The HTM1 is the older version. The HTM3S "S" series are the latest version aluminum dome tweeter before B&W went to a diamond tweeter. With the "S" series, they were able to increase the resonance/breakup frequency of the aluminum dome tweeter to something like 28khz (if I remember right). This reduces the amount of breakup/distortion and brightness/harshness of the tweeter.
---
There are a few HTM3S speakers on ebay ranging from $1800 to $2500. The $2500 has the nicer wood finish and also a stand. There's one HTM1 for $1150, so it is going to be cheaper. It all depends on what you want to spend, but I would hold out for an HTM3S for the tweeter that is less harsh.
---
There are a few HTM3S speakers on ebay ranging from $1800 to $2500. The $2500 has the nicer wood finish and also a stand. There's one HTM1 for $1150, so it is going to be cheaper. It all depends on what you want to spend, but I would hold out for an HTM3S for the tweeter that is less harsh.