Hi, on the back sticker is written 15 ohm, and 6 ohm on the B 110, these speakers are 15 ohm version, speakers posts look good but made of brass, a Cardas full copper will have make a much better contact and will have improved the sound greatly.Really nice find, And listen your the boss, best regards Yvan
Sorry Yvan, that is incorrect, here are the facts from a prior post of mine when Satch found the speakers:
Satch, congratulations on your score, its one most of us can only dream of. Hopefully, they are still working. As you may surmise, the black covering isn't correct, they are actually walnut or teak cabinets as evidenced by the chips on the front, and the color of the wood inside the area holding the grille, plus black paint drips on the back panel. There's the oddity of orange paint on the backs which suggest there's yet another bit of paint from some oddball previous owner.
However, the fact that you have matching serial numbers with AB matched is really nice as they are a matched pair. I will advise that these Rogers speakers are what the LS3/5a community calls "Psuedo-15 ohm". This is because in 1987, the LS3/5a's were redesigned by the BBC and KEF to use a newer and more consistent KEF B110 (the "C" model with spec number SP1228) and a new crossover using a resistive ladder and ferrite core inductors instead of the previous radio core inductors and autotransformer. This new design was still called the LS3/5a (many feel it should have been the LS3/5B). However, Rogers had not used up all their 15 ohm labels and continue to use them until their supply was exhausted and then moved over to correctly labeling them 11 ohm.
The 11 ohm and Psuedo 15 use the woofer which is smooth and shiny cone with a thinner and flatter PVC surround compared to the rounder and thicker looking Neoprene surround of the original and venerable 15 ohm's KEF B110 SP1003 woofer. The redesign brought the LS3/5a back into the middle of its spec range and many feel it sounds very good, with less nasality of older 15 ohm units that have slowly drifted out of spec due to aging effects on the mid-woofer. Both the 15 and 11 ohm still use the same T27 tweeter with protective grille.
You have some options as to how to consider restoring them, and that probably is a topic for a new thread either in Speakers or in British Audio forum where there are plenty of LS3/5a fans including myself. Hopefully, all the wear is cosmetic and the drivers and crossover are in working condition. If you do start a new thread, link it here so we can follow your progress.
Very similar to my brother finding a pair of LS3/5a's at a garage sale not 4 blocks from our mother's home after lunch. He paid $20 for the pair after remembering what I told him about Rogers and LS3/5a speakers. He's always the lucky one in the family.
By the way Satch, if you need any help with LS3/5a's, my deputy moderator of the Yahoo! LS3/5a Newsgroup lives in Amsterdam.
From memory, the Psuedo-15 ohm units ran from roughly SN 31 or 32000 to around 34000.