Koss KSC21
Koss KSC21 Headphones User Manual
Model: KSC21
Introduction
Thank you for choosing Koss KSC21 Headphones. These lightweight, on-ear headphones are designed for comfortable listening with clear audio reproduction. They feature soft foam ear cushions and an open, hear-through sound design, allowing you to enjoy your audio while remaining aware of your surroundings.
- Wide-range frequency response: Delivers clear and balanced audio across various sound frequencies.
- Soft foam ear cushions: Provides comfort for extended listening sessions.
- Open, hear-through sound: Allows ambient sounds to be heard, enhancing situational awareness.

Image: Koss KSC21 Headphones in black, showcasing their wired connection and on-ear design.
Setup
Follow these steps to set up your Koss KSC21 Headphones for use:
- Unpack the Headphones: Carefully remove the headphones and any included cables from the packaging.
- Connect the Audio Cable:
Locate the audio cable attached to your KSC21 headphones. Insert the 3.5mm audio jack into the headphone port of your audio device (e.g., smartphone, tablet, computer, MP3 player).
Video: Demonstrates connecting wired headphones to an audio source. This video shows a person plugging a 3.5mm jack into a computer's headphone port.
- Position the Headphones:
Gently place the headphones over your ears. Adjust the ear clips to ensure a comfortable and secure fit. The soft foam ear cushions should rest comfortably on your ears.

Image: A person wearing clip-on headphones, illustrating how to correctly position them on the ears for comfort and sound.
Video: Illustrates the process of selecting and connecting a compatible audio cable to headphones, showing different cable types (Lightning, USB-C) and how they connect to the headphone's 2.5mm jack.
Operating Instructions
Once connected, your Koss KSC21 Headphones are ready for use. Simply play audio from your connected device.
- Volume Control: Adjust the volume directly from your audio source device. The KSC21 headphones do not feature inline volume controls.
- Comfort: The soft foam ear cushions and lightweight design ensure comfort during prolonged listening.
- Situational Awareness: The open, hear-through design allows you to hear ambient sounds, which is beneficial for safety in certain environments.

Image: Individuals wearing Koss headphones in different environments, demonstrating typical usage.
Maintenance
Proper care will extend the life and performance of your Koss KSC21 Headphones.
- Cleaning Ear Cushions: Gently wipe the foam ear cushions with a soft, damp cloth. Avoid using harsh chemicals or abrasive cleaners. Ensure they are completely dry before use.
- Cable Care: Avoid sharp bends or excessive pulling on the audio cable. Store the headphones in a way that prevents the cable from tangling or being pinched.
- Storage: When not in use, store your headphones in a clean, dry place away from extreme temperatures and direct sunlight.
Troubleshooting
If you encounter issues with your Koss KSC21 Headphones, refer to the following common solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound or low volume |
|
|
| Sound is distorted or crackling |
|
|
| Headphones are uncomfortable |
|
|
Specifications
| Brand | Koss |
| Model Number | KSC21 |
| Colour | Black |
| Form Factor | On-Ear |
| Connectivity Technology | Wired |
| Enclosure Material | Foam |
| Additional Features | Lightweight |
| Noise Control | None (Open, hear-through design) |
| Product Dimensions | 5.59 x 6.99 x 17.78 cm; 40 g |
| Number of Items | 2 units |
| UPC | 021299175545 |
| GTIN | 021299175545 |
Warranty Information
Koss products are manufactured to high-quality standards. For specific warranty details regarding your KSC21 Headphones, please refer to the warranty card included with your purchase or visit the official Koss website. Keep your proof of purchase for warranty claims.
Customer Support
If you require further assistance or have questions not covered in this manual, please contact Koss customer support. Contact information can typically be found on the Koss official website or on the product packaging.
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