I bought these new in Seattle in 2001. They are the original SRM450 made in Italy by RCF before Mackie moved production to china.
They require 120V USA mains power. You can run them in the UK from a 110v worksite isolating transformer. (that's what I have been doing).Since I liked them so much I brought them with me when I moved to the UK in 2003, but at the time it was impossible to get replacement 240v transformers so I ran them from a 240v-110v isolating transformer and this works fine apart from being an extra thing to take to gigs. They have been hardly used at all for the last 10 years as I haven't been gigging - and I think it is finally time to let them go. They've had extremely little use for their age. If I were still gigging I would use them quite happily.
Low price reflects the voltage issue, but these are great speakers! I still have the original boxes. The item "Mackie SRM450 Mark1 Pair Made in Italy by RCF USA power 120V" is in sale since Saturday, August 1, 2020. This item is in the category "Musical Instruments\Pro Audio Equipment\Speakers & Monitors".
The seller is "greenmanhumming" and is located in Crook. This item can be shipped to United Kingdom.