Let’s Check the Ohm Rating of a Guitar Speaker Cabinet With a Multimeter

A good number of speakers are rated 6-ohm, 16-ohm, or 4-ohm. For this reason, it’s advisable to know the type, owned by your cab or guitar. Ohms are impedance that tells the amount of power that a speaker can draw.

For our case, we will teach you how to check the ohm rating of a guitar speaker cabinet with a multimeter. Finding the impedance of your speaker is necessary and you can achieve this by dividing the voltage by current. Well, for such information, we urge you to go through our entire discussion.

Connecting a 4 ohm speaker to an amplifier that only supports 6 ohm speakers, more power will be drained. More power is necessary in allowing it to easily sound loud. Well, with your multimeter, let’s see how to check the ohm rating of your guitar speaker cabinet.

What is the ohm rating of a guitar speaker?What is the ohm rating of a guitar speaker

The rating here simply implies the impedance of any speaker. Therefore this is the total resistance of the voice coil of the speaker to the current flow, rated in ohms. Unlike a typical electrical conductor, the wire winding of the voice coil develops a loop, famously known as inductance. This is a new term which differs from resistance and changes based on the frequency.

Ultimate guide on how to check the ohm rating of a guitar speaker cabinet with a multimeterhow to check tbe ohm rating of a guitar speaker cabinet with a multimeter

You don’t have to worry about the process because below are simplified steps to direct you. Of course you have to create some time and assemble necessities. Here we go;

Step 1: Gathering essential materials and tools

From the title, you can realize that we have already mentioned one of the most critical tools. One of the best tools to be considered here is a multimeter. Alternatively, you can opt for a digital multimeter or a 9-v battery. Besides, you should also remember to have a screwdriver for unscrewing and clipping some connectors or clips.

Step 2: Connecting the multimeter probes to respective speaker cables

Connecting the multimeter probes to respective speaker cables
source: https://www.sweetwater.com/

Under this step, you are supposed to attach the black wire to the negative and red probe to the + ve input of the multimeter. If not, your job will be to ensure it reads the ohms function. If everything is in place, you can go on and set up the multimeter. 

More so, it’s advisable to make sure that the testing tools are in good working condition before testing the ohm rating of your guitar speaker cabinet.  While linking the wires, confirm whether the meter reads zero or not; correct it. You are discouraged working with multimeters that already have some readings.

Step 3: Unplugging the speaker

Unless you want to end up with minor injuries but you are supposed to disconnect your speaker from the power source. For this reason, you should try to locate the lead wires, stretching to the terminal on the speaker’s cone and the wires, connecting to the guitar jack. You need to be careful while unplugging the guitar speaker from the power source and never regret this process.

Step 4: Removing the wires

If possible, the next step will be detaching the input wires. You should only attempt this action after you are sure that the speaker is off and disconnected from the power source. While removing the wires, you should label them based on positive or negative. You don’t have to worry when it comes to removing the wires because it is a breeze. You simply have to twist the connectors/clips to discharge them.

Step 5: Linking the speaker wires

There is nothing much to worry about under this step because it is straightforward. After detaching the wires from the guitar speaker cab, it’s now time to form a closed circuit, which is achieved by connecting the wires together. While twisting the wires, you are supposed to exert less pressure. For instance, the closed circuit should help you to check the ohm rating of your guitar speaker cabinet.

Step 6: Checking the ohm ratingChecking the ohm rating

After all the above steps are successful, it’s now time to check the ohm rating of your guitar speaker cabinet. Now the multimeter’s probes should be attached to the respective terminals of your guitar speaker cabinet. I would advise you to carry out this process on steady wires for accurate readings. Sometimes the wires of your speaker can be broken, and therefore when tested, it can show infinite resistance.

For such cases, I would recommend replacing the wires with more compatible ones from a trusted supplier. If after testing the speaker and it displays resistance, just know that it’s in good working condition. Take the readings, displayed on the multimeter screen and round it off. The figures you will see on the screen will be the ohm rating of your guitar speaker cabinet.

How can the impedance of a speaker affect sound?How can the impedance of a speaker affect sound

Wrong speaker impedance may cause several harms like;

  • In case you mix and match 8-ohm woofers and 4-ohm tweeters, it’s possible that the mismatched and sometimes may not produce quality sound. This is because the power will increase since the volume levels of these devices are not equal.
  • Connecting speakers with wrong impedance on speaker crossovers may adversely affect the frequency of the crossover. Therefore, the sound output will also be dramatically affected. You are also likely to experience distortions with your speakers; unpleasant for your ears.


What will happen if I have unbalanced speaker impedance?

Higher impedance cannot damage your equipment, but it’s associated with reduced power. This will therefore force you to play music at low volumes. On the other hand, lower than expected impedance speakers can make your amplifier extremely suffer from permanent damage and heating.

Final words

You can agree with me that apart from observing the ohm rating of your guitar speaker cabinet, you can still use a multimeter and arrive home. That’s what we have tried to put across in our above discussions. Use our knowledge to determine the guitar speaker rating for compatibility reasons. 

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