nice speaker, with a little workaround they sound fantastic. check the sealing, maybe it is changed to dust. check the bitumen panels on the inner sides of the cabinets, maybe they need some glue. needs better cables, other capacitors (jantzen cross caps are good enough, the original ITT- caps sound bad), bridge the switch and use other damping material (real wool damping from Visaton sounds great). there are two versions. an older with a black backside and newer with real wood veneer all around. both types have different crossovers. the MK1 crossover produces a difficult load for some amps and the MK2 has one more cap and bigger coils. the sealing material of the MK1 is much better and long term stable. I use a MK2 cabinet with the MK1 drivers and crossovers. it looks nicer and the MK1 crossover sounds better to me. the bass is more transparent, deeper and has more dynamic. if you find the right amp it will be hard to believe that such a old and cheap loudspeaker can sound so amazing. a tuned DM5 is a real high end loudspeaker system.