Kenwood 103SW/SW-301 & 1050SW/SW-501 Powered Subwoofer Service Manual
Service Manual
Specifications
The following table details the specifications for the Kenwood 103SW/SW-301 and 1050SW/SW-501 powered subwoofers. Specifications are subject to change without notice.
| Feature | 1050SW(SW-501) | 103SW(SW-301) |
|---|---|---|
| Power output | 150 watts RMS into 4 ohms, from 20 Hz to 200 Hz, with no more than 0.09% total harmonic distortion | 100 watts RMS into 4 ohms, from 20 Hz to 200 Hz, with no more than 0.09% total harmonic distortion |
| Phase switching | Normal, Reverse | Normal, Reverse |
| Input sensitivity and input impedance | 70 mV (12 k-ohms) | 70 mV (12 k-ohms) |
| RCA-type jack | 1.7 V (15 k-ohms) | 1.7 V (15 k-ohms) |
| Push-type terminals | AC 110 V~120 V (1050SW) | AC 110 V~120 V (103SW) |
| Supply voltage | 150 watts | 110 watts |
| Rated power consumption | Ported | Ported |
| Speaker Enclosure | 12 in (300 mm) polypropylene cone | 10 in (250 mm) polypropylene cone |
| Speaker units | 4 ohms | 4 ohms |
| Nominal impedance | 14.3 in (363 mm) | 11.8 in (300 mm) |
| Width | 21.7 in (550 mm) | 18.9 in (480 mm) |
| Height | 18.9 in (480 mm) with grille | 15.6 in (395 mm) |
| Depth | 53 lb (24 kg) | 40 lb (18 kg) |
| Net weight |
Disassembly for Repair
How to remove the front panel
- Remove the decoration plate (labeled '1') using tweezers, positioning it towards the bottom of the front panel. Then, remove the 3 screws (labeled '2').
- For the 103SW/SW-301: Remove the front panel by pulling it upwards and away from the unit, following the direction indicated by an arrow (labeled '3').
- For the 1050SW/SW-501: Remove the front panel by pulling it straight forward.
Adjustment
Idle Current Adjustment
Unless otherwise specified, individual switches should be set as follows: POWER: ON.
| No. | ITEM | INPUT SETTINGS | OUTPUT SETTINGS | AMPLIFIER SETTINGS | ALIGNMENT POINTS | ALIGN FOR FIG. |
|---|---|---|---|---|---|---|
| 1 | IDLE CURRENT | NO SIGNAL INPUT | Connect a DC voltmeter to R611 | VOLUME: 0 | VR601 | 5 mV (a) |
Diagram (a) shows a DC voltmeter connected to R611, with the alignment point set to 5 mV.
Component Layouts and Diagrams
PC Board (Component Side View)
This section displays a view of the Printed Circuit Board (PCB) from the component side. It illustrates the placement and orientation of various electronic components. For detailed information on component values, refer to the schematic diagram.
Schematic Diagram
The schematic diagram provides a detailed electrical blueprint of the subwoofer's circuitry. It outlines the interconnections between integrated circuits (ICs), transistors, resistors, capacitors, and other electronic components. A table detailing component values and variations based on destination country is also included.
Exploded View (Unit)
The exploded view diagram visually breaks down the subwoofer into its constituent parts, showing how they are assembled. It identifies major components such as the speaker driver, enclosure, front panel, circuit boards, and various hardware like screws and knobs, referencing them with numerical labels for identification in the parts list.
Parts List
The following sections contain detailed parts lists for the Kenwood 103SW/SW-301 and 1050SW/SW-501 powered subwoofers. Parts with exploded numbers larger than 700 are not supplied. A "✽" symbol indicates safety-critical components. Component and circuit modifications may occur to ensure optimal performance under different operating conditions.
103SW/SW-301 Parts List (KP type only)
This list includes reference numbers, part descriptions, part numbers, and destination codes for various components, including screws, trim pieces, panels, knobs, transformers, fuses, and manuals.
1050SW/SW-501 Parts List (KP type only)
This list provides similar details for the 1050SW/SW-501 model, covering components such as screws, panels, knobs, transformers, fuses, and manuals.
Electric Parts
This section details specific electronic components such as LEDs, lamps, capacitors (ceramic, mylar, electrolytic), and fuses, along with their specifications (e.g., capacitance, voltage rating, type) and part numbers.
Transistors, Diodes, ICs, and Other Components
This comprehensive list includes various semiconductors like transistors (e.g., 2SC1815GR, 2SA1015GR, 2SC3281), diodes (e.g., 1SS133, 1SR139-100, D3SBA20), integrated circuits (e.g., NJM4558L, uPD75004CU-076, UPC1298V), voltage regulators, Zener diodes, potentiometers, switches, relays, and fuses, along with their respective part numbers and descriptions.
The manual also provides contact information for Kenwood Service Corporation in Japan and Kenwood Corporation in the USA.
