This is the second model in the new 600 Series to see a significant change to the driver complement. The outgoing HTM61 is a 3-way system, but only had a single bass driver. Here, we follow the line-up of the CM Centre 2, with two 6.5-in bass drivers and a smaller FST™ midrange. The Decoupled Double Dome Tweeter has also been moved upwards, to better align with the tweeters of the 683, which would make a great partner for this speaker in home theatre system. Like the HTM62, the ports are at the rear. This concept was retained for the centre speakers because of the more restrictive requirements on frontal area.