48kHz vs 96kHz: audible?

From my experience I'd suggest any differences being heard are coming from the conversion process of altering bit rates rather than the rates.

In other words do not convert bit rates.

Perhaps there is some equipment that can do it without downgrading the sound quality. 

@tomcy6  is correct. 
 

The reason oversampling gives the impression that it may sound better is not due to the oversampling process itself but due to the fact that at higher sample rates, filter artifacts are pushed to higher frequencies which you cannot hear. If a standard CD player employs very good filters (more expensive to build than oversampling), they would sound just as good.

There have been multiple suggestions here that Media Center may not be performing the conversion well. That certainly seems a plausible explanation, but my perception of jRiver is that they know what they are doing. However, I'll raise this issue on the jRiver forum and report back here.

oldaudiophile: by "background," I am referred to what has my primary attention. I am working at a drafting table with my primary attention directed to what I am working on there. The speakers have been aimed and the subwoofer adjusted for this spot using instrumentation.

tomic601: I haven't visited 2L yet but shall soon.

For those who are interested, here is my update, mostly empirical:

After researching the sample rate conversion capability of jRiver Media Center (MC) via query on the jRiver forum and researching related discussions there, I have arrived at a likely evaluation of my experience, from the following possibilities:

1) It has been suggested that the sample rate conversion of MC is substandard. The consensus I have researched does not support this suggestion, and MC users feel that it is very good. By default, SSRC sample rate conversion is enabled, with SoX being an optional method. There is some debate on which method is superior, but the MC publishers recommend SSRC as the default, while providing SoX as a checkbox alternative. There is considerable discussion there about the audible differences between the two, and apparently, there is none, whereas there is allegedly and inaudible measurable difference. But I don't know who measured it and what their capabilities were.

I have not been able to find any 3rd-party analysis of a comparison of the two methods. In my case, the default (SSRC) was active, and SoX was not enabled.

2) It has been suggested that digital audio is likely to sound its best when played back at its native rate. That has been my experience with other recordings beyond the scope of this thread, but in this case, the native rate is unknown. I don't know at what rate this digital recording of The Planets was made or mastered, and I don't know whether the rate of the release is at that native rate. HDTracks, from whom the files are downloaded, does not provide this data, and they make no claims to provide products in their native rates. (They "offer what the publisher sends them," they effectively informed me some time ago in response to a different query.) However, in my opinion, this suggestion is certainly plausible.

3) MC sample rate conversion is effective (which seems probable given their history and experience), and I can indeed hear the difference between 96kHz and 48kHz. Whether this is due to the accuracy of the data, or to the digital filters employed for each rate, I cannot say.

So, I have concluded, for myself, that the difference is indeed audible, and that difference may be a result of a combination of #2 and/or #3 above. I do not feel compelled to explore other comparisons (other players, other DAC's, SSRC/SoX ABX), so it is possible that I am not a very dedicated audiophile. At this time, I am content to identify and play files at their native rates as best as I can.

I have some Blu Ray concert discs that are inexplicably cut off at 48.  They are clearly inferior to their 96 bretheran