RCA vs XLR which would say is the BEST?????


Here is the system:
1. Merlin TSM-M (right/center/left)
2. Axiom QS 8 rear channels (right/left)
3. (2) Earthquake Supernovas MKIV
4. Satori Shotgun Bi-Wire Speaker Cable (right/center/left)
5. Arcam DV 27 (no xlr connection only coax/optical/analog)
6. Bryston SP-1 Pre/Pro (coming with XLR connections)
7. Bryston 9BST amp (coming with XLR connections)

Now I need to connect the SP-1 to the 9BST so do I use RCAs or XLRs? I can do the in either .5 or 1 meter. I have enough RCAs to do the job now and I would have to buy the XLRs. I only want to do this once (right how many times have I said that in this hobby) so your advice will be welcomed. Which should it be?????
hammerfilms
A lot depends on what gear you want. There is a lot of great gear out there that does not come with XLR connections. If you can use XLR's and it is truely balanced then go for it. Definitely do it for very long runs. I agree that for short runs, you probably won't notice much of anything if any at all.
I have heard some positive differences using balanced connections for 1m runs vs. same kind of cable single-ended. I don't think anyone can really know this answer short of you trying it out for yourself, despite your wanting to "...only do this once". To me, if you want to know for sure, you'll have to bite the bullet and experiment (just make sure to match volume levels to compensate for balanced's hotter output). At least buying cables on Audiogon if you're so inclined, you probably won't have to worry about taking a hit in the wallet when you go to sell the loser.
Having read all the posts above and found nothing to contend with, I would consider Zaike's post the most reasonable., simply because there is no objective "BEST" . Your ears will have to decide....just my 2cents ..Cheers,
Question?????????????

Can this be done, shouldn't be done, or you can but it will sound like #%$@!!!??

Seeing that I have five speakers (Left/center/right/ and two rears) and only three single xlrs (at this time) can I run the left/center/right in balance mode and the two rears with rcas in an unbalanced mode? Or is this one of those either or things? I truly want to do this right and it looks that the xlr way is the one. What do you think?
Well a potential problem doing this is XLR's do indeed generally produce a 3db gain over RCA's , so you may find yourself in a situation where the fronts over power the rears. Of course adjustments can be made on your preamp, but that can be a little tricky. I use an all balanced system so I know the benefit of XLR cables , but in your case, my guess is they are not necessary. However that being said, you will always wonder what your fronts sound like with XLR's , so see if you can borrow some. In some systems XLR's are provided, but only as a marketing ploy.
Many Rotel owners, for example, prefer there amps hooked up single ended.