balanced vs. unbalanced

[Babaluma]

in his book "mastering audio", mastering engineer bob katz recommends unbalanced lines over balanced lines when the cable length will remain short. i am just wondering - "why?"

i have my mackie 1202 vlz (ok, i know it's a piece of shit but it has served me well and i can't afford to upgrade to an A&H just yet...) hooked up to my active yamaha msp5 monitors (i love them) via a balanced trs to neutrik cable. i am just wondering if i might notice an improvement in audio quality if i switch to the unbalanced input on the monitors...

any guesses/ideas?

tia,

gregg

[lickthestar]

only one way to find out. btw, I wouldn't consider the vlz a piece of crap.

[rhythm ranch]

It's unlikely to make a difference in the audio quality going to your monitors.

Balanced/unbalanced has less to do with the quality of the actual audio signal and more to do with rejecting extraneous noise/signals. For short runs, cables are less susceptible to noise and you may be able to not use balanced. It also depends on your electro-magnetic environment. When I had my studio in Brooklyn there was a hell of a lot more noise floating around the atmosphere than here in New Mexico (the UFO fly-bys are random and only occasional, so I don't count them).

Plus, unbalnced cables are, in general, cheaper!

[lobstman]

Unbalanced outputs are cleaner than balanced outs because in order to balance a signal, you need to go through additional circuitry or a transformer. Look at the schematic of any* preamp, from a John Hardy M1 to your Mackie- the signal comes out of the amplification stage unbalanced. In the case of output transformers, folks sometimes like the coloration they add, but it's coloration nonetheless.

It's a tradeoff though, because unbalanced lines are more susceptible to picking up noise, so you have to judge the cost/benefit of balanced to unbalanced on a case by case basis. I'm in the planning stages of building a rack of simple preamps, and I'm going to make them unbalanced and keep my cable runs to about three feet.

As for your monitoring setup, try it and see.







*I'm sure there's an exception somewhere that runs fully balanced internally, but 99% of the preamps out there work as I've described.

[hammertime]

I didn't read that whole mastering book, but I just read another of his articles (I'll try to find the link), and he recommends going unbalanced into a mackie (in a kind of cryptic way), primarily because those mixers don't have as much headroom as they claim. He points out that the solid state amps start sounding edgy when you start pushing them, so sometimes -10 makes sense for monitoring and mixing. Personally, I monitor out of the mackie at -10 and make most of my connections unbalanced.

in his book "mastering audio", mastering engineer bob katz recommends unbalanced lines over balanced lines when the cable length will remain short. i am just wondering - "why?"

i have my mackie 1202 vlz (ok, i know it's a piece of shit but it has served me well and i can't afford to upgrade to an A&H just yet...) hooked up to my active yamaha msp5 monitors (i love them) via a balanced trs to neutrik cable. i am just wondering if i might notice an improvement in audio quality if i switch to the unbalanced input on the monitors...

any guesses/ideas?

tia,

gregg

[hammertime]

Here's the article, read the paragraph "how much headroom is enough." At least that's what I extrapolated from the article.
http://www.digido.com/portal/pmodule_id ... age_id=36/

[philbo]

Balanced is most useful on low-level signals, like mics.

With line levels (such as you'd feed to a powered monitor) you will probably not realize any benefits unless you are:
a) Running REALLY long lines to the speakers, and
b) In an environment with extremely high electrical noise.
________
Yamaha dt400

[Babaluma]

hey all,

thanks for the informed replies, it has really helped me to understand.

i will get some new decent quality short unbalanced cables and see if it makes a difference - will let you all know!

[Professor]

Interesting. My first thought was to say that most of the sonic benefits of unbalanced cables comes from the fact that there is less circuitry involved in the output & input circuitry on the two devices.
With very, very few exceptions, audio electronics runs unbalanced internally (of course, I do own a couple exceptions). In order to balance the outputs, the signal is split and inverted on one side of the split, usually these days through an op-amp circuit, but sometimes also through a transformer. At the next input, the signal is re-inverted on one side and then summed together, again through either an op-amp or a transformer. Noise picked up along the cable's journey is magically cancelled, but the circuitry itself may introduce some noise of it's own.
So that's the trade-off... which isn't necessary to make if you are not running your lines in a particularly hostile environment.

