When I hear mention of a "Reference system" or "Reference Speakers", I assume the terms are speaking about a system, (or speakers, as the case may be), that reproduces music in the upper percentage of a high-fidelity category for a given span of dollars spent.
In the higher (or highest) dollars spent for that particular group, the ‘reference system’ reproduces a flat, or near-flat sound reproduction without EQ enhancements and with a minimum of total harmonic distortion.
For example; within the higher (or highest) dollar category, I’m of the opinion that the McIntosh Power & Pre Amps would be a good baseline comparator.
They pretty much all have a rated THD of .005% from 250 milliwatts on up to the rated maximum power output. Those specification ratings would make the McIntosh line a “Reference System” for Class A/B & D amps.
In fact, I personally consider the specification of any McIntosh Power Amp and/or Pre-Amp to be a very good choice for the high-dollar category systems.
But not all of us have the tens of thousands of dollars needed to meet those specifications and match them with the additional comparable speaker system, turntable, cables, PSU conditioners, etc. etc.
As the saying goes, “A chain is only as strong as its weakest link”. Ergo, if you invest $6K in a Mac power amp and another $5.5K in a pre-amp, it doesn’t make sense to play your LPs on a ‘close-n-play’ turntable and ‘Walmart-brand’ speakers that you picked up in a clearinghouse special offer.
The problem is that even if you buy components that all fall among the same category of rated specs, there are so many variables that can be easily overlooked and the system can be ultimately mismatched as a result.
Frankly, it can get pretty crazy and quickly spiral out of control if one becomes obsessed and overly focused on each component’s speculations alone!
While most of us probably couldn’t afford to shell out $150K for a personal home stereo system, I knew of at least two people who took out loans, (one with a combined 2nd mortgage) for systems in the ‘top’ category.
I was much younger then and I’m pretty sure that at least one of them couldn’t afford anything close to what they bought were it not for his wife’s profession and earning power. Some years later I heard that they’d divorced over financial problems, (no surprise there).
So, IMO (and as several people have already intimated one way or the other), the “Reference System” has a ‘floating baseline’. It all comes down to a category/dollar-group that you can reasonably afford and ultimately, how well it sounds to you when you listen to it.
If you found that a collection of components you sampled sounded the best among all the other combinations in that cost category, that would be the “Reference system” to go by.
But regardless of the system you bought, if it sounds great to you for the money that you’ve spent to build it, then that’s all what really matters. Yes, you can bet that there are other people who have systems that sound better but you don’t need to satisfy them, just yourself.
FWIW,
Rich