mdfoy -
I have little doubt you are hearing a difference. The question you pose is "why"?
The problem is, you know what changes you are making and that can have a significant influence on what you are hearing. Your brain is very powerful in that regard. Like I said, I am sure you are hearing it. The question is, without knowing any of the details, would others hear the same thing?
Here is a simple test...
Get two friends, one of whom has fairly good listening skills (not necessarily an audiophile, but someone who listens well). Tell both of them that they are going to conduct a series of twenty short listening tests. DO NOT tell them about your experience or what you are testing. The less they know, the better.
Then give the friend with the listening skills a sheet with the numbers 1 - 20 and tell him that in each test, he will simply listen to see if the volume seems louder, there is more clarity and the bass has more power than in the previous test. If so, he should place a "+" character after the number of the test. If it is not louder with greater clarity and deeper bass, he should place a "-" character next to the test number. If he simply cannot tell, have him record a "-". As soon as he is able to record an answer, that particular test segment can be concluded and they can move on to the next segment. This is all this person should know about the test.
Show your other friend how to connect the speaker cables to each set of binding posts. Explain to him that after each test, he will pull the speaker cables out of the binding posts and insert them in the same OR other set of binding posts for the next listening test. In other words, he will either change binding posts or he will not. Provide him with a pen and paper to record the position of the speaker cables in each test. (If you are very careful not to touch the speaker wires together and short things out, you can actually make this change without turning anything off. So the change can be very quick. This is not recommended, but we do it all the time.)
As for the "directional" jumpers, leave them oriented for use in the top set of binding posts. Although I doubt it will make any difference, if there is indeed any directionality, it should make the difference between the tests even more dramatic and will favor the top binding posts.
Once everyone understands what they are to do, you leave the room until the test is complete.
Once the test is complete, if there is indeed a difference, there should be a high correlation of "+" marks to instances of the speaker cables being placed in the upper pair of binding posts (and vice versa). My guess is that it will be relatively random. But it would be interesting to see if that is the case.
On many occasions in the past, I was very sure things made a significant difference. But even doing a simple blind test with myself as the listener, the tests did not correlate very well with what I was convinced was the case.
This is not a scientific test by any means. Rather, it is just a quick and dirty test to see if others will hear the same thing you are hearing wihtout the influence of knowing what you know. Whether or not they do will help us get closer to the answer to your question.
If you take the time to do this, please report back and let us know the results.
- Jim
