JBL 308P MkII 8-inch Studio Monitoring Speakers User Manual

1. Introduction and Overview

The JBL 308P MkII is an 8-inch powered studio monitor designed for professional audio applications. This manual provides essential information for the proper setup, operation, and maintenance of your speakers to ensure optimal performance.

Key features of the JBL 308P MkII include:

• Next-generation JBL transducers for superior transient response and deep bass with lower harmonic distortion.
• New Boundary EQ to restore neutral low-frequency response when speakers are placed near walls or on a work surface.
• Sleek, modern design suitable for any studio environment.
• Broad sweet spot for neutral frequency response across a wide listening area, allowing for accurate mixing even off-axis.

Image 1.1: A pair of JBL 308P MkII 8-inch Studio Monitoring Speakers, showcasing their front design with the JBL logo and drivers.

2. Unpacking

Carefully unpack your JBL 308P MkII speakers by following these steps:

1. Remove the outer shipping carton.
2. Place the inner carton on the floor with the top face upwards.
3. Open the top of the box.
4. Without removing the internal packaging, turn the carton over so the open end rests on the floor and the bottom of the carton faces you.
5. Gently lift the carton, allowing the speaker and protective end-cap to slide out of the carton and remain on the floor.

Image 2.1: The retail packaging box for the JBL 308P MkII speaker.

Image 2.2: A section of the Quick Setup Guide illustrating the recommended unpacking procedure for the JBL 3 Series MkII speakers.

3. Setup

3.1 Placement

Proper speaker placement is crucial for accurate monitoring. Follow these guidelines:

1. Attach the four supplied pads to the bottom of each speaker to protect the finish of the surface.
2. Position each speaker in a vertical orientation with the tweeter on the top.
3. Angle the speakers so the high-frequency drivers of each speaker are aimed directly towards your ear.
4. The speakers should be placed so the listening position and the two speakers form an equilateral triangle. Adjusting the distance between the speakers will affect the quality of bass heard at the listening position. Experiment with different positions to find the placement that produces the preferred bass response and stereo image.

Image 3.1: A diagram from the Quick Setup Guide illustrating optimal speaker placement for an equilateral triangle listening setup.

3.2 Audio Connections

The JBL 308P MkII offers balanced XLR and 1/4-inch TRS inputs. Use the appropriate cable for your audio source.

1. Connect professional equipment with balanced outputs to the XLR or 1/4-inch TRS input of the speaker using balanced cables. Connect consumer equipment with unbalanced outputs to the 1/4-inch TRS input of the speaker using unbalanced signal cables.
2. Set the INPUT SENSITIVITY switch to the +4 dBu setting for most applications. Set the switch to the -10 dBV setting if the content is distorted or if you find it is too loud.
3. When connecting 3 Series MkII speakers to professional equipment with a +4 dBu nominal output level, to determine the nominal output level of the connected equipment, consult the documentation supplied with the connected equipment.

Image 3.2: The rear panel of the JBL 308P MkII speaker, detailing the balanced XLR and 1/4-inch TRS input jacks, along with the INPUT SENSITIVITY switch.

Image 3.3: A section of the Quick Setup Guide illustrating balanced XLR and 1/4-inch TRS audio connection types.

3.3 Power Connections

Connect the speakers to a suitable power source.

1. Confirm the power switch is in the OFF position.
2. Connect the supplied power cord to the power receptacle on the rear of the speaker.
3. Connect the power cord to an available power outlet.

Note:

JBL 3 Series MkII speakers incorporate a universal power supply allowing them to be used worldwide. The ground terminal of the IEC plug on the AC input is for safety grounding and must always be connected to an electrical installation safety ground.

4. Operating

Once the speakers are properly set up and connected, you can begin operation.

1. After connections are made, reduce the output level of the audio source (Mixing Console, Computer Recording System, or Preamplifier) to minimum.
2. Set the 3 Series MkII Power Switch to the "ON" position. After a delay of 7 seconds, when the POWER INDICATOR on the front of each speaker illuminates, the speakers are ready to reproduce audio signals.
3. Driver power and audio source gain. Slowly adjust the volume control of connected audio equipment to achieve a suitable listening level.

4.1 Rear Panel Controls

The rear panel of the 308P MkII features several controls for fine-tuning the speaker's response to your environment:

• BOUNDARY EQ: This switch adjusts the low-frequency response to compensate for acoustic issues caused by speaker placement near walls or on a desktop.
• HF TRIM: This switch allows you to adjust the high-frequency output to match your room acoustics or personal preference.
• VOLUME: Controls the overall output level of the speaker.

Image 4.1: A detailed view of the JBL 308P MkII rear panel, highlighting the BOUNDARY EQ, HF TRIM, and VOLUME controls.

5. Maintenance

To ensure the longevity and optimal performance of your JBL 308P MkII speakers, follow these maintenance guidelines:

• Cleaning: Use a soft, dry cloth to clean the exterior surfaces of the speakers. Avoid using abrasive cleaners, solvents, or waxes, as these can damage the finish.
• Dust Protection: Keep the speakers free from dust. If not in use for extended periods, consider covering them with a dust cover.
• Ventilation: Ensure that the rear panel and any ventilation ports are not obstructed to allow for proper heat dissipation.
• Environmental Conditions: Avoid exposing the speakers to extreme temperatures, high humidity, or direct sunlight.

6. Troubleshooting

If you encounter issues with your JBL 308P MkII speakers, refer to the following common troubleshooting steps:

• No Sound:
  • Check if the power switch is ON and the power indicator is illuminated.
  • Verify all audio cables are securely connected to both the speaker and the audio source.
  • Ensure the volume control on the speaker and the audio source is not set to minimum.
  • Confirm the correct input sensitivity (+4 dBu or -10 dBV) is selected on the rear panel.
• Distorted Sound:
  • Reduce the volume level on both the speaker and the audio source.
  • Check for damaged cables or loose connections.
  • Ensure the audio source output is not clipping or overdriving the speaker input.
• Hum or Buzz:
  • Ensure all equipment is properly grounded.
  • Try connecting the speaker to a different power outlet.
  • Use balanced cables (XLR or TRS) if possible, as they are less susceptible to interference.
  • Move power cables away from audio signal cables.

If the issue persists after following these steps, please contact JBL customer support for further assistance.

7. Specifications

Detailed technical specifications for the JBL 308P MkII 8-inch Studio Monitoring Speakers:

8. Warranty and Support

JBL products are designed for reliability and performance. For information regarding warranty coverage, please refer to the warranty card included with your product or visit the official JBL website.

For technical support, service, or additional product information, please visit the JBL Support website or contact your local JBL dealer.