Bass Guitar Lessons Online

Ohms and Watts Explained - Part 1

(This article is taken from talkbass.com)

 

Impedance

Impedance is a measure of resistance. When electricity flows to a load some of the electricity is resisted, or impeded. Impedance is measured in ohms (denoted with the Greek letter omega — Ω). Most bass cabinets have an impedance of 4 ohms or 8 ohms.
More ohms (higher number) means more resistance. The more resistance there is, the less power will flow to the speaker.

Bass amp heads specify how much power is sent to a load (a cabinet or group of cabinets) of a certain impedance (the amount of resistance measured in ohms). For example, you may see an amp rated “400 Watts @ 4 ohms”.

Let’s look at an example so you better understand all of this. A particular amp head might send 200 Watts into an 8-ohm load. That same amp might send 350 Watts into 4 ohms. More power will flow from an amp as the ohm rating (resistance) decreases. If you went down to 2 ohms, that same amp might send 600 Watts to the load.

All of this is important because amps are designed to work with a certain resistance in mind. If there is not enough resistance, the amp will put out more juice than the amp can handle, and it will overheat and burn up! You don’t want your precious bass amp catching fire no matter how cool it looks on stage.

Hooking Up a Single Bass Cabinet

If you are running your bass head to one cabinet, it’s pretty straightforward. If your bass head says 300 Watts @ 4 ohms, you need to plug it into a 4-ohm bass cabinet which can handle 300 Watts. If you plugged it into an 8-ohm cabinet, you might only get 200 Watts of power and probably less volume. If you plugged it into a 2-ohm cab, you’d get…FIRE! Don’t do that because there’s not enough resistance and the amp will overwork itself!

 

---

Do you want comprehensive bass lessons ... without overwhelm? Then subscribe below.

 

To get 2 lessons a WEEK (12 monthly installments of $38.86 USD)
click the PayPal Subscribe button
(There is no lock-in contract.)

You do not need a PayPal account to use the free and secure services of PayPal when you use your credit card or debit card

IMPORTANT: After your PayPal payment is complete, PayPal will automatically re-direct you to the confirmation/opt-in page so you can begin receiving your lessons right away. If the re-direct does not occur, please press the "Return to Merchant" button to receive the re-direct to your opt-in page.