Reply to thread

Message

<blockquote data-quote="DejaWiz" data-source="post: 3311022" data-attributes="member: 569941">Most amps (not all, as there are some exceptions), output less power at 4 ohms then 2 ohms.Per Ohm&#039;s law, higher resistance results in less power, since the power supply in an amplifier can only draw so much current from the vehicle&#039;s electrical system and is subject to inefficiencies (only a 50% increase in power with a 2 ohm load versus a 4 ohm load).However, when you bridge a pair of channels with a 4 ohms load, the amplifier will output more power than it will at 4 channels with 4 ohms because the output voltage has increased to what it would be at 4 channels with 2 ohms.100W at 4 Ohms:SQRT(Watts*Ohms) = Output Voltage...SQRT(100*4) = 20 Volts per channelVolts / Ohms = AMPS...20 / 4 = 5A per channel (4 channels = 20A total) 150W at 2 Ohms:SQRT(Watts*Ohms) = Output Voltage...SQRT(150*2) = 17.32 Volts per channelVolts / Ohms = AMPS...17.32 / 2 = 8.66A per channel (4 channels = 34.64A total)300W at 4 ohms, Bridged:Output Voltage = SQRT(Watts*Ohms)...SQRT(300*4) = 34.64 Volts per channelVolts / Ohms = AMPS...34.64 / 4 = 8.66A per channel (2 channels = 17.32A total)See the similarity in Amperage between four channels at 2 ohms and two channels at 4 ohms bridged?&nbsp; Also note that the voltage is exactly double when the channels are bridged with a 4 ohm load present then with 2 ohms and 4 channels.</blockquote>

[QUOTE="DejaWiz, post: 3311022, member: 569941"] Most amps (not all, as there are some exceptions), output less power at 4 ohms then 2 ohms. Per Ohm's law, higher resistance results in less power, since the power supply in an amplifier can only draw so much current from the vehicle's electrical system and is subject to inefficiencies (only a 50% increase in power with a 2 ohm load versus a 4 ohm load). However, when you bridge a pair of channels with a 4 ohms load, the amplifier will output more power than it will at 4 channels with 4 ohms because the output voltage has increased to what it would be at 4 channels with 2 ohms. [B]100W at 4 Ohms:[/B] SQRT(Watts*Ohms) = Output Voltage ...SQRT(100*4) = 20 Volts per channel Volts / Ohms = AMPS ...20 / 4 = 5A per channel (4 channels = 20A total) [B] 150W at 2 Ohms:[/B] SQRT(Watts*Ohms) = Output Voltage ...SQRT(150*2) = 17.32 Volts per channel Volts / Ohms = AMPS ...17.32 / 2 = 8.66A per channel (4 channels = 34.64A total) [B]300W at 4 ohms, Bridged:[/B] Output Voltage = SQRT(Watts*Ohms)...SQRT(300*4) = 34.64 Volts per channel Volts / Ohms = AMPS ...34.64 / 4 = 8.66A per channel (2 channels = 17.32A total) See the similarity in Amperage between four channels at 2 ohms and two channels at 4 ohms bridged? Also note that the voltage is exactly double when the channels are bridged with a 4 ohm load present then with 2 ohms and 4 channels. [/QUOTE]

Verification