4 GDSh-1-4 (4 GD-43) aka 4 GD-8E

exUSSR low-frequency dynamic drivers

4GD-5

Purpose - use of class 1 transistor receivers (“Riga-102” and “Riga-103”) in acoustic systems. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by stamping steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Hz	63 — 5000
Frequency response unevenness	db	10
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	45+-10
Induction in the working gap	Wb/m2	0.97
dimensions	mm	d202x76
Weight	G	1150

4GD-43E

Purpose - use in acoustic systems of household radio equipment as a low-frequency link when working indoors. The loudspeaker head is electrodynamic type, low-frequency, round. The diffuser holder is made by stamping steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	63 — 5000
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,15
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	6
Fundamental Resonance Frequency	Hz	60+-10
dimensions	mm	d125x54
Weight	G	600

5GD-3 RRZ

Effective operating frequency range	Hz	40 — 5000
Frequency response unevenness	db	12
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	10
Fundamental Resonance Frequency	Hz	30+-5
dimensions	mm	d252x106
Weight	G	1300

6GD-1

Purpose - use in acoustic systems of high-class radio receivers as a low-frequency link. The loudspeaker head is of electrodynamic type, low-frequency, oval, with a semi-shielded magnetic circuit. The diffuser holder is made by stamping steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	60 — 6500
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	2
Fundamental Resonance Frequency	Hz	48+-8
Induction in the working gap	Wb/m2	0,9
dimensions	mm	d222x96
Weight	G	500

6GD-1 RRZ

Purpose - use of high-class radio receivers (“Festival”) in acoustic systems as a low-frequency link. The loudspeaker head is of electrodynamic type, low-frequency, oval, with a semi-shielded magnetic circuit. The diffuser holder is made by stamping steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	60 — 6500
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,4
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	Hz 48+-8
dimensions	mm	327x225x130
Weight	G	1300

6GD-2

Purpose - use of high-class radio receivers (“Symphony”) in acoustic systems as a low-frequency link. The loudspeaker head is of electrodynamic type, low-frequency, oval, with a semi-shielded magnetic circuit. The diffuser holder is made by stamping steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	40 — 1000
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	8
Fundamental Resonance Frequency	Hz	30+-5
Induction in the working gap	Wb/m2	0,95
dimensions	mm	d252x135
Weight	G	1560

8GD-1

Purpose - use in acoustic systems of high-class radiograms as a low-frequency link. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made of stamped steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	40 — 10000
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,2
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	30
Fundamental Resonance Frequency	Hz	25+-5
Induction in the working gap	Wb/m2	0,87
dimensions	mm	d250x152
Weight	G	5700

8GD-1 RRZ

Purpose - use in acoustic systems of high-class radiograms (Victoria) as a low-frequency link. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made of stamped steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	50 — 7000
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,45
Nominal electrical resistance	Ohm	12
Fundamental Resonance Frequency	Hz	55+-15
dimensions	mm	d250x152
Weight	G	5700

10GDN-1-4(6GD-6)

Purpose - use in closed remote acoustic systems of household radio equipment of the 2nd complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The cone diffuser is made of impregnated paper pulp. triad-shaped suspension made of rubber. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	80 — 5000
Characteristic sensitivity level	dB/W*m	84
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,1
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	10
Limiting long-term power	W	12
Maximum short-term power	W	25
Fundamental Resonance Frequency	Hz	80+-8
Equivalent volume, Vas	Liter	11
Total quality factor, Qts	1+-0,5
dimensions	mm	d125x76
Weight	G	1500

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,2
Number of winding layers	2
Number of turns in 1st layer	37
Number of turns in the 2nd layer	36
Coil ohmic resistance	Ohm	3,5+-0,5
Voice coil height	mm	20,5
Inner diameter	mm	25,4
Outer diameter, including winding	mm	26,5

10GD-17

Purpose - use in high-quality acoustic systems of household radio equipment as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic system. The diffuser holder is made of stamped steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	40 — 8000
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	50+-10
dimensions	mm	d259x140
Weight	G	1500

