What does impedance mean?

Impedance is the load connecting to the speaker socket on the amplifier or combo to give the maximum power transference. The impedance of the speaker and amplifier must match to avoid causing damage to your unit.

How can I find out the impedance of my cabinet?

You should be able to find the model number and rating plate on the back of your cabinet. If you cannot see this then you’ll need to have the impedance measured by an engineer. Impedance ratings for current cabinets can also be found in the product sections of this website. Alternatively, you can email us and we will do our best to help you.

Can I change the impedance of my cabinet?

Below you can find information on what the impedance can be changed to in different cabinets. If you would like to change the impedance of your cabinet then get in touch with a qualified engineer who can carry this work out for you.

4x12”  with 16 Ohm Speakers: 4 Ohm mono, 8 Ohm stereo, 16 Ohm mono

4x12” with 8 Ohm Speakers: 2 Ohm mono, 4 Ohm stereo, 8 Om mono, 16 Ohm stereo

2x12” with 16 Ohm Speakers: 8 Ohm mono, 16 Ohm stereo

2x12” with 8 Ohm Speakers: 4 Ohm mono, 8 Ohm stereo, 16 Ohm mono

Which impedance speakers do I need to work with my amplifier?

The impedance of your cabinet always needs to match the impedance of your amplifier. This information can be found on the back of your units. Valve amplifiers usually have an impedance selector or different speaker sockets for different impedances.

Can I convert my cabinet to stereo?

Any 2x12” or 4x12” cabinet can be converted so long as the impedance of the amplifier and cabinet match. This work must be carried out by a qualified engineer.

What extension cabinet will work with my combo?

You can find details of our combos and the matching extension cabinets on our website. Visit the support section to download the user manuals. You can also test out the combos and cabinets at your local Marshall Dealer.

Where can I buy the old style impedance selector for my amplifier?

Old style selectors are no longer available. We would recommend speaking to a qualified engineer to fit a new rotary selector.

Does the user manual have the different impedance settings in it?

Most of our user manuals show you where to connect the speakers and how to set the impedance. Visit the support section to download our user manuals.