Kz, your use of the term "combo" implies that the amplifier in the 705 is somehow inherently defective, since the M60s alone are quite accurate. If you got this "brightness" notion from reading posts on some other forum, you should disregard it and keep in mind that much of the audio discussion on the internet is a quagmire of misinformation. The 705 amplifier, along with all other competently designed units, amplifies transparently without a hint of the substantial frequency response inaccuracy that would be necessary for it to give an audible coloration to the sound. Colorations won't be found there, but rather in the recorded material which is being played. The tone or EQ controls are to compensate for poor material, not an ineptly designed amplifier.
The 705, if you like its features and it fits your budget, should be excellent with the M60 or other Axiom speakers.