The problem I saw, though, is that if you simply use an unbalanced TS cable on the same outputs from your Mackie, then you're still going through the circuitry but not getting the benefit of the balanced cable run. Indeed, you're getting the worst of both possibilities.

But then I read that bit about the amplifier circuitry within the inexpensive boards not being up to snuff, and I think that's a pretty darn good point. Running at "unbalanced levels", namely -10dB, would make sense because it keeps you a little further away from that higher noise floor at the top of the amplifier circuit's capabilities. But that's a different consideration than running "unbalanced wires" out of connections that are built to go either direction - as are all the 1/4" connections on Mackie gear. (except inserts)

So my take on it would be, if you are going to run from an exclusively unbalanced output like the RCA outs into RCA inputs on your next device, then that's great. If you can run your inputs into the board at -10dB levels, that's great too, and whether you're using balanced or unbalanced wiring, aim for the lower levels of the -10dB signals to maintain more headroom and the lower noise floor on those op-amp circuits.
At that point, I really doubt the cable construction will make any kind of noticeable difference unless the environment is noisy or the cable quality is significantly different.

-Jeremy

[Theron D]

The Avalon M5 mic pre is like this too, with the output unbalanced, Avalon told me the same thing - keep the cable very short and the unbalanced will actually be the "purer signal" since it does not have go through an output transformer.... (note there is a Jensen transformer option to balance the output). So far I run unbalanced, about a 1 meter cable, no complaints.

Theron D

Unbalanced outputs are cleaner than balanced outs because in order to balance a signal, you need to go through additional circuitry or a transformer. Look at the schematic of any* preamp, from a John Hardy M1 to your Mackie- the signal comes out of the amplification stage unbalanced. In the case of output transformers, folks sometimes like the coloration they add, but it's coloration nonetheless.

It's a tradeoff though, because unbalanced lines are more susceptible to picking up noise, so you have to judge the cost/benefit of balanced to unbalanced on a case by case basis. I'm in the planning stages of building a rack of simple preamps, and I'm going to make them unbalanced and keep my cable runs to about three feet.

As for your monitoring setup, try it and see.







*I'm sure there's an exception somewhere that runs fully balanced internally, but 99% of the preamps out there work as I've described.

[BAM]

Great thread. I am *so* impressed with the very fine people who post on this board and the knowledge they so willingly share.

[Babaluma]

well, i tried it! i replaced the balanced cables with unbalanced ones, and...

the output to the active msp5 monitors at a given monitor gain was MUCH higher. as my control room gain pot on the mackie was already very sensitive (i always leave the monitors internal amp gain at maximum - i heard this was best for sound quality/headroom), changing the leads made it even more sensitive, so that the room volume was way too loud at the minutest pot settings...

needless to say, i changed back to the balanced cables, ha ha! i couldn't notice any real difference in sound quality - the balanced perhaps being a little less noisy, but that could have been due to the gain difference.

[vvv]

i always leave the monitors internal amp gain at maximum - i heard this was best for sound quality/headroom

That doesn't seem correct...

Output volume knobs set at higher than approximately 50% (sometimes even lower) typically seem to allow the output amps to distort...

[Electricide]

i always leave the monitors internal amp gain at maximum - i heard this was best for sound quality/headroom

That doesn't seem correct...

Output volume knobs set at higher than approximately 50% (sometimes even lower) typically seem to allow the output amps to distort...

yeah, get a sine wave going, or some pink noise, and adjust the gain consecutively...ic pre, mixer channel, the outputs of the mixer, then the amp. Gain staging is usually done in this way to minimize amplification noise.

Now, if one component is much noisier, you may decide to reduce the gain on that one, and then boost the gain in the next component, but I'd wager that the results would be marginally beneficial

[Babaluma]

that's strange, i have heard from a couple of people that it's best to leave your amp or active monitors on full gain at all times, and then control the actual volume level from your mixer's control room gain pot...

i would be interested to know if i'm wrong about this, as i am meticulous about correct gain staging throughout the rest of my audio chain.

so, you're saying it might be better for audio quality (less distortion), to set everything at the correct gain setting and then slowly raise the msp5's gain controls until i can hear distortion on a 1Khz sine wave, for example?

any more info/advice much appreciated!