I've been listening to the same combination of a Denon DRA-625 receiver and Celestion 100 speakers resting on very solid Chicago iron stands for the past 17 years, and am now seriously working to upgrade my system. I love my Celestions and my old reliable Denon receiver (purchased for $500 in 1989, when $500 meant a lot to me). I especially like the Celestions' great ability to image and create a holographic soundstage, as well as the way they reproduce a solo voice. But they do have their limitations, particularly on big groups and massed sounds (one voice = great, symphonic choir = mushy).
One impetus to upgrade my old reliable system has been my purchase of an Olive Opus No.4 and a Cambridge DAC Magic, which have upped the ante on the quality of sources I can now listen too (i.e., hi-resolution downloads). This has got me thinking. Although even my current meager (but beloved) stereo ensemble is very definitely able to resolve clearly the differences between standard CD and hi resolution material -- which might encourage some to just relax and enjoy the improvements in sound -- there are some remaining sonic issues that have motivated me to upgrade SOMETHING in my system. These are (1) boomy, flabby sounding bass ... and by this, I mean, e.g., plucked bass violin just sounding like an amorphous "whoomp"; (2) tinny-sounding high end, that makes things like cymbals and triangles and sound out of this world, but seems to add a "shine" like an aluminum Christmas tree to the harmonics on most instruments. I also don't like the way the string section sounds through this system on most symphonic recordings.
Anyway, I can't afford to chuck it all and start over, but I could afford to replace either the Celestion 100 speakers or the Denon DRA-625 receiver. With a budget of $2,000 to $3,000, which one would YOU replace first, and with what? One last note, it's a small listening room (10 X 20, with 9' ceilings). Just for a reference point, on the amplification end, I've been looking at the NAD M3. Thanks for your thoughts on this, folks.