Hasn't it already been said that from a studio's view point signal isn't directional
'Directional' is the wrong word. The cables are constructed with the screen connected at one end only, hence the cable needs to be installed the correct way around. It has nothing to do with the 'flow' of the signal. It might be better to call the cables 'handed' or something similar.
What actual cable are you using, (Is the lead pre-made or did you make it yourself) as currently the description you are giving makes no electrical sense.
Alternatively post a link to it so that we can have a look at it.
This is not a 'balanced' cable where common mode interference on two conductors is nulled by either a centre tapped transformer or differential input, and I have no idea what 'pseudo balanced' is, but the argument for cables of this type goes something like this:
Using a balanced cable (two conductors in 'twisted pair' configuration and an overall screen) and two RCA plugs.
At one end of the cable connect one conductor (lets say red) to the tip of the RCA. Connect the screen and the other conductor (say black) to the screen of the RCA. At the other end of the cable, leave the screen unconnected, connect the red conductor to the RCA tip, the black conductor to the RCA screen. The argument is then that EM interference is induced equally into both conductors and is 'common mode' and nulled at the amp. The overall screen is only connected at one end, doesn't carry any signal and just provides EM screening.
Personally, I dont think it holds any water, but there you go....
Now I get you.
You are also correct in that it is a complete load of rubbish, in fact it sounds like somebody has picked up a little knowledge from Wikipedia, put 2 + 2 together and made 5.
Cables are a religion to some people. IMO the answers to the OP's question are:
1. Yes using balanced cables makes a difference, at least on paper, and quite often an audible difference. There are a lot of reasons for this other than the cable itself.
2. No it doesn't matter that much about the quality of the cable, provided it is of professional standard with good connectors. People will argue about this all day, but if it is a truly balanced connection, any noise introduced in the cable is being cancelled out anyway, this being the advantage of this kind of connection.
In a lot of equipment XLR may not be any better than RCA, that is true. But it's no worse and has less noisy plugs so why not.
Speaking of pro audio, you will never see a pro using an RCA cable. One of the reasons people get so obsessed with improving their RCA cables is presumeably because they are so rubbish to being with. My best component - my BAT preamp - does not even have RCA jacks. They were invented for gramophones in the 1940s, FFS. I just built my first amp, a little class T, and the blasted RCA jacks were responsible for more noise issues whilst I was working out the bugs than the rest of it combined.
The cable-obsessed dude that has been posting is right about one thing: if you want to have great cables, the best way to do it is build them yourself. It isn't that hard - not like building speakers or amps or whatever, it's just wires in a sleeve with some connectors - and there are kits with instructions as well. You can be as obsessive as you feel is necessary.
Living Room: Mac Mini, Oppo BDP95EU disc player, Benchmark DAC1, Balanced Audio Technology VK-50 SE preamp, McIntosh MC150 power amp, DIY 22 litre standmounts based on Scan-Speak 18W/8542, DIY subwoofer based on 15" Dayton Reference HF and a Hypex DS4.0 amp.
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Over short runs, in a domestic situation, there are no benefits to be had by using balanced interconnects instead of single ended connections.
On paper, what are the 'lots of reasons' you think make a difference?
Sorry for the slow reply - don't think you're still reading but I wanted to respond.
Your first statement is of such poor logic as to be absurd. I at least qualified my assertions about SQ with terms such as 'on paper' and 'quite often.' But you make an absolute statement, saying definitively that there are 'no benefits to be had' with balanced cables, if the cable runs are 'short' (normative; how short?) and in a 'domestic situation' (meaning the rules of physics change when I pass from work to home? What if I work from home?). An absolute unbending rule of nature based on two human-defined states.
