Balanced connection for domestic audio: does it make sense?

[charleski]

There are good reasons to use balanced connections in professional applications. You're looking at long runs (tens of meters or more) of cable that sometimes has to carry very low-level signals (such as for microphones), so noise immunity is an important concern, especially as cable placement is something you may not be able to control. But is there really any point in using them in a domestic setting? If your cables are 50-100cm and you're handling signals running at 0dBV (which is true of most DACs these days), then will you see any benefit at all from a balanced connection?

Obviously there are lots of subjective reasons to prefer balanced cables: they're 'professional', they've got big chunky man-sized connectors that lock in place with a satisfying click, equipment with balanced I/O will always cost more because it needs to handle twice the signal paths, etc. But if we're aspiring to be rational audiophiles, then none of this carries any water. I've noticed lots of comments in favour of balanced connection, but they really just seem an expression of preference. If balanced is really superior (in a domestic setting), it should be possible to measure this. Has anyone done that?

I suppose there might be certain situations in which you run into a ground-loop problem where a balanced connection offers a simple solution (though it amounts to avoiding the problem rather than removing it). But I've been using single-ended cables for 30 years without any issues, so I think that's a fairly rare and specific circumstance. I suppose people will be able to think of other sorts of anecdotal accounts, but I'm really interested in finding out if there's any data on this.

 

[DonH56]

The advantages of differential circuits in consumer applications are the same as in professional: greater SNR, lower distortion, greater rejection of common-mode noise, the ability to isolate the signal from the safety ground and provide greater resistance to RFI, etc. How much that matters depends upon the system and such. It some home systems it is the only viable solution; for most it probably does not matter.

 

[SIY]

There are good reasons to use balanced connections in professional applications. You're looking at long runs (tens of meters or more) of cable that sometimes has to carry very low-level signals (such as for microphones), so noise immunity is an important concern, especially as cable placement is something you may not be able to control. But is there really any point in using them in a domestic setting? If your cables are 50-100cm and you're handling signals running at 0dBV (which is true of most DACs these days), then will you see any benefit at all from a balanced connection?

Obviously there are lots of subjective reasons to prefer balanced cables: they're 'professional', they've got big chunky man-sized connectors that lock in place with a satisfying click, equipment with balanced I/O will always cost more because it needs to handle twice the signal paths, etc. But if we're aspiring to be rational audiophiles, then none of this carries any water. I've noticed lots of comments in favour of balanced connection, but they really just seem an expression of preference. If balanced is really superior (in a domestic setting), it should be possible to measure this. Has anyone done that?

I suppose there might be certain situations in which you run into a ground-loop problem where a balanced connection offers a simple solution (though it amounts to avoiding the problem rather than removing it). But I've been using single-ended cables for 30 years without any issues, so I think that's a fairly rare and specific circumstance. I suppose people will be able to think of other sorts of anecdotal accounts, but I'm really interested in finding out if there's any data on this.

As you said, it's just more foolproof. I can hook up a fully balanced system without ever having to chase down stray ground loops (assuming engineered components, of course). Where balanced is the most useful in home audio is where it's hardly ever used- phono stages.

 

[Wes]

Think of the term "Safety Margin" - and do you own any bonds in your portfolio...

It makes more sense as your cable runs get longer.

 

[Maki]

I suppose there might be certain situations in which you run into a ground-loop problem where a balanced connection offers a simple solution

Bingo. I used to have ground loop problems at my old place. Switching to balanced fixed it. I figured may as well, balanced gear is so cheap these days, at least for headphones and 4.4mm is standard on DAPs. It's not cheap to get custom cables but on the upside I can use 4.4 with almost all my gear without clunky adapters.

 

[digitalfrost]

Honestly I think balanced connections should've been the default if not for the lack of resources after WW2 that pushed everyone to make do with as little material as possible. It's really the unbalanced connections that are the odd ones.

 

[restorer-john]

I have no problem with balanced in home audio. I choose not to use it on gear that has XLRs in my collection as there is no benefit, actually the opposite. YMMV of course.

The Cannon XLR is a solid and positive connector for sure, but big, ugly and heavy. Whatever it hits, it will damage. It requires more circuitry at each end and potentially more residual noise, but that can be offset by picking up less. The net gain (no pun inteneded) may be improvement or the opposite.

On the measurement side, it's really useful, you have choices and can remove the common ground issues with amplifiers and multiple connected earthed pieces of test gear.

As SIY pointed out, it is inherently balanced sources such as phono cartridges that should have been balanced from day one, but weren't, and didn't we all have hum problems back in the day with single ended attached/earthed gear, huh?

