balanced/unbalanced quality difference

[jbonil1]

In case I can't use my balanced xlr inputs, is it the same if I record through the unbalanced inputs with my mic or there is a noticeable difference. I understand the difference between balanced and unbalanced is that balanced inputs have one more cable for eliminating noise, but, is there an extreme change in sound quality? My mic is a shure sm57. And just in case I buy a mic preamp, if I use the preamp through the unbalanced input would the sound quality be lost?

[petermiller]

the main problem is impedence. The unbalanced input would be a higher impedence therfore the mic would not be as hot thus raising the noise floor. If you ran it into a preamp first then took an unbalnced out from that on a short cable run you would have much better results.

[jbonil1]

I bought a behringer shark dsp110 for mic preamp, compressor and di. But still I have this question. Now with the shark if I connect the shark's balanced output to the dsp 2000 unbalanced output would the quality be lost?

[Rodger Hartlett]

i suggest using balanced cables and signal chains where you can . this would prevent any possibility of earth loop problems that often plague unbalanced connections.

[MOFO Pro]

Originally Posted by petermiller

the main problem is impedence.

He's right here...

Going from from balanced to unbalanced will just attenuate your source by 6 dB, not an impedence issue, just the result of using half the available signal path. Source will still sound fine at the lower level.

Impedence mis-matches will affect the entire spectrum of the source... decreasing signal strength, creating standing waves that add and subtract from your source signal at unprdictable frequencies... resulting in a dull... lifeless... almost painful final result...

[Treeline]

Double check the specs of the equipment you are using; you can't always assume the outputs are balanced.

[Robert D]

I'm not even shure what were talking about here. First it sounds like you're talking about using an unbalanced cable from mic to pre, thus the impedance issue raised.... then you said "Now with the shark if I connect the shark's balanced output to the dsp 2000 unbalanced output would the quality be lost?" I'm not sure where the typo is here...... one of those was supposed to be an input, not an output.... right? At least I think I got that it's after the preamp that you're asking about going un-balanced. If so, impedance isn't the issue, nor is earth loop problems. What you lose is common mode rejection. Balanced connections use 2 signal wires fed the same signal, but 180 deg out of phase with each other. If you sum the two signals together at the other end, they phase cancel each other. Any noise induced into the cable would be in phase though, and would increase with summing. But, if you phase invert one signal at the recieving end, and then sum, you end up with the now in phase signals adding with summing, and the now out of phase common mode noise being phase cancelled with summing.

[jbonil1]

Sorry, It'll go from the shark's balanced output to the dsp2000 unbalanced input.

[Harvey Gerst]

There are several methods of balancing a line; one of them involves impedance balancing, which still cancels out any induced noise when inverted, but the second line (pin 3) doesn't carry any audio signal. You don't get the 6dB boost from inverting.

Keep in mind this one simple fact: When your "balanced" signal goes into any of your rack boxes, it's immediately converted to an unbalanced signal for processing.

If there's also a balanced output on the box, it means there's also an extra stage, converting the now unbalanced signal back into a balanced signal.

So, your carefully balanced signal goes thru two additional stages in those boxes; one active stage to invert, combine, and unbalance the signal (so the box can do whatever it's gonna do to the signal), and a second active section to balance it again to make the trip out of the box - to the next box, where these additional i/o stages are repeated.

If your mic is plugged into a mic preamp, then a compressor, and maybe an eq, that's five additional conversion stages that aren't really needed - all they're doing is unbalancing and balancing the signal, over and over.

If all the equipment is reasonably close to each other, and you can run short cords, unbalanced routing actually wins over balanced. You should use balanced lines for long, low impedance runs, or when induced noise and hum may be a problem. For short runs to (and between) outboard gear, why add unneeded stages that can degrade your signal?

Don't take my word for it; try it yourself. Take the unbalanced output from your mic pre and run it unbalanced all the way to the recorder, thru any effects you want. Then take the same chain; use the balanced ins and outs, and listen to the difference. You tell me what you hear.

[PHILANDDON]

Harvey I read your reply carefully. I have a similar balanced to unbalanced question. I'm coming out of a preamp with balanced XLR outputs into a quarter inch tape recorder with unbalanced rca inputs. The units are close enough to each other to run very short cables. Should I simply run two short, high quality XLR to RCA chords, or do I need a line-level voltage converter? Hope I'm not hijacking this thread........

[Harvey Gerst]

Originally Posted by PHILANDDON

Harvey I read your reply carefully. I have a similar balanced to unbalanced question. I'm coming out of a preamp with balanced XLR outputs into a quarter inch tape recorder with unbalanced rca inputs. The units are close enough to each other to run very short cables. Should I simply run two short, high quality XLR to RCA chords, or do I need a line-level voltage converter? Hope I'm not hijacking this thread........

If the preamp has an unbalanced output as well, use that. If not, the balanced to unbalanced will work just fine although you'll lose the 6 dB gain of balanced levels. Tie the XLR Pin 3 and ground to the RCA ground, and XLR Pin 2 to the RCA center lead.

In our studio B, we run everything unbalanced with RCA plugs. The only exception is the mic inputs on all mic preamps (board pres and outboard pres).

[PHILANDDON]

Thanks Harvey. I found that very helpful!!

[i_looove_music]

I`ll buy SP B1 and Behringer MIC200. So, do I need balanced or unbalanced cable?(What`s the difference between balanced and unbalanced cable ) Do I need balanced cable from mic to preamp, and then 1/4 TRS cable from preamp to PC? And...Do I need new soundcard, because my soundcard doesn`t have 1/4 input... Pease help

thanks for answers