[Developing AV Solutions] When choosing an amplifier for a 70 V system, what amplifier output would be the BEST option for a space with 12 speakers…

To determine the best amplifier, first calculate the total power load required by the speakers. This is done by multiplying the number of speakers by their individual power tap setting: 12 speakers × 30 W = 360 W. According to AV system design best practices, an amplifier should have power headroom of at least 20-25% above the total speaker load to prevent clipping and potential damage. Calculating with a 25% headroom: 360 W × 1.25 = 450 W. The 500 W amplifier (Option A) is the only choice that safely exceeds the 450 W requirement, providing adequate power and headroom for optimal performance in a single-channel 70 V configuration. CertEmpire.com

1. AVIXA International. (2020). CTS-D Certified Technology Specialist-Design Exam Guide, Third

Edition. McGraw-Hill. p. 168. "A good rule of thumb is to select an amplifier that has 25 percent

more power than the total tap ratings of all the speakers connected to it."

2. QSC Audio Products, LLC. (2012). Selector Guide: 70V/100V Transformers and Autoformers.

p. 2. "The sum of the power settings of all the speakers on the line must not exceed the

amplifier’s rated continuous power output. It is good practice to leave 20% 'headroom' on the

amplifier..." https://www.qsc.com/resource-files/productresources/amp/discontinued/dataports/leg

acy70v100vxfmrsandautoformersselectorguide.pdf

3. Yamaha Corporation. (n.d.). Commercial Installation Solutions Speaker Guide. p. 10. "The total

of the speaker wattage settings must not exceed the output power of the amplifier. It is

recommended that the total of the speaker wattage settings should be about 80% of the

amplifier’s output power."

https://ca.yamaha.com/files/download/otherassets/1/332251/cisspeakerguide.pdf