Q: What are the common ohm ratings for guitar speaker cabinets?
A: The common ohm ratings are 16, 8, and 4 ohms. It is important to look at the cabinet inputs to correctly match the rating for your setup to ensure the optimal output and performance of your amplifier. While some ohm mismatches are acceptable, other ohm mismatches can cause failure in your amplifier's power amp section.
REMEMBER: Resistance is measured in ohms. Resistance determines how much current will flow through a component. A very high resistance allows a small amount of current to flow (i.e. a 16 ohm speaker load draws less current than an 8 ohm amp is ready to supply, but it will work safely). A very low resistance allows a large amount of current to flow (i.e. a 4 ohm speaker load draws too much current from an 8 ohm amp, ultimately overheating the amp).
Unacceptable Ohm Mismatches: When connecting any amplifier to an external cabinet it is important to keep in mind that the ohm load of your cabinet should not be lower in number than the ohm rating of your amplifier (which can cause the amplifier to fail). I.e. - If the amp output has an overall rating of 8 ohms DO NOT run with an external cab that has an overall rating of 4 ohms.
Acceptable Ohm Mismatches: It is acceptable to run the overall ohm load output of an amplifier to a cabinet that is higher in number. I.e. If your amp output has an overall output rating of 8 ohms you can run into an external cabinet that has an overall rating of 16 ohms. Be aware that you will lose ~15-20 percent of perceived volume with solid state power amplifiers when running this type of ohm mismatch, but you will suffer no failures.
Q: Can I run two cabinets with different ohm ratings?
A: We do not recommend running cabinets with different ohm ratings, as it may create an ohm load that your amplifier will not recognize and can possibly damage the power amp output section.
Q: How do I connect my Line 6 amplifier to the external speaker cabinet?
A: Your manual should explain most situations you would run into. Feel free to contact us and ask questions re: specific setups not covered in the manual and we will add them to this document. For example:
Q: Can I run my Line 6 amplifier without a speaker load (i.e. not connected to a speaker)
A: All Line 6 amplifiers (with the exception of the Spider valve series) are safe to run without any speaker load connected. The DT series and Spider Valve series amps **must have a speaker load connected to avoid damage to the output transformer.**
Spider II, III, IV Cabinet Wiring
- The Spider II & III HD150s are set up with 8 ohm stereo outputs to match the Spider cabs. You will want to use two speaker cables to connect to both jacks of the cabinet. If you do not connect both speaker outputs to an 8 ohm load (or higher) you can suffer a power amp failure.
- Spider II & III HD75s runs 4 ohms mono. You will want to use two speaker cables to run the 8 ohms stereo cabinet from the head to the cab (creating a 4 ohm load) If you only use one cable, you may only get two of the four speakers to function.
- Please consult the labeling on the cabinet or use a multi-meter to measure the ohm rating to ensure you will not induce failure with an incorrect connection.
Q: Is there a video tutorial where I can see different cabinet connection options?
A: Line 6 Head and Cabinet Connections
Q: I am running my Spider HD with a cabinet from a different manufacturer which has a different ohm configuration that what the Spider HD needs. What can I do?
A: Please see the previous information on acceptable ohm mismatches. If the ohm mismatch is not acceptable you may need to have your cabinet modified to conform to the needs of the Spider HD series. Please have this modification performed at your nearest Line 6 Service Center.Service Center.
Q: What are the wattage outputs and ohm loads on the Line 6 amplifiers not already discussed?
Vetta/Vetta II HD
Flextone II HD
200W 2X12:4/8/16 ohms