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Spider II 4X12 Cab (Slanted) - Correct Impedance Selection
by defleepard on 2009-12-23 04:08:29

I have a Hiwatt DG103 100 Watt head with (4, 8, and 16 Ohm) impedence selector. My cabinet is a Spider II 4x12 Slanted Cab. There are two speaker inputs on the back (one for left and right) at 8 Ohms each. I understand that the total Ohm load for a cabinet is based on whether the speakers are Series, Parallel or both. Considering I don't know whether my cabinet is Series, Parallel or Series/Parallel, I don't know what my impedance setting should be set to on my Hiwatt head (4, 8 or 16 Ohm). This is very important since I can risk overheating my amp or not generating enough volume through the speaker cabinet. Can you please shed some light on this? I also attached pictures (front and back) of the Hiwatt Head and Spider II Cab that I own. Thanks.

Re: Spider II 4X12 Cab (Slanted) - Correct Impedance Selection
by Nick_Mattocks on 2009-12-23 06:02:15


According to the picture you posted of the label on the back of your amp, the cabinet is 8 ohms per side in stereo (both jacks connected) or 4 ohms if you plug a single speaker lead from your amp into the right hand socket as marked.  You should set your amp to 4ohms output.  Your cabinet is wired in parallel when it's used in mono.


Re: Spider II 4X12 Cab (Slanted) - Correct Impedance Selection
by defleepard on 2009-12-24 05:46:20

Thanks for the information. I realized the picture I posted of the back of the cab might have not been my model (I found that one off the internet). This time I attached an actual picture of my amp. After speaking with a technician at Line 6, he informed me that there is an older model of the Spider II 4X12 Cab. In this sense, it is wired differently (Parallel vs. Series with one input used). In my case, if I am using only the left speaker input, then I should still be getting 8 Ohms impedance instead of 4 Ohms. I attached two pictures this time. Old and New. The first one which is old, is an actual picture of my my model amp. The second one must be the newer model. The difference is that the old isn't labeled "Stereo" for both 8 ohm inputs combined and doesn't have the 4 ohms mono selection for just the left speaker input. Please clarify if I am correct or not because I have talked to so many people about this and I am tempted to go buy a multimeter to find out for myself. Thanks!

Re: Spider II 4X12 Cab (Slanted) - Correct Impedance Selection
by Nick_Mattocks on 2009-12-24 07:33:01


The OLD picture shows two independent inputs for the two pairs of speakers and it looks like it's always in stereo.   BUT - a multi-test meter is only a few quid or dollars and is a real asset to have for all kinds of stuff, and testing what you have would be one way of determining the actual impedance(s) of your cab and whether the left and right input jacks are wired together internally.  To me though as I said it looks like the cab has two sides.

If the cab is an older model anyway and out of warranty, I'd simply take the back off and have a look at the wiring and the labels on the back of the speakers which should state the impedance somewhere.  That's probably the easiest thing to do if you don't currently have a meter to hand.

If it is the case as the picture seems to suggest that there are two independently wired pairs of speakers the answer is easy (provided nothing has been swapped out of the cabinet and that the speakers are all 16 ohm speakers wired in parallel in two distinctly separate sets of two ):  IF that is the case, you need to use two leads from your cab in parallel to your amp and make sure that it is set to 4 ohms.

These cabs are made for Spider heads which are stereo and output set at 8 ohms per side, so I think it's a pretty good bet that the cab is permanently set for stereo operation at 8 ohms per side.


Merry Christmas


RE: Spider II 4X12 Cab (Slanted) - Correct Impedance Selection
by AndyParedes on 2010-01-08 09:42:17


The spider 4X12 cabinet has two separate 8 ohm loads, so you will want to connect both jacks to the head (to get all 4 speakers to work) and put the head at 4 ohms. See the following links for more information:

Cabinet Connection and Ohm F.A.Q.

Video Tutorial: Line 6 Head and Cabinet Connections

The information above may not be current, and you should direct questions to the current forum or review the manual.