Poor / weak sound from wired doorbell / wired door chime

There might be insufficient power or too much bell wire has been used. Please check the points below:

• If using battery power then check the batteries are strong, good quality Alkaline or Lithium type batteries. Don't use Zinc type or rechargeable batteries.
• If using transformer power then check the transformer output is a minimum of 8 volt 1 amp. You can use a maximum of 12 volts. 
• Check the cable length from doorbell to bell push and back is under 20 meters.