If I remember correctly, DefTech has a fairly bright and forward sounding characteristic. So this may be the sound you'll have to get use to. Some other way to "warm" the sound, just as your title suggests, adding a few blankets on reflective surfaces may help diffuse the sound a little. With bi-polar speakers, you also have to be very careful with your placement of it because you maybe getting too much reflection. One other option is to change your speaker cables and/or interconnect cables. Use "darker" sounding cables like Cardas may help things somewhat. Some people even find a difference between the type of digital cables they use. I don't know if you are using tos-link or digital coax but I think digital coax usually have somewhat warmer qualities to it too.