Vocal booth is 15 meters away from control room. How to extend signal without loss?

[MDM]

Hi,

Right now I have my setup right next to the recording booth.
I would like to move the setup (think: AD converters) 15 meters away from it's current position.
Is there a way to do this and not losing signal?
How far can I extend the Mic input, and can I put something in between (a DI or something) to ensure a solid signal?

Any advice very welcome - thanks,

MDM

[Dan Kennedy]

Mic signals are good for 100 meters, no sweat, with good, like Belden, not stupidly expensive like Monster.

Don't worry about it.

Those who claim that the wire makes a stupendous difference have something to sell. Those who claim it makes a small difference in some situations, and can explain it are telling you the truth.

I do believe in good cables. But a good song is worth infinitely more...

[norman_nomad]

I'll certainly agree with Dan, but I'll say that depending on where you live you may run into extra RF noise.

I live in SF near a large radio tower and once I moved my vocal setup about 50ft from the control room I was getting a lot more noise.

To remedy the situation I brought the preamp into the vocal booth and ran the lineout from the pre into the control room. For whatever reason this cut down the noise bigtime.

[MDM]

Thats what I thought: leave a preamp in/close to the vocal booth.

[Kingtone]

you should be fine...
if not...

get the singer to sing just a bit louder.

[mixer]

thicker string on the soup cans,

[tcause]

Originally Posted by MDM

Thats what I thought: leave a preamp in/close to the vocal booth.

Tick. Pre near booth... Run line level as far as you like and then some.

[Jonboy79]

I have many runs over 20 meters and have no problems. In fact my vocal cable run is probably near 50 meters and the quality is no less than it was when it was 5 meters. However I do use fairly high quality cables.

[DeepSpace]

With properly terminated balanced lines and decent stock cable (Canare, Mogami, Belden etc), a run of 15 metres should present absolutely no problem.

If you are getting perceptible noise, signal loss or artefacts over that distance (or even several times that distance) then you have a fault condition in the mic, the cabling or the desk/pre/DI at the other end. In which case, it is not the distance but the fault you should be focusing on.

[pkautzsch]

Originally Posted by MDM

Thats what I thought: leave a preamp in/close to the vocal booth.

Having to walk over 15 metres to the booth to adjust the pre's gain would be way too much walking for me. Solid cabling is the key, and one can read that even 300 metres are still ok. One might have to consider impedance issues when using those cable lengths: The lower the mic's impedance and the higher the pre's impedance, the better. Schoeps mics, for example, as they are used in a lot of radio station remote stuff at least in Europe, are 35 Ohms if I remember correctly.

[norman_nomad]

Originally Posted by DarkSky

With properly terminated balanced lines and decent stock cable (Canare, Mogami, Belden etc), a run of 15 metres should present absolutely no problem.

If you are getting perceptible noise, signal loss or artefacts over that distance (or even several times that distance) then you have a fault condition in the mic, the cabling or the desk/pre/DI at the other end. In which case, it is not the distance but the fault you should be focusing on.

RF is a real world issue that proper termination won't totally remedy in all situations. Such as being within a quarter mile of a gigantic radio/tv tower.

Sutro Tower - Wikipedia, the free encyclopedia

Couple that with a low gain mic like the SM7, and when you crank the gain on your pre after a 50ft mic cable run you DO hear a perceptible increase in noise vs line level running the same distance.

My 50ft mic line signal was almost unusable (noise around -40dbfs) vs. my line out level using the same cable, same converter, same preamp gain (-75dbfs) which is more usable.

[DeepSpace]

Originally Posted by norman_nomad

RF is a real world issue that proper termination won't totally remedy in all situations. Such as being within a quarter mile of a gigantic radio/tv tower.

Sutro Tower - Wikipedia, the free encyclopedia

Couple that with a low gain mic like the SM7, and when you crank the gain on your pre after a 50ft mic cable run you DO hear a perceptible increase in noise vs line level running the same distance.

My 50ft mic line signal was almost unusable (noise around -40dbfs) vs. my line out level using the same cable, same converter, same preamp gain (-75dbfs) which is more usable.

While I've never had the pleasure of wiring a studio that was less than a quarter mile from the Sutro Tower, it's been my real world experience that the effectiveness of common mode rejection in differential circuits with quality cables is not dependent on the amplitude or proxmity of the source of interference.

If we were talking about unbalanced lines, then it's a whole different story.

[The Byre]

A balanced mic cable will run to 150m without any degradation of signal, unless you are VERY close to a transmission tower or similar.

[norman_nomad]

Originally Posted by DarkSky

While I've never had the pleasure of wiring a studio that was less than a quarter mile from the Sutro Tower, it's been my real world experience that the effectiveness of common mode rejection in differential circuits with quality cables is not dependent on the amplitude or proxmity of the source of interference.

If we were talking about unbalanced lines, then it's a whole different story.

Yes. Fair enough. I consider my situation to be uniquely crappy in terms of interference. I didn't, at first, expect cable length to make a difference but it did. Using standard Mogami quad cable. Balanced connections throughout.

But hey. At least I get about a dozen tv channels without having to pay for cable. And my radio reception is crystal clear!

[DeepSpace]

Originally Posted by norman_nomad

...But hey. At least I get about a dozen tv channels without having to pay for cable. And my radio reception is crystal clear!

LOL. Unexpected side "benefits"! Heh!