10GD-18

Effective operating frequency range	Hz	50 — 8000
Frequency response unevenness	db	12
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	50+-10
dimensions	mm	324x212x128
Weight	G	2000

10GD-28

Effective operating frequency range	Hz	40 — 6000
Frequency response unevenness	db	12
Average standard sound pressure	Pa	0,3
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	40+-10
dimensions	mm	d295x112
Weight	G	1300

10GD-29

Purpose - use in remote high-quality acoustic systems as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic system. The diffuser holder is made of stamped steel. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	50 — 5000
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,25
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	30+-5
Induction in the working gap	Wb/m2	0,8
dimensions	mm	d300x140
Weight	G	3000

10GD-30E

Purpose - use in closed remote acoustic systems of household radio equipment of the 2nd complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic system. The diffuser holder is made by injection molding from aluminum alloy. The conical diffuser with a curved generatrix is made of impregnated paper pulp. The toroidal suspension is made of rubber. The centering washer is made of impregnated fabric. The cap is spherical in shape with a hole in the center.

Effective operating frequency range	Hz	63 — 5000
Average standard sound pressure	Pa	0,15
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	20
Fundamental Resonance Frequency	Hz	32+-8
dimensions	mm	d240x115
Weight	G	2100

20GDN-1-8 (10GD-30B)

Effective operating frequency range	Hz	63 — 5000
Characteristic sensitivity level	dB/W*m	86
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,15
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	20
Limiting long-term power	W	30
Maximum short-term power	W	45
Fundamental Resonance Frequency	Hz	32+-8
Equivalent volume, Vas	Liter	20
Total quality factor, Qts	1+-0,5
dimensions	mm	d200x97
Weight	G	2100

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,2
Number of winding layers	2
Number of turns in 1st layer	48
Number of turns in the 2nd layer	45
Coil ohmic resistance	Ohm	7+-0,5
Voice coil height	mm	23,8
Inner diameter	mm	40,3
Outer diameter, including winding	mm	41,8

20GDN-2-4(10GD-30B)

Effective operating frequency range	Hz	80 — 3150
Characteristic sensitivity level	dB/W*m	81
Frequency response unevenness	db	18
Total Harmonic Distortion	%	3 — 4
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	20
Limiting long-term power	W	30
Maximum short-term power	W	45
Fundamental Resonance Frequency	Hz	50+-10
dimensions	mm	d125x70.7
Weight	G	1200

Voice coil design

Wire brand	PEVL
Wire diameter	mm	0,224
Number of winding layers	2
Number of turns in 1st layer	44
Number of turns in the 2nd layer	44
Coil ohmic resistance	Ohm	3,6+-0,5
Voice coil height	mm	21
Inner diameter	mm	25,6
Outer diameter, including winding	mm	26,9

25GDN-1-4(10GD-34)

Effective operating frequency range	Hz	63 — 5000
Characteristic sensitivity level	dB/W*m	84
Frequency response unevenness	db	12
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	25
Limiting long-term power	W	27
Maximum short-term power	W	30
Fundamental Resonance Frequency	Hz	80+-20
Equivalent volume, Vas	Liter	11
Total quality factor, Qts	0.45+-0.1
dimensions	mm	d125x75.5
Weight	G	1300

Voice coil design

Wire brand	PEL
Wire diameter	mm	0,23
Number of winding layers	2
Number of turns in 1st layer	46
Number of turns in the 2nd layer	45
Coil ohmic resistance	Ohm	3,1+-0,4
Voice coil height	mm	25,4
Inner diameter	mm	25,4
Outer diameter, including winding	mm	26,6

25GDN-1-8 (25GD-26)

Effective operating frequency range	Hz	40 — 5000
Characteristic sensitivity level	dB/W*m	84
Frequency response unevenness	db	14
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	30
Equivalent volume, Vas	Liter	30
Mechanical quality factor, Qms	4,72
Electrical quality factor, Qes	0,375
Total quality factor, Qts	0,35
dimensions	mm	d200x97
Weight	G	2100

