels publication at auctions, about sale in magazine's
And тп. 
 As consequence - steels as that are accessible dynamics from these radio-gramophones - 6GDR-1
They were established (on two) in radio-gramophones "Estonia-55" "Estonia-2" "Estonia-3".

There was at me an idea - to repeat acoustics from "Estonia-3", but in a new way - standing,
In a stereo a variant.

Given the Acoustic System (AS) maided itself the closed box, with established not to a forward board 
The panel of Acoustic Resistance (PASS).

Structurally maiding so:
In a forward board and, inside behind it in a box, plywood in the thickness 12мм, просверленны
Simultaneously 30 apertures in diameter of 25 mm.
 At manufacturing the forward board and plywood are fastened, drilled свозные apertures 6мм.
Then them divide, will verify on these directing apertures (in plywood and a forward board порозень)
Already the basic holes перъевым a drill on 25 mm.
Further on a plywood part, strongly pulling, paste three layers Х-Б of a fabric, and connect
Plywood and forward board so that the fabric would appear clamped between plywood and a lobby лдоской, 
And отверствия through coincided. 

 All boards - laminated MDF 16 mm, internal рейки - 20 х 20 mm, рейки grills (after assemblage - 
Are pasted to a forward board) - 10 х 10 mm.
All the sizes long in millimetres.

Wires внутренй distributings from two parts - rigid from braided 2 шт PEL (Russian) in diameter 1.8мм,
Flexible - 4 ps in parallel MGSHV (Russian) section 0.75 mm.
Wires in 4 places are strongly fixed by collars.
The flexible part goes on contacts loudspeakers.
The terminal - Visaton ST 77