Old Bose speakers and lossless audio

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I'm think of getting a new amp such as a Sony DG910 or Onkyo TS-SR605 so that I can hear the lossless audio on blu-ray. I have a 7-year-old Acoustimass 6 series II speaker set from Bose. It's their 5.1 system with 5 single-cube speakers and a base unit.

Would these speakers be high enough quality for me to hear the difference with lossless audio? If PCM still sounds the same as DTS or Dolby Pro Logic then I might have to think about upgrading speakers too.