25GDN-2-4 (15GD-18)

Effective operating frequency range	Hz	80 — 3150
Characteristic sensitivity level	dB/W*m	81
Frequency response unevenness	db	14
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	63
dimensions	mm	d125x75.5

25GDN-3-4 (15GD-14)

Purpose - use in closed remote acoustic systems of household electronic equipment of the 1st and 2nd complexity groups as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The diffuser is made of impregnated paper pulp. The suspension is toroidal in shape, made of rubber, and is glued to the outer edge of the diffuser. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	50 — 5000
Characteristic sensitivity level	dB/W*m	84
Frequency response unevenness	db	14
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	25
Limiting long-term power	W	30
Maximum short-term power	W	70
Fundamental Resonance Frequency	Hz	55+-10
Equivalent volume, Vas	Liter	8
Total quality factor, Qts	0,5+-0,5
dimensions	mm	d125x79
Weight	G	2000

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,224
Number of winding layers	2
Number of turns in 1st layer	47
Number of turns in the 2nd layer	46
Coil ohmic resistance	Ohm	3,1+-0,4
Voice coil height	mm	22,5
Inner diameter	mm	25,4
Outer diameter, including winding	mm	26,6

25GDN-3-8

Purpose - use in closed remote acoustic systems of household radio equipment of the 1st and 2nd complexity groups as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The diffuser is made of impregnated paper pulp. The suspension is toroidal in shape, made of rubber, and is glued to the outer edge of the diffuser. The centering washer is made of impregnated fabric. The cap is spherical.

Effective operating frequency range	Hz	40 — 5000
Characteristic sensitivity level	dB/W*m	86
Frequency response unevenness	db	12
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	25
Limiting long-term power	W	30
Maximum short-term power	W	70
Fundamental Resonance Frequency	Hz	40+-10
Equivalent volume, Vas	Liter	30
Mechanical quality factor, Qms
Electrical quality factor, Qes
Total quality factor, Qts	0,35+-0,5
dimensions	mm	d160x78
Weight	G	1400

Voice coil design

Wire brand	PEVT-1
Wire diameter	mm	0,224
Number of winding layers	2
Number of turns in 1st layer	61
Number of turns in the 2nd layer	56
Coil ohmic resistance	Ohm	6,7+-0,4
Voice coil height	mm	22,5
Inner diameter	mm	25,4
Outer diameter, including winding	mm	26,6

25GDN-4-4 (15GD-17)

Effective operating frequency range	Hz	40 — 5000
Characteristic sensitivity level	dB/W*m	88
Frequency response unevenness	db	14
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	40
dimensions	mm	d160x78
Weight	G	1400

30GD-1

Purpose - use in closed remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	30 — 1000
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,15
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	70
Fundamental Resonance Frequency	Hz	25+-5
dimensions	mm	d250x125
Weight	G	6000

35GDN-1-4 (25GD-26B)

Purpose - use in closed remote acoustic systems of household radio equipment of the highest and 1st complexity groups as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The cone diffuser is made of impregnated paper pulp. The suspension is toroidal-shaped and made of rubber. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	40 — 5000
Characteristic sensitivity level	dB/W*m	84
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,12
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	35
Limiting long-term power	W	50
Maximum short-term power	W	125
Fundamental Resonance Frequency	Hz	30+-5
Equivalent volume, Vas	Liter	50
Total quality factor, Qts	1+-0,5
dimensions	mm	d200x97
Weight	G	2100

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,28
Number of winding layers	2
Number of turns in 1st layer	47
Number of turns in the 2nd layer	44
Coil ohmic resistance	Ohm	3,6+-0,36
Voice coil height	mm	26,2
Inner diameter	mm	40,32
Outer diameter, including winding	mm	42,0

35GDN-1-8 (25GD-26B)

