[Well, it seems like you & I could agree with a post on Sunday, by kenjit about speaker design (linked in a box below the end of this message). I found it very disappointing that so many negative posts were received on that thread. It appears to me that this forum is plagued by inexperienced posters, who take issue with subjects that they have not fully understood.]
I don't need a second pair of speakers, because I have found that I get the sound change I (very occasionally) need, by implementing a very simple, but effective change. I bypass my pre-amp and pug the XLR DAC cables direct into my power amp and control the volume on my DAC. Providing the DAC volume control is of very high quality, this change provides a slightly more detailed and dynamic sound (depending on how wet my grounding system is and how clean the main power supply is) with a slight loss of musicality and emotion.
I also find this change is sufficient to stimulate my perception of hearing and, effectively "wake up' my brain to figure out the new sound. I know this factor is playing the largest part in changing the entertainment value of my music.
Thank you,
BP