Speaker Cab Wiring - Suggestions Needed

frown

Hi All,

I'm after some confirmation that my planned wiring makes sense and is safe, for an upcoming project.

I have a Vox Lil Night Train head, with a single speaker output rated at 8 Ohm / 1.5W and 16 Ohm / 2W.

I've got a couple of vintage speakers that I am planning on using in a customised cab [an old electric heater casing] and being cautious of old speakers [Whiteley Stentorians], I'm wanting to try and wire it so it's at the correct impedance - ideally for both speakers, but also should one fail, hence a parallel wiring circuit. I've thought to use a trio of 4 Ohm resistors with each 4 Ohm speaker to create 16 Ohms, with the idea being that if one speaker fails, the remaining  components automatically becomes series and at a safe impedance.

Does my thinking make sense? Or am I best of just wiring in series and crossing my fingers? I could ultimately add a switch in there so I can toggle between the series / parallel sounds, but that's for later on when I've established the speakers work properly!

Sketch below should visualise my plan - any suggestions or advice appreciated!

Circles = 4 Ohm / 5 W speakers
ZigZags = 4 Ohm / 25 W aluminium resistors

soma1975

I like how you've drawn how you planned to drive off in a car after you've wired the cab. 

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ICBM

I would just wire them in series. At 8 ohms they will only get 0.75W each which should be completely safe for 5W speakers, even old and fragile ones. Resistors will simply waste a lot of the power.

frown

Thanks ICBM - less is more yet again!

Simplest circuit is most likely the way I'll go. It's not the end of the world if the speakers do go as they are old and didn't cost me much. Would be nice to have everything co-ordinated though, as they're gold enamel, which is colour co-ordinated with the amp itself and the enclosure I have for them. The resistors would be gold too if I end up doing that.

I'll use crocodile clips to test things first [when the second speaker finally arrives...], then go from there.