question about wiring setup and layout...please help!

Discussion in 'Microphones (live or studio)' started by separation, Nov 7, 2006.

  1. separation

    separation Guest

    Hey all.

    Got a question about my wiring setup and layout. I'm going to try and explain things as best as I can and give you a mental layout of my setup. Here is my room setup. I have a live room, control room, and another vocal room. I have snakes running from each of those rooms into my control room. For instance, I have an 8 channel and 16 channel snake running from the live room into the control room and another 8 channel snake running from the vocal room into the control room. Each snake has 4-TRS returns on them for my headphones.

    I have all these channels running currently into my A&H GL220 board and then I use the direct outputs of the board into my MOTU units and then use the outputs of the MOTU gear back into a Stereo channel on the A&H board to monitor.

    What I would like to do is have a central point to connect all of these snakes together so I can patch them into other external preamps such as my ISA-428, and my Octopre. I have great external preamps but I can't get them connected without digging through a mountain of cables and repatching things all over the place. I've known for some time now that my setup is MAJORLY flawed but I've gotten by up till now and its just time to fix this whole thing now while I have a chance.

    The problem is the connections. I haven't found a patchbay or OTHER CABLE SNAKE that could convert the XLR connections to TRS connections so I can patch them to my MOTU which is completely TRS and no XLR. This is especially difficult with my ISA-428 since it only has XLR ins and outs so I have to convert that to TRS to get it into my MOTU units. Is there an overall belief in signal loss by using patchbays and extra patchpoints? While I don't mind spending money on cleaning stuff up I don't want to spend a ton of money on these ideas either. I'm hoping for a happy medium that is still accurate!

    Could someone please send me some links or options, models, units, etc that will help me clean up this mess? From what I've researched the XLR to TRS patchbays are very expensive and ultra bulky but I've heard people talk about using other snakes that would take the XLR ends of my current snakes and bring them into TRS ends? Is there something out there that I haven't found yet?

    I thought that you had to use XLR transformer adapters to convert to a 1/4" TRS end? Is this not true? I've seen the cables with XLR on one side and 1/4" on the other yet from what I've read and experienced they have very poor characteristics.

    I'm sure there is a simple process for me but I would love to get some suggestions and help with this. I've got some nice gear but I would really like to clean up my signal path properly and don't mind spending money to make things better but don't want to waste it on the wrong things. Which I seem to do quite often!

    Thank you in advance, I really am at my wits end here...
  2. DIGIT

    DIGIT Guest

    >>I've known for some time now that my setup is MAJORLY flawed<<

    I don't know about that but, I would have used wall plates instead of snakes for sure.

    One thing you could do is setup a Patch bay that would allow you to connect the mics to whatever pres you have, as needed. There are plenty of ready-made TRS/XLR cables out there. You would then patch the microphones (however many or few) you usually would use onto the patch bay and then, patch them into the pre of your choice.

    Another way would be to patch the pres & MOTU & relevalnt Mixer channels ONLY to the patch bay and then, manually connect the mic cable(s) to the pres as needed.

    IN my studio I have wall plates; this allows me to connect the mics DIRECTLY to the pres, which I prefer. The pres OUTS are then sent to a patch bay, along with all my A/D/A converters' IN/OUT connections.

    Finally, I have the LINE INs of all the pres ALSO connected to the PatchBay.
  3. cusebassman

    cusebassman Active Member

    Sep 13, 2006
    Well, you can definitely get snakes that convert XLR connectors to 1/4" TRS, with no signal degradation (or no more degradation than any other addition of cable would cause). However, it depends on what you want to do. For example, if you are running XLR-based mics into a snake that you then want to run into a preamp, chances are the preamp has XLR connectors on it as well, so you could just buy an all-XLR based patchbay. However, if the XLR patchbays are too expensive, your preamp has TRS inputs and outputs, and you are then running the TRS outputs to the line-ins on your board, you could easily set up something like the following:

    Connect the male XLR plugs of the 16-ch snake to the female XLR ends of a couple of 8-channel TRS-to-XLR snakes, then connect the TRS connectors to the back, top row of a TRS patchbay. Then run the bottom back TRS plugs into your pre's, so that patchbay becomes a router for what channels of the 16-ch snake are going to what pre's. Then run the pres' TRS outputs to the top back row of another patchbay, and the bottom back row out to the mixer. This will give you the ability to route different inputs on the 16 channel snake to different preamps, and then run different preamps to different inputs on the board.

    This was very long and seemingly a bit confusing. If you would like more details, lemme know. Hope that helped!
  4. separation

    separation Guest

    Thanks for commenting. So your wall plates are just XLR wall plates and you connect your mic cables up to the wall? Then on the other side of the wall plate you connect another XLR cable directly to your PRES? Then out of the PRES via TRS and into a patchbay which you can then run into your system? Is this correct?

    I guess what I'm asking then is similar in design to what you had. I thought about going with the wall mounts but went away from them because of the sound leakage I was concerned with between the walls of the live room and control room. Currently there are only a couple of wall mounts running live monitor runs into the live room.

