I found that after using the Entreq gear, it changed the character of my system sufficiently that changes elsewhere were subsequently necessary in order to fully enjoy the benefits of the Entreq gear whilst adjusting for the resulting changes in sonic character. I don't consider this a shortcoming of Entreq as much it was me setting up the system previously to compensate for existing shortcomings (there is no such thing as a perfect system in my book - nothing is perfect though the best systems obviously come extremely close).
Prior to using the Entreq gear my system lacked overall resolution when playing CD (in relative terms - not absolute) and whilst the bass was OK in relative terms to the rest of the spectrum, it lacked resolution to an even greater extent to the rest of the spectrum (especially treble) which sometimes made it annoying and overly warm - almost like a bass-reflex speaker put in a large room with too much reflection. Mind you, many titles I own were not effected but titles from record labels known for prominent bass such as Reference Recordings and also Decca classical releases from the late analogue era in the 70s were the ones where the effects were most annoying.
But my previous "tweaking" of the system resulted in me using an Audioquest Yosemite interconnect cable for a couple of years. This cable is extremely clear (for mid-priced copper) but it does not resolve like high end silver does, the top end is very benign and friendly to bad source material as opposed to being surgically precise and the bass tends to be very warm compared to a direct connection. It is the sort of cable you would use in a system that tended towards bright and grainy because it is such a good antidote in these cases and it is a good antidote if a lot of the recordings in your library are mediocre. After adding the Entreq gear, however, the system no longer needed the sort of compensation afforded by using the Yosemite cable because the Entreq gear removed those last traces of grain and the clarity became sufficient in it's own right. I was then left with a system that was too warm, too polite and a bit too fat sounding even though the Entreq had improved resolution, improved timbre, improved imaging and removed the last of the grain. But as soon as I bought a Wireworld Gold Eclipse (pure silver), everything was not only nicely balanced once again, but all the benefits of the Entreq gear were preserved.
On the other hand, if I remove the Entreq gear, the Wireworld Gold Eclipse no longer synergises well with the system because it tilts the spectrum the wrong way. It becomes grainier and leaner and these things are accentuated by the silver interconnect.
So for me at least it is all about synergy and a lot of experimentation is required. I would be willing to bet that you could achieve exactly what you want by finding the right combination of the earthing cables and interconnect cables and possibly mains cables as well. But I realise this is expensive. It is far too expensive an exercise for me and I think some of what I achieved was something halfway between a well-educated guess of the end result and a minor fluke (but I only say fluke because I got it right the second time around and the total cost was "only" the Entreq gear and the new interconnect).
In my opinion, in itself the Entreq gear cannot "wreck" the bass on a system. But like any other component you add, it will change the character and that may or may not point the system in the direction you want. As I say, I could go back to a copper interconnect and I would not like my system for some of the time (but it would be OK a lot of the time too). But I want it right all of the time if possible, no matter whether I am playing a recording made in 1958 by DGG or a Reference Recording made last year. So I would much rather fork out for the silver interconnect than go back to a system with the copper interconnect and no Entreq. Because the Entreq with the Wireworld pure silver is a step up in quality that belies the price I paid for those two products.
