# Are my ohms right?

Discussion in 'Amps and Cabs [BG]' started by bleachstained, Jul 16, 2001.

1. ### bleachstained

Apr 22, 2001
Here's my question. I have a crate 1x15 that handles 200 watts, and I am planning to get a hartke 2x10 that handles 150 watts.(Both cabinets rated at 8 ohms). For my amplifier I want to get a hartke 3500 that powers 350 watts at 4 ohms. So if I plugged both cabinets in would the power rating match exactly at 350 @ 4 ohms?

2. ### captainpabst

Mar 18, 2001
Tennessee
if both cabs are rated at 8 ohms like you say, then yes. 350w @ 4 ohms.

3. ### CYoung

Nov 30, 2000
Gainesville, FL
*WARNING*

Ok, the power handling is NOT additive. If you have a speaker that can handle 100W paralleled with a speaker that handles 300W, and they are the same impedance, you must make sure that the maximum power *per speaker* is less than the max for the lowest-power-handling speaker.

Explanation: electrical current and water flow are very similar. If you spilit the flow in a big water hose into two smaller hoses of equal size, you will ge about the same flow in each. If you take a 350W amp at full power into two 8 ohm cabs, the power will roughly be 175W per speaker. Now, it gets really weird if you are mixing cabs of different impedance.....I have no plans to try to show you tha math on that!

In your setup, at full power, you may get 175W into the 150W cab. This *could* be a problem. In the real world, as long as you are not pushing the amp right near the limit, you will probably be ok. I doubt seriously you will in actuality be anywhere close to full power.

4. ### Rockin John

I'm with CYoung. Whilst the total impedance of the two cabs in parallel might enable the amp to develop its full power, there's a danger of overdriving the 150 Watt cab.

Rockin John