    Couple of questions!
    1. Do you know of another high quality cable snake that can convert my cables from XLR to 1/4" TRS??
    2. Do you know of a nice XLR to XLR patchbay that I could connect things up with? I've tried one in the past but the quality was pathetic and I really was disappointed with it. I'd like to have something Nuetrik or equivalent.

    thanks again.

  5. separation

    separation Guest

    Thanks, it helped immensely. However, the back of the ISA-428 and potentially in the future a Focusrite RED or Avalon preamp will only have XLR in's and outs. So while I can use the system you described for almost all my other preamps I'm still stuck on the other XLR inputs for the higher end preamps! Would this be something I could just get the XLR patchbay to use. Seems logical.

    Any thoughts on what types of patchbays I could use? I've checked with Markertek, MF, American Musical, Guitar Center, Sweetwater and most of them have about the same quality gear to the current Nuetrik NYS-SPP-L patchbays I have now. I'm really interested in finding the snakes you described possibly even in Canare or Mogami cabling. All my current Mic cables are Canare Starquad wire with gold plated Nuetrik ends so my cables are pretty good.

    if you have any suggestions or links to these patchbays or snakes please let me know. I would really appreciate it.

    thanks so much.

  6. natural

    natural Active Member

    Jul 21, 2006
    You can do all the above.
    Plus here's another option:
    1- Get a TT patch bay that either uses soldered connections or a punch block connection. (punch block uses a tool to impale the wire end onto a tiny spike)

    2-Now imagine this: Take your snake that runs from your room to the board. Now cut that snake at some point and connect all the bare ends to the patchbay in Step 1. (patchbays can be set up to be normaled which will pass the audio through to the console until something is patched in which will break the normal connection)

    3- Do all your snakes this way. You don't have to deal with different connectors. Patchbays can be wired to be balanced/unbalanced/grounded/ungrounded. Whatever the situation requires. you can make mults, invert polarity, etc. they're great.

    4- Coincedently I was thinking of putting a similar patchbay up for sale, which is setup as an insert patchbay. 40 TRS cables on one end that are used for a send/return loop, and connected to a 96 point TT Punchblock patchbay on the other end. Again, the cables can be disconnected and repunched to most any configuration.
    Contact me if you're interested.
  7. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    You're going to have a lot of fun with grounding, ground loops, phantom power and all the other goodies that go into creating a fixed based control room/studio operation. You're really getting into the realm of insurmountable problems.

    One of the first things you have to learn about running a studio is how to solder everything! That's an art like knitting a sweater is. You will get the hang of it after a few thousand of solder connections.

    I just love wiring patch bays. NOT!
    Ms. Remy Ann David
  8. separation

    separation Guest

    RemyRAD, so should I not go with a certain setup? I've had some ground loop problems before and they are frustrating to say the least. Nothing in my new building, at least at this point....knock on wood! I wondered what you might think of my setup as I really enjoy hearing your opinions about things. You have a lot of knowledge about the craft and getting information from you is always a bonus! If you have any direct suggestions I would really appreciate hearing your opinions. This forum is so amazing just in the amount of great information and dedicated people there are to their recording. I put this message up yesterday and have already got some great information both online and offline and I really appreciate all the help.

  9. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    You had inquired about the possibility of "XLR" patch Bays. Well, I have and NBC Washington has just that. In multiple areas of the studios reside XLR wall boxes with at least 6 inputs each around the studio. They terminate at the back of the room to another XLR panel which allows for a comprehensive XLR patching system to yet an additional XLR panel which is the input XLR tie line to the control rooms massive 1/4" Jack Bays. This gives us the ability to patch in anything in the studio. Route. To the desired input and then patch route to the consoles inputs where we want them.

    Very involved, quite cumbersome, great connectivity, great versatility. The one thing one must remember is that you will have phantom power going out your microphone snake and that you will also likely utilize back feeds from the control room to the box in the studio for headphone purposes. Some people indicate that they have feedback problems when running bidirectional audio information on a snake. But I have never had that problem since everybody has different grounding schemes. Mine just happened to work well, with the additional heavy-duty industrial isolated and balanced power transformer. That provides new clean power and eliminates any ground loops of my 250 foot microphone snake's.

    So basically, we created an XLR patching system as if it were 1/4" plugs and jacks that terminate in the control room into 1/4" jack panels.

    You have to make sure that the XLR pin 1 ground, is not connected to the Jack's case, which would make a common ground to all of the sockets. You want isolated grounds from each XLR Jack that have no common ground between each XLR Jack. Common tied together grounds can wreak havoc with ground loops, you're grounding scheme and phantom power supplies. So it may be important to lift some grounds that are inputting to your equipment? This may be audio grounds or the center pin electrical ground on your Edison connector? Being able to patch microphones into desired inputs is quite nice but the phantom and grounding dilemmas can cause you to lose sleep.

