I've just ordered a Weber Mass 200 Attenuator. I already have 2 speaker cables at
1.5metres each, however the Weber website suggests to use cables no more than 4ft in length: http://www.tedweber.com/head-cab.htm
Do I really need to purchase shorter cables?

The instructions state:
1. Connect the speaker to the output of the MASS 200.
2. Connect the amp speaker output to the input of the MASS 200 with a short cable.

Does this mean I only have to get one short cable, for the attenuator to speaker or will I need a short cable for the amp head to attenuator as well.

It just says that because of potential noise issues. There's no harm in trying it, so just try it out and if its too noisy buy shorter cables.
Quote by Cathbard
Quote by Raijouta
Unless its electronic drums.

1.5 meters is not much longer than 4 feet anyways, you're fine

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