What's better: RCA or XLR?

Joeb asked what was better RCA or XLR connectors. In high end audio, sound/music qualities are paramount, so that should be the primary consideration. No? Prior to purchase of ICs, I discussed this issue with a Synergistic Research Tech., and he said he preferred the more organic, rounder, more liquid and "whole" sound of RCA ICs. But he also said that most (not all) of the people he worked with, and were into audio, used and preferred XLR connectors.

I had no preconceived biases for one over the other, and having both fully balanced pre-amp and pre-amp (also single ended), I tried both (SF Line 2 and McCormack DNA2 DX). I found that music with the different ICs (same model though) was as the Syn. Res. Tech described it, and that XLR sounded dryer, leaner, and more detailed (musically). I ended up purchasing RCA ICs for the music quality/character. My ICs were only 40".

As to the robustness of the plug and connection security, I would prefer XLR, but that is seldom a problem in home audio. There are advantages for pro use though, and especially if long runs are used. In fairness to the XLR terminals though, I did not give them much of a chance to break in whereas the RCA terminals were well broken in.

IMO, the only valid comparison should be A to B of the same ICs in RCA and XLR and with well known music. Try it and see. As to professionals using only XLR, well, they have professional reasons, but musically these pros produce some really excellent recordings, and they also produce some really lousy recordings. But I don't really believe the end product is very dependent upon the type of IC used. Cheers. Craig.

Great post Craig, must try listening for what you describe.
Cheers,

I fully agreed with Madisonears and SFstereo. Your equipement MUST be balanced from input to output to realise the benefits of XLR over RCA.

Let's be clear about XLR & Balanced first.

The XLR is a *type* of connector.

It could be used for almost anything, and has been. It was developed as an audio connector for 3 wire balanced signals.

The RCA is a *type* of connector.

It could be used for almost any use, and has. It was developed as a consumer type coaxial connector.

The reason some RCA plugs and jacks used for *audio* today are more expensive than XLRs (built mostly for pro audio and broadcast) is simple enough. The XLRs are made in very large quantities and not of exotic materials (possibly excepting one XLR intended for high-end audio I saw). Whereas the RCA components you see for high-end audio use are made in relatively small quantities and use exotic metals and/or platings and insulators (teflon for example).

Similarly, the construction and manufacture of finished cables for *high-end audio* is also a low quantity process utilizing high cost components when compared to commercial cables made for the broadcast and pro audio industry, so the prices are higher in general.

The use of *balanced* lines for audio is another matter entirely. The use of balanced lines for audio gives you a reduction in potential noise and hum due to something called CMRR (common mode rejection ratio) which is the cancelling of signals that are impressed upon the wire (picked up) from external sources (hum, noise, RF, etc.).

(CMRR is *not* an attribute of the wire, but of the receiving circuitry - if the circuitry doesn't do this right, or is not balanced electronically, the CMRR degenerates back to no better than single ended, or worse)

The single ended connection does not have this immunity and depends upon sheilding alone. Often this is not a problem since in practice this is a problem under two circumstances:
1. Loooonnnnngggg runs of wire
2. Low levels of signal over longish runs

The second is found with microphones (similar to phono carts in signal levels) to be a significant problem. A typical PA system or studio must because of the physical requirements have very long runs with signals of all levels going back and forth. So runs of as much as a hundred feet or more are not unusual. Contrast that with the 1m run between your CD and preamp!

Studios and PA systems use 600 ohm balanced lines to overcome the problems of hum & noise as well as HF rolloff over a long cable run.

Which is better? In theory the balanced cable is better when driven with a balanced signal and recieved with a balanced input,better yet if it is also 600 ohms (low Z).

In practice this also means *more components* and more "things" for the signal to pass through, so may not actually be better, or worse than the RCA/single ended cable IN THE APPLICATION we are discussing (your system).

_-_-bear

Thanks to all who responded. the technical viewpoint is relevant, however, my main concern is, as someone suggested, the difference in the "quality of the sound". There seems to be so many different views on both sides of the question. My only experience with cables is this. I have a pair of Harmonic Tech XLR pro-silway from amp to pre, and it replaced a cheap set of rca's. I heard no difference, although I must admit I didn't do a lot of critical listening comparing the 2. However, when I replaced the cheap rca's from cd player to pre-amp with a set of Cardas quadlink 5c RCA ends there was a noticeable improvement.
thanks, joe