When will we ever hear turntables demoed fairly?

I would take away another message, Bruce.

You can get good sound, but it takes diligence. Beware.

Lots of retailers can show you good sound. Some can show you the difference between a cheap system, a good system, and a great system. Small differences may be elusive, and some retailers may try to promote the highly merchandized / high margin units, but with some diligence you can get mighty good sound. Perhaps not the ultimate - that's the work of decades of trial and error.

brucegel

You are pretty close to it. That is one big reason you see so much stuff being sold here on anon. The reviews are great, the ads look cool, gear has no distortion according to the measurements. Should sound perfect. But wait, the bass is flabby and activates the walls, the MC cartridge sounds bright forward and thin, the amp sounds grainy,

I usually start with a speaker that I like and try to build on that. Not that speaker with the shiny cones with cool looking folds in them and the highest grade parts in the crossover but rather the ones that have less crossover with larger midrange drivers that add realism to male vocals and cellos etc. 

Just rambling here. 

****So my final takeaway on my original question is that you can't achieve any real comparison that means anything objectively.****

Your premise is not quite true.   There is value in comparing tables with different arms and carts on them.  There are characteristics of sound that are primarily influenced by a turntable's speed stability which can be perceived no matter what arm or cartridge is on it.  Rotational stability is probably THE most important aspect of reproduced sound as this affects the rhythm and feeling in music.  We tend to focus on frequency response related issues and "detail", and not as much on speed stability.  Good speed stability affects soundstaging and our perception of detail and overall tonality as well.  I think you are correct that a thorough comparison cannot be made with different arms and cart, but paying close attention to speed stability is a darn good place to start.

Yes, Frogman, right on. There is another aspect. Platter mat and record interact, it's like kind of sandwich. Can one hear the differences of this? Experienced good ear can. I myself probably cannot but may still have a feeling that something of that is not quite correct if it is the case.

So true. In the golden age of consumer turntables looks and price was everything. But the problem was the construction of the units. Most units were plastic, or vinyl covered MDF. Better units were cast aluminum. Both of these have there own problems as far a sound is concerned. Most classic units were never made to be very musical in the first place. To have a "musical" capable unit would mean large size and great mass. Not many consumer units weighed over 20 pounds. From my experience the heavier the better. I have found a turntable needs to be 40 or more, this was recently confirmed by Technics with the new 1200GEA model weighing 40 pounds! You can then compare a turntable to a piano or any musical instrument. You cannot expect a budget priced piano to sound the same a Grand Steinway piano. They may both produce sound and have the same basic parts to function, but if you want the sound of a Steinway, you know what to expect when you buy one. So either a turntable can sound musical or it cannot. It depends on how well it's made, and how well it can isolate the platter and tonearm from being influenced from outside vibration. One key factor is keeping the acoustical energy concentrated on the tonearm section. When a turntable is built correctly, the tonearm is then free to keep the signal true and musical. Case in point: Technics SL-1200MK2 series. Many people are familiar with this model that has been around since the late 70's, virtually unchanged. There was one major change only after the first few years or production. The lower section of the turntable was originally a one piece heavy/thick rubber, latter changed to a weighted inner hard compound section and a thin rubber shell to replace the original design, and few noticed. BUT it also killed the sound quality too. So in order for me to make a very musical turntable from the classic 1200MK series I use an all wood design for the base and fill the special made voids with sand for loads of internal dampening for a neutral low resonance tone and high resistance to feedback. Constructing separate sections for the motor and or tonearm (depending on design) that is built from wood with it's own sand filled chambers that can be isolated via sorbothane bushings. The results are stunning when compared to a stock 1200MK in a side by side comparison. You could spend insane amounts of money for "upgrades" to be added to a 1200MK2 that in reality give little to no sound benefit because they do not address the main problem of construction and lack of damping in the platter that rings like a gong, to a tonearm that is mounted metal-to-metal with no isolation. I address all these issues in building a musical turntable and the results speak for them self. Remember, you can put a $1k cartridge on a $300 turntable, but that will not make it sound like a $1300 turntable. Thanks, Roy (roylcraft)