WildDetect recommends the BirdAlert ™ speaker. It is prepared for easy installation and has low power consumption, IP66 authentication and the right frequencies. (Monacor 4 iv passive horn speaker (300073). Type: NR-254KS. Frequency range: 600Hz – 14,000Hz, SPL (1W / 1m): 107 dB.). If BirdAlert ™ is to be connected to other speakers, they must be controllable via a 1 amp 12 volt signal and connected with the Weipu SP13 4 pole male connector.