turntable location

I'm in the process of upgrading my VPI HW 19 MK2 with a new tonearm and cartridge. Once done I'm facing a classic dilemma. Do I place the TT on a rack located between my Merlin VSM's, with a correspondingly short interconnects, or would I be better off to place TT behind a short wall 12 ft away with long interconnects? I know the advantage of short intercon's but what about all the harmonic vibration from the speakers? Seems as that would have a significant influence.
Good question.

Personally, I try to avoid really long interconnects. But if you go this way, be sure the interconnects are properly shielded with good grounding options.

Can you try the closer location first? Maybe you will not experience any vibration problems.

While the HW 19 Mark II has a somewhat basic spring suspension system, it may be possible to tune it with spacers in the springs etc to further reduce acoustic feedback.

Or you could try supplementary suspension devices, like Vibrapods underneath or the Gingko Audio Cloud platforms.

Good luck.
The last place you want to place a turntable is between speakers. While any rack, baring an electron microscope platform, will add vibration, it is the least of your problems. What will 'excite' your turntable more so is the acoustic energy that flies around the room as your speakers play, especially hitting the cartridge. See for yourself by putting the turntable in another room or isolated space. You will be surprised at the difference. But there is hope, as I am working on an acoustical shield for turntables that solve 95% of the problem. Coming to soon, at a reasonable price.
What Buconero said is quite so -- that airborne vibrations can be a a greater problem. A good dustcover can help somewhat here. The HW 19 Mark II usually comes with a good custom hinged dustcover that rests on the wooden base and is not in contact with the spring suspended plinth, table and arm. I hope you have one of those.

One great asset of Audiogon is the pics of all the members' systems. Perhaps you might take a quick look and see where many of them have chosen to locate their turntables. My impression from the pics I have seen is that a good number of them are located in front, between the speakers. Others are located along the side wall, not too far from the front. Some of them have special suspension supplements that might serve to reduce the vibration problem.