Effective operating frequency range	Hz	40 — 5000
Characteristic sensitivity level	dB/W*m	87
Frequency response unevenness	db	14
Average standard sound pressure	Pa	0,12
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	35
Limiting long-term power	W	50
Maximum short-term power	W	125
Fundamental Resonance Frequency	Hz	30+-5
Equivalent volume, Vas	Liter	45
Mechanical quality factor, Qms	5,8
Electrical quality factor, Qes	0,44
Total quality factor, Qts	0,4
dimensions	mm	d200x126
Weight	G	2400

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,224
Number of winding layers	2
Number of turns in 1st layer	60
Number of turns in the 2nd layer	57
Coil ohmic resistance	Ohm	6.8+-0.5
Voice coil height	mm	26,2
Inner diameter	mm	40,32
Outer diameter, including winding	mm	42

50GD-25 (15GD-11)

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The diffuser is made of impregnated paper pulp. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	30 — 1000
Characteristic sensitivity level	dB/W*m	90
Frequency response unevenness	db	15
Average standard sound pressure	Pa	0,2
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	95
Fundamental Resonance Frequency	Hz	25+-5
dimensions	mm	d315x170
Weight	G	4300

50GDN-1-8 (35GD-1)

Effective operating frequency range	Hz	31,5 — 4000
Characteristic sensitivity level	dB/W*m	85
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	50
Fundamental Resonance Frequency	Hz	25
dimensions	mm	200x200x100

50GDN-3-4

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest and 1st complexity groups as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The conical diffuser of variable thickness is made of impregnated paper pulp. The suspension is toroidal in shape and made of polyurethane. The centering washer is made of impregnated fabric. The cap is spherical in shape.

Effective operating frequency range	Hz	31,5 — 2000
Characteristic sensitivity level	dB/W*m	87
Frequency response unevenness	db	12
Nominal average sound pressure	Pa	1,26
Total Harmonic Distortion	%	3 — 5
Nominal electrical resistance	Ohm	6
Maximum noise (nameplate) power	W	50
Limiting long-term power	W	65
Maximum short-term power	W	100
Fundamental Resonance Frequency	Hz	30+-3
Equivalent volume, Vas	Liter	100
Total quality factor, Qts	0,45+-0,25
dimensions	mm	d250x120.3
Weight	G	4750

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,35
Number of winding layers	2
Number of turns in 1st layer	55
Number of turns in the 2nd layer	43
Coil ohmic resistance	Ohm	3,4+0,2-0,3
Voice coil height	mm	33,5
Inner diameter	mm	50,7
Outer diameter, including winding	mm	52,45

50GDN-3-8 (25GD-4)

Effective operating frequency range	Hz	31,5 — 2000
Characteristic sensitivity level	dB/W*m	85
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	25
dimensions	mm	d250x120

75GDN-1-4 (30GD-2)

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The cone diffuser is made of impregnated paper pulp. The suspension is toroidal-shaped and made of rubber. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	31,5 — 1000
Characteristic sensitivity level	dB/W*m	86
Frequency response unevenness	db	10
Nominal average sound pressure	Pa	1,26
Nominal electrical resistance	Ohm	6
Maximum noise (nameplate) power	W	50
Limiting long-term power	W	65
Maximum short-term power	W	100
Fundamental Resonance Frequency	Hz	30+-3
Equivalent volume, Vas	Liter	80
Mechanical quality factor, Qms	3,25
Electrical quality factor, Qes	0,225
Total quality factor, Qts	0,21
dimensions	mm	d250x123
Weight	G	4750

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,35
Number of winding layers	2
Number of turns in 1st layer	55
Number of turns in the 2nd layer	43
Coil ohmic resistance	Ohm	3,4+0,2-0,3
Voice coil height	mm	33,5
Inner diameter	mm	50,7
Outer diameter, including winding	mm	52,45

