Topic: OMT rig snake

[EmRR]

Sometimes I run 2 channels, sometimes 3, sometimes more than 4.  Now that I'm moving towards 5 to 7 channel OMT rigs, I've ordered parts to put together (2) 4 channel snakes to keep wiring a little more sane. 

Looking at wire diameters I settled on Canare which I already like quite a lot. 

http://www.canare.com/ProductItemDisplay.aspx?productItemID=60

standard 1 channel is 0.236”/6mm
2 channel is 0.264”/6.7mm
4 channel is 0.299”/7.6mm
8 channel is 0.433”/11mm

My logic is while 8 channel would be the thinnest for 5 and up, it would frequently mean a lot of unused connectors hanging up a stand.  A 4 plus a 1 or 2 will still be pretty close to 3 singles in diameter. 

I grabbed Neutrik connectors with colored boots to differentiate channels. 

I'm considering making some sort of connector support bar for the snake at the top of the stand.  I usually run the short Rycote jumpers or similar from mic through shock mount clip to the longer wire run. 

I'll report back once I get it in use. 

Anyone have other experiences here? 

[Gutbucket]

Good idea in that the mass of cables is one of the bigger hassles in running multi-mic rigs.   Not only can the cabling end up weighing more than all the stuff aloft and endanger toppling a small footprint stand, its just a PITA to manage.

Dealing with with unused connectors and individual fan-out lines of sufficient length to reach your desired potential mic positions is the main issue I forsee. You might consider some kind of small conn box located at the top of the stand, into which you plug short patch cables of appropriate length to reach each mic you have in use.  That would insert an additional connection point in each mic line, but would streamline things aloft.  Could make a handful of short patch cables of various length as appropriate.  That would leave no unused cables with dangling connectors to deal with up there for channel counts of less than the total through the snake.  Might choose mini-xlrs in the conn box to keep size and weight down.

[Gutbucket]

My setups are unusual in this regard, yet may provide food for thought-

In my primary OMT rig I bundle individual small diameter cables together in techflex without permanently fixing the techflex at each end to provide a reasonable-diameter, fairly-flexible, coilable and otherwise-manageable 8-ch cable bundle from the recording bag up the stand to the microphones.  Because the techflex is not permanently fixed, I can re-adjust fan-out lengths as necessary or re-thread additional cables (such as the addition of the balanced cable pair when I added the center M/S configuration).  Once its all routed. I temporarily fix the Techflex at the mic bar end using gaff-tape and a cable-tie.  It remains unfixed at the recorder end which allows plenty of flex coil-ability as needed.  Once the stand is up and mics aloft, I can run my hand down the Texflex toward the recording bag to snug it up forming a tighter, stiffer, straight run down the stand without snagable bends or loops and it holds that state until I lower the stand and recoil it into the recording bag. This arrangement works really well.  It is easily manageable, reconfigurable, and allows me to adjust cable-lengths just right.  But it's intended for using the same setup each time, or slight variations on it, rather than reconfiguring for a different number of channels.  In working up to this arrangement I'd add or change cables through the techflex as I added or swapped microphones.

The cables I'm using are RG174-flexible coax with an outside diameter of just 0.10" / 2.54mm to 6 miniature DPAs (micro-dot connection located at each supercard, in-line microdot connection to the omnis) plus one of TS cable-maker Ted's small-diameter techflexed Teflon/silver balanced 2ch chopped RA XLR cables to the center M/S pair.  The DPA supercard Mid uses a DPA phantom adapter mounted aloft at the mic.  The Side 8 uses a balanced XLR connection.  The other 6 DPAs use Niant PFA phantom adapters at the other end, plugged directly into the recorder inputs.  When the Texflex is snugged-down the bundle is approximately the same diameter as my index finger.

Toughest part was adding the balanced cable pair for the M/S pair because the RA XLRs connectors would not fit through the Techflex with the 6 coax cables already in place, so I had to remove and re-solder them after threading that cable through. No problem running additional coax lines as they are microdot terminated on the mic end and mini-xlr terminated on the other to the PFA adapters, making either end small enough to be passed.

This arrangement is unusual in that I do not disconnect the cabling from the mics or the mics from the mounting bar when breaking down. I fold all the arms in and disconnect the mounting bar system from the top of the stand, coil the Techflexed cable-bundle and put the entire thing into a bag with the recorder (all mic connections remain connected).  I used to carry a separate bag for the mic/bar assembly which remained cabled to the recording bag, but I now use one bag for everything, except the tall stand.  A folding three leg foot and short telescopic extension fit into the bag, so if setting up on stage just above floor level or up to about 3' high, the single bag holds everything pre-wired and ready to power up and deploy.