    If there are any other questions you would like to ask, don't hesitate as I know you won't.
    Ms. Remy Ann David
  10. separation

    separation Guest

    thanks so much!! I hope that if I ask too many ridiculous questions or plain dumb thoughts that you will just tell me to shut it up :wink: Do you have any pictures of your setup or what you described? I would love to see this. My brother actually lives in the D.C. area in McLean, Va and works for "Visual Aid Electronics" or "VAE". Not sure if its a good company but he seems to like it pretty well. Lots of hotel work and conference room setups I believe. Do you work for NBC Washington or just know of their system? Sounds amazing! I'm going to look further into what you mentioned as I have come across a nice Switchcraft Q-G Patchbay Series that might work well. Do you have any suggestions for rackmounted patchbays or conversion snakes?

    While I'm no professional at soldering my brother and I actually made all our Canare Starquad cables for the studio. It was the only way to get nice cables without robbing a bank. While it was only about 100 cables it was still a lot of work. Its been a while since we did those so hopefully I still remember. Its like riding a bike, right :lol:

    thanks for the help!

  11. zachzaba

    zachzaba Guest

    a little late on this one

    Hello, my name is Zach and I was reading some of your forums that were helping out a guy with a snake and a patchbay. I did read thru it to find some specific info but did not have any luck. The thing that confusing me is that I thought I was certain 1/4" and XLR have different impedances as well as the obvious different connector.

    I was going XLR in to a patchbay and out 1/4" to go thru a preamp (because the XLR ins on that are busted). If I used bus ground (I think is what its called) and which pin would I drop to go to 1/4". I'm guessing I would just take the non-inverted signal and ground...on the same scenerio (out of curiosity) the same thing would be done for a XLR going into a 1/4" patchbay. I have tried these scenerios but each one has a different bad effect...nothing that fits in a pattern.

    Thank you very much for your time.
  12. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    Hello zachzaba and separation! Thanks for joining in here.

    While I'm not an actual electrical engineer, the issue of impedance versus connectors is not as much of a concern, IMHO, for analog as it is for digital AES style systems. In that respect, when I was at NBC, the ability to patch microphones in the control room via the 1/4" TRS patch panels was a huge convenience. Albeit with the patch cords, which were brass, when they tarnished, this would caused huge connectivity problems. When that happened, you were treated to the lovely sound of explosions if phantom power was interrupted by intermittent connectivity. This did happen on occasion. It wasn't pretty and a good reason for not putting microphones on patch bays and/or keeping your patch cords beautifully polished, unless you have a specific reason for doing so. Having my remote truck, this patchability has been very helpful as it was for me at NBC. And the console's inputs, that I have, old Vintage Neve, are equally capable of handling microphone through line level input levels, on the same input. This can't necessarily be said for other consoles but if you have switchable pads, it's usually possib but rarely desirable.

    Proper grounding schemes are equally important as only the microphone inputs carried the ground through to the front panel 1/4" connectors in the patch bays. The other patch points and line level inputs and outputs did not share a common ground with the front panel 1/4" patch connectors. We did not plug in other types of items that were not hardwired into the system, into the 1/4" patch bays as a project studio might encounter. I'm dealing with that issue right now in the control room of my facility, as folks want to patch in other outdoor gear they bring into the patch bay. Unfortunately, everything is not balanced and requires an active ground connection. My grounding scheme does not include 1/4" thick copper bus bar throughout the control room like NBC had. Another reason why my API 3124m's still come in handy in a control room with a vintage Neve. Their 1/4" front panel inputs work out great since the API's have both XLR and 1/4" balanced TRS outputs. But things don't always work out that way and so ground loop can be a big problem.

    Sorry I don't have any close-up photos of the patch system I have in use. It's sort of the like showing you the grill of my car and telling you to envision the radiator behind it. Right, it wouldn't be of much help.

    The rarely helpful
    Ms. Remy Ann David
  13. Boswell

    Boswell Moderator Distinguished Member

    Apr 19, 2006
    Home Page:
    Re: a little late on this one

    I think what may be confusing you is the usage to which the connectors are put. There is no impedance difference (at least at audio frequencies) between 1/4" TRS and XLR connectors as bits of hardware. The convention is that XLR inputs on preamps, mixers etc are low-impedance microphone inputs and that 1/4" jacks are either medium-impedance line-level inputs or high-impedance ("instrument") inputs. This is only a convention; there is nothing inherent about the connector that dictates this, with the possible exception that phantom power can be present on XLR connector inputs without the likelihood of it being shorted to ground as the mating connector is inserted or removed.

    Yes, it will vary with the equipment being connected. It sounds as though you are talking about an unbalanced patchbay using TS jacks, where the signal is on the tip of the jack and the return is via the ground on the sleeve. These do not in general work well with balanced equipment fitted with either TRS (balanced) jacks or XLRs. There have been numerous threads on this subject (e.g. (Dead Link Removed), so I suggest that as well as doing a bit of searching, you make a table of the input and output configurations (transformer, active balanced etc) of all the gear you want to be connected to your patchbay. Much of the balanced gear will work (with a 6dB drop in level) by just taking the +ve signal and ground, but transformer-isolated inputs and outputs will need the -ve signal grounded for the +ve input to work correctly (no level drop in this case).
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