Scott Henderson Discussion

[nigel]

Hi Scott,
another (probably stupid) question about a 2x12 cabinet with Celestion G12-65 speakers:-) You recommended to have an 8 ohms output on a 2x12 speaker cabinet...that would mean to use two 16 ohm speakers, right? The Celestion G12-65 are only available with 8 or 15 ohms.

So...can I use two 15 ohm speakers to run the amp with 8 ohms?

Greetings,
Thorsten

[Scott Henderson]

Yes that's correct - speakers always measure a bit lower than even numbers. If you measure an 8 ohm cab, the reading is usually around 7 ohms.

[nigel]

Ok...so it would be no problem to plug the 8 ohm output of the amp into a cabinet with two 15 ohm speakers?

[nigel]

Sorry for my "double check asking"...I just don't want to blow up the amp or cabinet;-)

[Scott Henderson]

Yes, two 16 (really 15) ohm speakers wired in parallel equals 8 ohms. Parallel means that the positive from the jack goes to the positive on both speakers, and negative from the jack goes to the negative on both speakers.

After wiring a cabinet it's important to do a battery test. Plug a guitar cable into the cabinet's jack so you can still see the speakers. Touch a 9v battery to the other end of the cable - rest the negative shaft of the plug on the negative side of the battery and then touch the positive tip of the plug to the positive side of the battery. You should see both speakers move slightly to the front of the cabinet. If they move in different directions, you wired it wrong, or someone fell asleep on the job at the speaker factory.

[nigel]

Thank you very much for the detailed explanation Scott:-)