Hope that's not too far off base and helps with ideas if nothing else.

[EmRR]

Thanks, that helps with some alternate visions.

Your setup is pretty unique and ingenious, I marvel that you made such a complete fold-and-go kit. 

Yeah, I really like the idea of using mini-XLR but I don't yet want to pay for 16 of them, plus dedicating 8 short jumpers to XLRF->TA3M. 

Your conn box thought is similar to the connector support bar thought I had.  Maybe with a hanger grip for additional strain relief. 

Going with two 4 channel feels like the best way to minimize unused connectors in the air, with changing channel counts.  A bonus byproduct is since I run a Zoom F8n, it's 4 inputs per side.

Lately I've been using reusable cable ties on a bundle of cables ahead of time to make (sort of) a custom count snake as needed, and then using more ties on the stand at top and bottom to lock the weight inline.  One place I can get a safety cable around the stand about 4 feet up, over to a support bracket at FOH, so one more thing to keep stand tipping less likely. 

Sidenote:  I checked with a company I work with occasionally, and they can knock out some custom rigging aircraft cable sets for me once I get measurements.  At one place I think I can get go-ahead to set up a flown mic bar from their balcony right above FOH, so could route wire up to balcony or down to FOH as suits. That feels like it might be safer for the rig, and would keep cabling further from random audience hands. 

[Gutbucket]

In place of cable ties at regular intervals you might consider a section of the split-side-entry type techflex or another side-entry cable-sleeve equivalent to form a temporary bundle.  Hoop tension of the split polyweave keeps the split closed.  Should work well even if the bundle consists of a single pair of snakes.  I imagine you could throw it on there at setup after the snakes or individual cables are run, and pull it off prior to breaking down.  I just have  never really liked the arrangement of ties every few feet, its snag-prone, doesn't coil well and never seems to lay flat.  Whenever I run extra channels in addition to what I have setup through the bundle I just use standard mic cables which I carry in coiled separately and velcro cable-tie them along with the existing bundle to the stand at a few points.

When I was changing things up alot, I considered a length of larger-diameter side-entry flexible fabric type cable sheathing that uses a velcro closure along the split instead of hoop tension to hold the split closed and retain the cables.  The idea being that the sheath would have a diameter sufficient to rap all the way around the vertical stand in addition to the cabling.  Length would be bit less than that of typical stand height down to the top of the stand legs.  I could then setup the mics however I wanted running individual cables or cable pairs, and put the cable rap on to secure the cabling in place from top to bottom as I raised the mics.  Reversing the procedure when breaking down.  That would be very flexible for changing things up and make for a slick streamlined stand with no free dangling bundle at all.  But the sheathing would need to be of sufficient diameter to go around the stand upright, the cables, and the stand's telescopic section securing knobs or latches.

In the implementation I'm using with a single non-side entry techflexed bundle and my recording bag either on the ground or floor beneath the stand or hanging from a stand knob near the bottom, I often need no additional cable ties along the stand except the one at the top, instead rotating the stand's telescopic sections so that the knobs securing each section in place act as cable retainers holding the bundle tight against the stand.

If you can determine the measurements accurately, that aircraft harness angle sounds sweet!

[heathen]

Gutbucket, do you ever clamp your rig to someone else's stand?  If so, are you able to do it without changing your whole cable arrangement and everything?

[Gutbucket]

I can more easily clamp it now, but most often other tapers clamp to my stand.  Previously it was more difficult to change from stand-mount to clamp-mount yet still doable .

I reworked it earlier this year so that there is a mounting stud protruding from the base of the center mic-bar hub where the cable bundle is attached.  That makes it easy to mount the array directly into a superclamp, to my tall stand (which has a female stud socket up there), to more typical stands using a threaded connector nut or rapid-adapter, to a telescoping arm, or directly into the 3-leg folding foot for on-floor/close-to-surface use (making the highest point less than a foot above whatever surface the foot is set on).   The short telescoping arm fits into either the folding foot or a superclamp.

Previously I had it semi-permanently rigged to a compact 6-7' Manfroto "nano" light stand (model number has changed over the years, but it's the small stand lots of tapers have used for decades where the legs fold up instead of down).  To change that to a clamp or taller stand I needed to take the top assembly apart holding the various arms together and securing the cable bundle, and reassemble that on a threaded stud that fit into the clamp.  But I rarely did that.

Instead, whenever I needed to go higher than ~7' I'd use a taller second stand and literally hang the pre-rigged small stand from the top stud of the larger stand, using a little tab incorporated into the center hub that had a hole through it which fit over the top stud of the tall stand.  That was a pretty cool arrangement.  I didn't need to drop the tall stand to add/remove the smaller one with the rig.  Instead I could extend the array, extend the telescopic sections of the small stand leaving the legs retracted, look up and hook the small stand over the top stud of the big one and securing it in place with a giant twist tie.  The two stands were more or less snugged tight together up with the small one in front and slightly to the side, so it wasn't overly visually occlusive.