And yes, I know what you mean. But the purpose of a balanced cable is to eliminate RF interference. My hifi stand currently contains - besides two amps, the Benchmark, and the Oppo - a PS3, a Wii, a Mac Mini, an Ethernet switch, several things charging in various USB ports and chargers, a couple of fused power strips, and a Sky receiver, all with a massive TV perched on top. This isn't even mentioning the electronic piano and all of the bloody rubbish with batteries and motors that my children leave in close proximity. My domestic situation may be smaller than the setup at the Fillmore East or the O2 Arena, but it surely creates RF noise and it's all crammed a lot closer together. And I may be a bit of a nerd but there's never been more RF interference in domestic situations.
As for 'short,' that can mean a lot of things. Having a look at the manual for my Benchmark DAC1 - useful since it's a piece of pro equipment and thus gives real data in their manual rather than the load of marketing rubbish we get from our usual friends - we can see that for a lot of these questions, the answers are too complex to answer with such a reductionist statement. The DAC1, using unattenuated balanced outputs, has an output impedance of 60 ohms and can drive 680 feet of cable. But if you use the -20db attenuator setting, which is what most 'domestic' users need to feed a consumer amp via XLRs, the output impedance rises to 500 ohms and the max cable length is 'only' 82 feet. You would expect the -10db setting to be in between, right? Not at all - at the middle setting the output impedance is 1600 ohms, and the max cable length only 26 feet.
All of this assumes a certain capacitance for the cables - this is all 'on paper' based on the design spec of the machine. But if you were using rubbish cables with high capacitance, it might not make a difference on a 300-foot cable run at the 0 db setting, but make the innocent change of attenuating the output slightly for a consumer amp, and the relatively small increase in capacitance of the cable - through the magic of multiplication - could shrink that 26 feet down to 2 or 3. Attenuate it another 10db and it probably stops mattering again.
In case you are wondering, the RCA outputs on the DAC1 are only 30 ohms and can drive a 1,360 foot unbalanced cable. These outputs are attenuated by around -10db as well - outside of the main, balanced circuit - to conform to the consumer audio standard. 30 ohms is great and you wouldn't expect too much sensitivity to RCA cable capacitance - you probably don't need super cables here. The signal is being padded and impedance corrected to deal with the high capacitance of consumer audio RCA inputs.
So this is the answer to your second question - what 'other factors' was I talking about. I mean, there are a lot of reasons balanced interconnects CAN sound better OTHER THAN the quality of the cable itself. There are a couple of examples: single ended RCA inputs have a high capacitance, and balanced audio equipment typically must pad or otherwise modify the signal sent to them. It's better to pass a balanced signal directly to another machine's balanced input. Obviously.
But I thought it was interesting that, in fact, the balanced outputs in general support shorter cable lengths than the unbalanced. Balanced cables are better. They send the signal on one lead, a true current-free ground on another, and an inverted signal on the other. At the receiving end, only difference between the signals is sensed - whatever signal is common to both leads is assumed to be noise, and rejected. It's built-in analogue error correction - called Common Mode Rejection.
But the superiority of XLR interconnects is more about the inferiority of deriving and sending unbalanced signals than the noise rejection. Note the the opposite is true as well. Some unbalanced consumer equipment is sold with an XLR output or two. These will tend to sound worse than the RCA for the same reason - it's a derived signal and thus you are adding an additional stage.
Balanced interconnects are used in professional situations primarily because of the length of cables enountered. The main problems are crosstalk with other cables, frequency response issues from transmission line effects on longer runs and baseband EM interference (most often mains hum). These are countered by having cables correctly terminated at their characteristic impedence (110 ohms), driving the cables at a higher signal level than domestic 'line level' and the use of differential transmission techniques.
Domestic connections dont really face these issues. I would guess that most audio interconnects are less than a couple of metres, and the cable effects I mention above aren't really significant.
Balanced has its downsides, the vast majority of equipment is not balanced internally and the use of balanced links involves two conversions from unbalanced to balanced and back again. This comes with cost and sound quality penalties.
So I stand by my analysis, in a domestic situation with short runs of cable, there are no benefits to be had by using balanced internconnects.
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