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Author Topic: Snake vs Home Runs: What makes sense?  (Read 5991 times)

Brad Weber

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Re: Patchbays
« Reply #10 on: July 26, 2011, 07:52:40 am »

While patchbays have been used in studios for ages, they are not cheap ones. Good patchbays from a good company like Audio Accessories are going to pretty expensive. They are not to be confused with Switchcraft or ADC bays. Their long frame patch cords (not the same as 1//4" TRS) are probably more than $25 each.
Actually, some of the Audio Accessories patchbays can not only be confused with ADC long frame patchbays but they are ADC long frame patchbays.  I fully agree with the sentiment regarding the difference in quality and reliability and that patchbays are not usually a good area to start cutting corners.
 
The same goes for snakes.  For one thing, I installations I would always suggest running more than what you initially need, be that more individual runs or a larger snake.  Installing a snake such that a problem with any single conductor could result in losing a channel and having to replace the entire snake in order to address that makes little sense.  I personally tend to avoid snakes or cable in general where there is little technical information (rating, pair and overall jacket material, type of shielding, impedance and capacitance data, etc.) provided.  And can someone p-lease tell me what "Audio frequency controlling cable" is, http://www.seismicaudiospeakers.com/16-Channel-XLR-Snake-Cable-15-feet-p/sarlx-16x15.htm, and why you would want it?
 
Oe limitation I have found with XLR patching is the lack of being able to have normalled connections, you have to physically make each patch to have any connectivity.  I typically use programmable or all normals out bays for line level patching so that a 'default' configuration can be created with normals and easily modified as desired, however I have yet to find a good way to accomplish that for microphone patching.
 
I personally have encountered very few installed system where the deire is to have all the connectivity at one single location.  It is much more common to distribute the connectivity using wall plates, floor boxes and/or stage boxes at multiple locations.  In fact, it is not that unusual in some situations to have greater physical connectivity than you have inputs to the mixer.  These factors can impact how to effectively wire the stage and may make a single, large snake impractical.
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TJ (Tom) Cornish

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Re: Patchbays
« Reply #11 on: July 26, 2011, 11:45:04 am »

Brad mentioned in an earlier post that the fire code rating of the cable (plenum/riser use, etc.) may affect what you can install - if you're going through walls or HVAC returns, it's unlikely you can just buy an off the shelf snake and drag it through.  Just wanted to re-highlight that point.
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Jacob Robinson

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Re: Patchbays
« Reply #12 on: July 26, 2011, 11:50:25 am »

if you're going through walls or HVAC returns, it's unlikely you can just buy an off the shelf snake and drag it through.  Just wanted to re-highlight that point.


So a snake like this:
 http://audiopile.net/products/Stagelink_snakes/PSPX-32-8/PSPX-32-8_cutsheet.shtml 
is not allowed to pass through walls and attics?  The space is not a plenum space.
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Ryan M. Fluharty

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Re: Patchbays
« Reply #13 on: July 26, 2011, 12:14:59 pm »

I personally tend to avoid snakes or cable in general where there is little technical information (rating, pair and overall jacket material, type of shielding, impedance and capacitance data, etc.) provided.  And can someone p-lease tell me what "Audio frequency controlling cable" is, http://www.seismicaudiospeakers.com/16-Channel-XLR-Snake-Cable-15-feet-p/sarlx-16x15.htm, and why you would want it?

It's amusing that one of their selling points is that the connectors are XLR and that's why its a "pro" solution.  I've never seen a stage snake without XLR connectors and suddenly the image came to mind of someone using 1/4" unbalanced Radio Shack microphones for an event with the apparent  "less quality" snakes that are out there.
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TJ (Tom) Cornish

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Re: Patchbays
« Reply #14 on: July 26, 2011, 12:34:28 pm »

if you're going through walls or HVAC returns, it's unlikely you can just buy an off the shelf snake and drag it through.  Just wanted to re-highlight that point.


So a snake like this:
 http://audiopile.net/products/Stagelink_snakes/PSPX-32-8/PSPX-32-8_cutsheet.shtml 
is not allowed to pass through walls and attics?  The space is not a plenum space.
Ultimately that's up to your local fire marshall to decide.
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Brad Weber

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Re: Patchbays
« Reply #15 on: July 26, 2011, 04:04:44 pm »

So a snake like this:
 http://audiopile.net/products/Stagelink_snakes/PSPX-32-8/PSPX-32-8_cutsheet.shtml 
is not allowed to pass through walls and attics?  The space is not a plenum space.
Not to pick on that snake but according to the description it is made using EWI SMC cable, http://www.ewisound.com/pro/pro12_2.html and I see:
  • Pairs that are individually shielded but not individually jacketed.
  • Nothing indicating the pairs are twisted, much less the twist rate, which is a major factor in EMI noise resistance.
  • Nothing stating the nominal impedance or conductor-conductor/conductor-shield capacitance, etc.
  • No indication of the cable rating.
This may be perfectly good cable for many uses, there is simply no way to know from the information presented if it is a good choice or whether it can be run in walls, in risers between floors or in plenum spaces without being run in conduit.
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Jonathan Johnson

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Re: Patchbays
« Reply #16 on: July 27, 2011, 12:17:09 am »

Brad mentioned in an earlier post that the fire code rating of the cable (plenum/riser use, etc.) may affect what you can install - if you're going through walls or HVAC returns, it's unlikely you can just buy an off the shelf snake and drag it through.  Just wanted to re-highlight that point.

To expand on this point, penetrating fire barriers (certain walls, floors, celings) in a building typically requires special techniques, with approved firestop materials. Just blowing a hole in a wall with a hammer, running the wire through, then sealing it up with drywall mud doesn't always cut the mustard.

Even penetrating the removable tile in a false ceiling typically requires running the cable through a short length of conduit, appropriately sealed. The idea is to limit the amount of smoke and oxidizing & flammable gases drawn into or out of the plenum space during a fire. In this case, it's not so much a fire barrier as it is a smoke barrier.

The plans for your building may indicate the structural components that are designated fire barriers. The AHJ* may require this to be noted on your plans.

*AHJ: Authority Having Jurisdiction, typically a building inspector, fire marshal, electrical inspector, or other official.
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Re: Patchbays
« Reply #16 on: July 27, 2011, 12:17:09 am »


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