Other folks could clamp to the big stand as long as they came off the back of the stand rather than the front, and I could remove my rig and run it to another stage or head back to camp or whatever without disturbing their rig or lowering the main stand.  Now I need to lower it to remove or add the rig, but its more streamlined and easy to mount on either the tall or short stand (or to the foot or clamp) as required.

[Gutbucket]

Current rig atop the tall stand with using stud connection (good view of previously described 8ch techflexed cable bundle, attached at top)-


As previously rigged on the small stand I'd used for years (same rig in slightly different geometric configuration, only using smaller windscreens indoors). Note that in this photo you can see the "hanging tab" with hole to fit over the stud of a tall stand protruding to the left from the center hub


In this photo you can see that I was using two standard mic cables in addition to the 6ch techflexed bundle for the newly added center M/S pair, prior to switching to the thinner Ted cable which runs through the techflex-


Previous OMT6 rig (no M/S pair, single rear-facing channel) semi-permanently rigged to small stand, with hanging tab visible -

[EmRR]

I just have  never really liked the arrangement of ties every few feet, its snag-prone, doesn't coil well and never seems to lay flat. 

Oh yeah, that's just what I've been doing and plan to move away from as fast as possible.

[EmRR]

Wire and connectors are in, the 4 channel wire is pretty much as easy to manage as the standard Canare single channel, nice and flexible with no apparent tendencies towards memory effect.  2 runs of that is smaller than 3 single channels of standard Canare single channel. 

http://www.canare.com/ProductItemDisplay.aspx?productItemID=60

[Gutbucket]

Good to hear.  I'll keep the 8-ch version in mind for future projects and maybe compare specs against Mogami's very small diameter multi-channel cable.  The TetraMic cable is made from Mogami (6 conductor I think), and is typical lav mic-wire diameter - super thin and flexible, but I suspect that comes along with cross-talk and capacitance.   I've not used it myself other than with the TetraMic, where it works fine.  Have you ever used any of the Mogami multicore stuff?   The super-small diameter stuff is categorized differently from their standard multichannel mic cable, originally intended for other applications.

[EmRR]

I haven't used the Mogami multi-core.  I use a lot of their install wire within electronics builds, that's the extent of my experience with their product. 

[Walstib62]

I've used the Mogami. 4 channel multicore at 150 ft with good results

[heathen]

I've used Mogami W2880, which is six conductor.  I've only used it to make one cable (for my Tetramic), I believe it's what CoreSound uses for their TetraMic cable.  It was easy enough to work with and seems sturdy enough for common sense use (I wouldn't put it where people are walking on it, for example), but I don't have the technical expertise to opine about crosstalk and that sort of thing.

[Gutbucket]

Used the stud connection direct to a superclamp to hang the inverted OMT8 rig from a ceiling beam last weekend. Really liking the flexibility of the stud connection which can be fit into a clamp, extension, or stand. At ~14' total length to the recorder, my permanent cable-snake was just long enough to make the short ~8' run back through the rafters and down to the front corner of the SBD by disconnecting at the recorder end to make the run.  Had to hang the recorder bag over the front corner of the board enclosure as the snake was not long enough to reach all the way down to a chair.  Worked nicely.

Thinking aloud here-
I'm now considering revising the OMT snake to include a single multi-pin disconnect for all 8 lines at both the mic end (adjacent to the stud) and at the recorder end, with short fan-outs to the mics and to the recorder inputs.  Would probably retain the individual cables within the snake and terminate to an multi pin Amphenol connector or something like that.  Something more robust and a better form factor than a D-sub connector.  We use Amphenols for connecting control-pendants on hydraulic boating equipment we build at work and they provide a robust connection.  Just need to keep the size (and weight) of of the disconnect at the aloft mic-hub/stud end small enough.

Such an arrangement would allow me to make two lengths of connecting snake, say 10' and maybe 25' or 30', which could be used in series if a longer run is necessary, or eliminated all together if the recorder can be placed very near the microphone-hub/stud-connection.  That last arrangement, along with a way of mourning the F8 and TallenCell battery might have been ideal last weekend, since I could have moved the array forward to the sweet spot which was a ceiling joist clamp-able location about 12' further toward the stage, yet would not make for an easy run back to the board.  I would then just start the recorder and just let it run in the rafters the entire show.   Once I confirm I have good signal across all channels and begin recording I'm not adjusting input gain anyway.