News & Media
Tech Talk With Big Tony
Here’s a question I get often: “You recommend a 150 watt speaker for my 40 watt amp? Will my amp have enough power to push it? I have heard that under powering a speaker can do harm.”
Guitar speakers are typically very efficient (high in SPL) and therefore do not require an abundance of power to push them effectively or to make them loud. The SPL on most of our guitar speakers is 98-103dB at 1 watt, 1 meter from a microphone. A 3dB gain can be achieved by doubling the amp power. A 5 watt amplifier, for example, could potentially give you 109+dB of output on a 103dB speaker. Sure, some speakers sound “better” with more power, but adequate sound quality can be achieved at lower volumes as well.
SPL stands for sound pressure level and is also commonly referred to as efficiency and sensitivity. This parameter represents how loud a speaker is. A higher SPL equates to a louder speaker. SPL ratings are very useful and well represent speaker output when comparing one manufacturer’s speaker to another model of the same manufacturer. It can be misleading, however, when comparing two different manufacturer’s ratings.
It is crucial to match your speaker impedance (ohms) with your amplifier’s output impedance. Speaker impedance varies with frequency, so it is possible to approach dangerous conditions for your amplifier with an incorrect impedance load. A lot of amplifiers have multiple taps to accept various cabinet/speaker impedances. On a solid-state amplifier, you gain power by lower speaker impedance. On a tube amplifier, you can safely connect a variety of different cabinets or speaker configurations. Plus, the various taps on a tube amplifier may give you a subtle difference in sonic quality. We recommend that you never connect a different speaker or cabinet impedance than what is listed on your amplifier without checking with the manufacturer to determine if it is safe.