75GDN-1-8

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The cone diffuser is made of impregnated paper pulp. The suspension is toroidal-shaped and made of rubber. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	31,5 — 1000
Characteristic sensitivity level	dB/W*m	86
Frequency response unevenness	db	10
Nominal average sound pressure	Pa	1,26
Total Harmonic Distortion	%	3
Nominal electrical resistance	Ohm	8
Maximum noise (nameplate) power	W	75
Limiting long-term power	W	78
Maximum short-term power	W	80
Fundamental Resonance Frequency	Hz	25+-5
Equivalent volume, Vas	Liter	80
Mechanical quality factor, Qms	6,17
Electrical quality factor, Qes	1
Total quality factor, Qts	0,88
dimensions	mm	d250x124
Weight	G	6000

Voice coil design

Wire brand	PEVTL-1
Wire diameter	mm	0,28
Number of winding layers	2
Number of turns in 1st layer	67
Number of turns in the 2nd layer	69
Coil ohmic resistance	Ohm	6,7+-0,3
Voice coil height	mm	41,6
Inner diameter	mm	50,7
Outer diameter, including winding	mm	52,6

75GDN-2-8 (35GD-2)

Effective operating frequency range	Hz	31,5 — 5000
Characteristic sensitivity level	dB/W*m	87
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	30
dimensions	mm	d250x120

75GDN-3-4

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from aluminum alloy. The diffuser is a conical shape of variable thickness and the cap is made of impregnated paper pulp. The suspension is toroidal in shape and made of polyurethane. The centering washer is made of impregnated fabric.

Effective operating frequency range	Hz	31,5 — 2000
Characteristic sensitivity level	dB/W*m	86
Frequency response unevenness	db	12
Average standard sound pressure	Pa	0,15
Nominal average sound pressure	Pa	1,26
Total Harmonic Distortion	%	3 — 6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	75
Limiting long-term power	W	78
Maximum short-term power	W	100
Fundamental Resonance Frequency	Hz	25+-5
Equivalent volume, Vas	Liter	100
Total quality factor, Qts	0,25+-0,05
dimensions	mm	d250x120
Weight	G	4900

Voice coil design

Wire brand	PETV-1
Wire diameter	mm	0,355
Number of winding layers	2
Number of turns in 1st layer	53
Number of turns in the 2nd layer	51
Coil ohmic resistance	Ohm	2,9+-0,3
Voice coil height	mm	40
Inner diameter	mm	50,7
Outer diameter, including winding	mm	52,7

75GDN-5-4

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. The loudspeaker head is of electrodynamic type, low-frequency, round, with an unshielded magnetic circuit. The diffuser holder is made by injection molding from an aluminum alloy. A conical diffuser with a curvilinear generatrix of variable thickness is made of impregnated paper pulp. The suspension is toroidal-shaped and made of rubber. The centering washer is made of impregnated fabric. The cap is spherical in shape.

Effective operating frequency range	Hz	31,5 — 1000
Characteristic sensitivity level	dB/W*m	85
Frequency response unevenness	db	12
Total Harmonic Distortion	%	6
Nominal electrical resistance	Ohm	4
Maximum noise (nameplate) power	W	75
Limiting long-term power	W	200
Maximum short-term power	W	300
Fundamental Resonance Frequency	Hz	25+-5
Total quality factor, Qts	0,4+-0,1
dimensions	mm	d250x125
Weight	G	4900

Voice coil design

Wire brand	PETV-2
Wire diameter	mm	0,355
Number of winding layers	2
Number of turns in 1st layer	53
Number of turns in the 2nd layer	51
Coil ohmic resistance	Ohm	2,9+-0,3
Voice coil height	mm	41,6
Inner diameter	mm	50,7
Outer diameter, including winding	mm	52,58

75GDN-6-4 (30GD-6)

Effective operating frequency range	Hz	31,5 — 1000
Characteristic sensitivity level	dB/W*m	88
Nominal electrical resistance	Ohm	4
Fundamental Resonance Frequency	Hz	33
dimensions	mm	d250x124

100GDN-3-8 (75GD-1)

Effective operating frequency range	Hz	31,5 — 1000
Characteristic sensitivity level	dB/W*m	90
Nominal electrical resistance	Ohm	8
Fundamental Resonance Frequency	Hz	32
dimensions	mm	d320x175