 

[JeffGB]

I have both balanced and single ended dacs and amplifiers and in my high rise apartment there is a HUGE difference in noise. There are cell towers on the roof etc and I tried everything, including specially constructed cables but nothing eliminated the noise. The noise was specific to certain components though. I use a Schiit Heresy as a preamp after a creative g6 connected to a Crown XLS 1500 and that combination is terrible for noise. If I replace the Heresy with a different headphone amp (also single ended. Nuforce ICON HDP) used as preamp, the noise is almost completely gone with the same gain staging, so balanced isn't necessary with some components.

Balanced connectors (I don't know about the new balanced RCA plug from Khadas) have other advantages also. If you accidentally pull an RCA plug, the ground disconnects first, then the hot, which can lead to HUGE pulses if the volume is high. Balanced connectors disconnect the hot before the ground eliminating that possibility. I haven't found XLR cables expensive. I just buy them from our local music store.

I should add that I used single ended cables for 30 years in the same location without problem. I guess cell towers and other rf sources are much more prevalent today.

 

[josh358]

I had to chuckle -- measure it? The 60 Hz hum in my place would flatten an army!

As others point out, the importance of balanced lines is idiosyncratic: in some installations, hum can be a major problem, in others a minor one, in others, not a problem at all. But I've wrestled enough with hum in unbalanced gear over the years that I do my best to avoid unbalanced equipment. Why take a chance?

In any case, this isn't a golden ear audiophile issue, but a straightforward one -- it's something that's easily heard and measured. What's hard to predict is whether it will be a problem in your installation.

 

[richard12511]

As someone with a bad groundloop problem in my back sub, I wish I had balanced connections. Finding 11 channels with all the processing of modern AVRs is hard(expensive) if you're also looking for balanced connections.

 

[Chrispy]

It matters little if it makes sense to me or not I suppose, but having choices is nice otoh. I don't see all of consumer electronics shifting over to balanced due some relatively few who prefer it/need it tho. I've not needed balanced connections generally as I've not had any issues they might resolve that weren't resolved by solving a ground issue.

 

[Mnyb]

Historically there have been a bit to many not so good implementation of xlr in home equipment it’s just some cheap op amp tacked on and ta da you now have xlr as the big boys .

But it’s getting there . implementation is everything really . How the complete product or really the complete system is done is the ticket for me .

 

[jhaider]

Another advantage to balanced is that it opens up a world of pro gear. Sure, a BSS processor or Ashly amp etc will accept an unbalanced signal and play stuff. But you’re far more likely to get noise IME.

 

[polmuaddib]

I vote for balanced.
When you have complex system, it is very likely to pick up some ground loop.
Also, XLR provide more secure connection. Fells good when it clicks...

 

[Chrispy]

While we're at it, let's get rid of the lousy speaker terminal binding posts and go SpeakOn! Talk about satisfying clicks! Wrong thread?

 

[paulraphael]

While we're at it, let's get rid of the lousy speaker terminal binding posts and go SpeakOn! Talk about satisfying clicks! Wrong thread?

I've wondered if Speakon would show up in consumer audio. It inspires confidence. Maybe the cheap-looking plastic repels audiophiles? Neutrik should wise up and hand-carve a special edition from rainforest wood.

 

[Blumlein 88]

I would have thought perhaps TRS would have become the home audiophile balanced connector. Even better with some standardization this one connection could be used with both balanced and unbalanced gear.

I generally really like XLR connectors. But sometimes being gendered is a problem that you don't have with TRS. OTOH, sometimes having gendered ends is very good.

 

[JSmith]

But I've been using single-ended cables for 30 years without any issues, so I think that's a fairly rare and specific circumstance.

Agree... it depends on how the XLR has been implemented. @amirm has tested products that were terrible using XLR and fine using unbalanced, yet also the reverse. Many products tested though were similar on both, often XLR having a slight edge, but nothing to write home about.



JSmith

 

[charleski]

The advantages of differential circuits in consumer applications are the same as in professional: greater SNR, lower distortion, greater rejection of common-mode noise, the ability to isolate the signal from the safety ground and provide greater resistance to RFI, etc. How much that matters depends upon the system and such. It some home systems it is the only viable solution; for most it probably does not matter.

Lower distortion? There’s a blog post from Benchmark that states the opposite is the case for headphone outputs, as you have twice the number of amplifiers driving half the impedance. They still recommend balanced for line-level, but their claim of “substantial performance improvements” is somewhat vague and frustrating.

Balanced connections certainly promise better SNR, but what length of cable do you need for this to become significant? Sure, problems with the mains wiring can cause ground loops in some installations, but in the absence of a specific problem like that, how much would the SNR improve over a single-ended connection?

The one circumstance I can think of in which it would make sense to use balanced by default would be running long cables from a DAC to powered speakers through ducts that also contain power and network cabling. But then most active speakers only have balanced inputs anyway.

 

[tw99]

It also typically gives you 2x the output voltage, which can be useful.