How do I tell how many Ohms my subwoofer is?

[Silgalias]

Heya Folks,

So I have this subwoofer. Its from a digital a/v receiver home cinema setup by a Spanish company called Vieta, the VR6100 with the Neo 10 surround system.
Despite being over 20 years old now it is actually not at all bad and I decided to use it in my new system at least for the time being.
I have however one problem and that is my amp does not have a dedicated output so I am connecting via speaker line as the subwoofer has a variety of input options.
But do I connect to the 4 Ohm or 8 Ohm line out on my amp?
Is there an easy way to test how many Ohms a speaker is working off?
There is no external indication on the subwoofer itself nor in the original manuals tech specs. It does mention that the rest of the surround speakers are 6 Ohm just no mention of the subwoofer.
If I assume that the subwoofer is also 6 Ohm should I then connect it to the 8 Ohm output?
Thanks.

 

[RayDunzl]

If the subwoofer has its own amplifier, the input impedance should be quite high.

1000 or 10,000 ohms or more would be my guess.

The sub would be sensing voltage, not drawing power.

So, in that case, it really won't matter, connect to the 8 ohm speaker output.

Stick the leads of an ohmmeter (if you have one) across the input terminals and get a rough estimate.

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If the sub doesn't have an amplifier (no A/C power cord to the sub), the 4 ohm speaker lead would be the safer (not by much) choice.

 

[Holmz]

 

[Silgalias]

It's a powered subwoofer.

 

[Holmz]

You picture was a good idea.
(It is a powered amp.)

So if those speaker level inputs are showing 10k ohms, then they draw nothing from the amplfier but the voltage as a reference.

Try it on 8 ohm and use the gain knob.
You can always move it to the 4 ohm side too.

 

[Silgalias]

Thank you.