A bit of data here. Gnarlsagan sent me his current two tenores for comparison. Here are my findings.
One of his sets sounds the same as my four sets. That's five similar sets that are reference in sound.
However, his other set really surprised me by how obvious the difference was. I'm not talking about "oh it's a little less bass", I put them in expecting to either hear a slight difference or no difference. But I was shocked. The only comparison I can make would be to a telephone type sound. Not that bad of course, but everything under 400hz was noticeably lower resulting in an almost bassless sound.
I do find that inserting them very deeply with the right tips brings back most of the reference sound of the other sets. Which brings up some interesting questions as to what is causing these acoustic differences. Needless to say, I put them on my a/b switch and started some side by side comparisons and used EQ to compensate the bass light pair so they sound like the reference pair. This is a very very close approximation (as much as a/b switching allows) of the difference in bass:
That's at least 7db of bass difference!!! That's huge!. As gnarlsagan describes, he had a few "warm" or "bassy" pairs. At least one of which he said was approximately the same difference in the opposite direction. With this being true, it is very clear why some people are finding them not as detailed, not as dynamic sounding, not neutral, etc. If you are getting +7 db with everything below 400hz that is a huge difference. I mean, deeeeeum.
So the best advice I can give, is that you compare your tenores to something like the er4s or hd600 and use the "overall" tone and sound as a reference. If your tenore sounds noticeably bassier or warmer than you probably have a "bassy" pair. If you hear something extremely similar in neutrality to the hd600 or er4s, but with very linear bass, at least close to neutral, then you probably have a reference set. I pity the fool that gets the bass light set. ;) The one nice thing about them is that it offers a more reference sound when inserted deeply. So if you prefer deep fits they might be great. Otherwise, the treble sounds essentially unchanged between sets. I can't hear any noticeable difference above 400hz on any of them when the bass is EQ'd to the same levels. In fact I was listening to his bass light pair for a while and forgot it was said pair, because i had the EQ applied.
Regarding the "reference" sets I have. All five sets sound identical in every way. Identical bass as far as I can tell, at least within .5db from low to high. This makes me believe this is probably the target of the tenores. Whereas other sets seem to not be consistently identical. For instance, gnarlsagan's warm sets weren't the same level of bass between them. I'm guessing there are components that are inconsistent with the bass reproduction level.
Again, this is still a very small pool of data. We're talking 7 or 8 so sets between us two and then maybe 20 or so on the thread here that might vary, out of possible thousands? That's probably less than 0.5% of sets. However, it is obvious that there are differences out there either way. So, as before, I just recommend you compare them to sets as mentioned to get an idea how far off your bass level is, if at all. It's definitely worth trying to get a reference pair. You could buy 6 tenores for the price of one er4s. And if you get one good set you did good in my opinion. Obviously not everyone will agree, but hopefully it wouldn't take that many and you could return the others. But value wise, they are excellent no matter what. Just some thoughts.
I'll post some impressions of various tips he sent me as well. Still going through them...
p.s. You might want to try a -7db low shelf filter if you find your set bassy. If that makes them sound uber reference you know you probably want to try for another set (unless you enjoy the bass that is) :)
Edited by luisdent - 6/13/14 at 9:34pm