The function response did not provide any relevant information regarding solutions to issues with low volume on the iPhone 6 speaker.

If you're experiencing low speaker volume on your iPhone 6, here are some general suggestions to troubleshoot the problem:

1. Check Volume Settings: Ensure that the volume is turned up. Use the physical volume buttons on the side of the iPhone to increase the sound.

2. Disable Do Not Disturb: Make sure that Do Not Disturb mode isn’t enabled, as this can sometimes affect sound notifications and volume levels.

3. Inspect the Speaker Ports: Check for any dust or debris in the speaker grills that might be blocking sound. Clean gently with a soft brush or cloth.

4. Test with Different Apps: Sometimes the volume issue is app-specific. Test the speaker using different apps including music, videos, or calls to identify if it's a universal issue.

5. Reset All Settings: If volume issues persist, you might consider resetting all settings. This won’t erase your data but will reset your configurations. Go to Settings > General > Reset > Reset All Settings.

6. Software Update: Ensure that your iPhone is running the latest version of iOS. Sometimes software updates include fixes for audio issues.

7. Headphone Jack: On occasions, debris in the headphone jack can cause the phone to think headphones are connected, reducing speaker volume. Clean it carefully.

If these tips do not resolve the issue, you may want to consider visiting an Apple Store or contacting Apple Support for further assistance.