Apple Logic Pro /LogicExpress Discussion

thanks a lot for the long answer.  they are powered - tannoy reveal 
active.  guess I'll look to the shielded balanced cables...

Michael

On Dec 30, 2004, at 9:39 PM, Howard Lipp wrote:

> Michael,
>  
> There are a lot of considerations for your situation without all of 
> the info I will give you my best.
>  
> I foresee three scenarios from your description.
>  
> 1-If they are powered audio monitors and the power cables run
>      along with the digi001 inputs and monitor inputs,
>      then you have induced line hum from the power
>     cables being picked up by the inputs of the digi001.
>      or by the monitor inputs for this scenario you need
>      to use shielded balanced cables to your monitors
>     and shielded balanced cables to your digi001
>  
> 2-If you are talking about video monitors and the power
>      cables and digital video cables are run along with your
>      digi001 inputs then you may have digital sync buzz being
>      picked up possibly along with induced line hum
>      for this you will also need to use shielded balanced cables
>     for the monitor inputs and the digi001 inputs
>  
> 3-The third scenario is the worst possible. It would imply that
>      you have a ground loop between your powered monitors
>      and the source of your audio(your computer)?
>      or a ground loop between the power for anything
>      connected to your audio path
>     for this you will need to make sure that anything
>      connected to your audio including your computer
>     is on a common ground because not all grounded outlets
>      in a home or business are at the same ground potential
>     it could be something as simple as this
> You have cable TV and you also use your television for monitoring the
> ntsc video which you sync to picture everytime you hook up the video
>  to the tv everything hums. discovered the ground loop was the cable 
> tv input to my
> monitor. I'm not saying this is the problem but it illustrates the 
> example.
> A similar scenario. You have your computer powered from an outlet over 
> here
> and you power your speakers from an outlet over there. Try powerring 
> everything from
> one source.
>  
>  
> If your monitors allow for it, you can use balanced instead of 
> unbalanced cables
>  they remove common mode noise (line induced hum) This is a pretty 
> inexpensive
>  option. Otherwise you will need very expensive shielded monster cables
> and they may or may not completely remove the problem.
>  
> Howard
> ----- Original Message -----
>  From: Michael Tuminello
> To: Logic_Cafe@...m
> Sent: 12/28/2004 7:02:46 AM
>  Subject: [Logic_Cafe] quick question: monitor hum
>
> Hey again -
>
> I am pretty much forced to run my cables to my monitors along with my
>  inputs to the digi001 along one wall in parallel, and I have a hum in
>  my monitors as a result.  (the cables are also not the best probably,
>  so that may be an additional consideration.)  the distance is 20 feet
>  max, probably closer to 15.
>
> thinking of dispatching with this hum once and for all as a birthday
>  present to myself.  any advice on the best (and cheapest) way to do 
> so?
>    are there cables that are well-shielded enough to remain silent 
> under
>  these conditions, or do I need some kind of hum-cancelling solution?
>
> Thanks -
>
> Michael
>
>
>
>
>
> Yahoo! Groups Sponsor
>
> ADVERTISEMENT
> <image.tiff>
> <image.tiff>
>
> Yahoo! Groups Links
>
> 	• 	To visit your group on the web, go to:
> http://groups.yahoo.com/group/Logic_Cafe/
>  
> 	• 	 To unsubscribe from this group, send an email to:
> Logic_Cafe-unsubscribe@yahoogroups.com
>  
> 	• 	 Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
> Service.
>
>