I am thinking that the DR100W used 8 ohms speaker, or, the power supply may not enough. When the DR100W comes with rated power supply (+/- 27Vdc) and load (4 ohm) , it should reach a minimum of 65Wrms/channel driven at input sensitivity (tested on 1KHz sinewave), this will not be true if the load is 8 ohms.
Even the TDA8950TH, the power rating is based on the 4 ohms load, also the TDA8953J - well, all these brothers are evaluated from 3 to 6 ohms load for SE, and 8 ohms load on BTL. We do not have measurement on SPL or power rating in functional music test.
If we have already a ready speaker, it is important to match this speaker to our amplifier - otherwise, we are expecting something from our power amplifier which cannot be attain.