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Thread Patchbay Issue :(

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  • 2 participants
1 Patchbay Issue :(
Guys, I have an issue !!!
Well, its about my patch bay and the effect units connected to the mixer via aux send and return.
To ease my explanation I’ll use this as a shortcut.
Patchbay Top row :TR
Patchbay Bottom Row: BR
Aux Send: AS
Aux return: AR
(BTW the mixer is: Behringer 2442FX and my patch bay is behringer PX3000)
Well. The configuration is
AS1: TR1 AR1: BR1
AS2: TR2 AR2: BR2
AS3: TR3 AR3: BR3
AS4: TR4 AR4: BR4
DBX 386 CH1 OUT: TR5
DBX 386 CH1 IN: BR5
DBX 386 CH2 OUT: TR6
DBX 386 CH2 IN: BR6
Alesis 3632 CH1 OUT: TR7
Alesis 3632 CH1 IN: BR7
Alesis 3632 CH2 OUT: TR8
Alesis 3632 CH2 IN: BR8
*Alesis Quadraverb CH1 + CH2 OUT: TR9
*Alesis Quadraverb CH1 + CH2IN: BR9
*Lexicon MX300 CH1 + CH2 OUT: TR10
*Lexicon MX300 CH1 + CH2 IN: BR10
*Behringer REV2496 CH1 + CH2 OUT: TR 11
*Behringer REV2496 CH1 + CH2 IN: BR 11
Behringer MDX1600 CH1 OUT: TR12
Behringer MDX1600 CH1 IN: BR12
Behringer MDX1600 CH2 OUT: TR13
Behringer MDX1600 CH2 IN: BR13
Behringer T1952 CH1 OUT: TR14
Behringer T1952 CH1 IN: BR14
Behringer T1952 CH2 OUT: TR15
Behringer T1952 CH2 IN: BR15
Behringer T1951 CH1 OUT: TR16
Behringer T1951 CH1 IN: BR16
Behringer T1951 CH2 OUT: TR17
Behringer T1951 CH2 IN: BR17
Behringer FBQ3102 CH1 OUT: TR18
Behringer FBQ3102 CH1 IN: BR18
Behringer FBQ 3102 CH2 OUT: TR19
Behringer FBQ3102 CH2 IN: BR19

Well, to be clear. The cable im using in the mixer return (since its stereo) is TR insert cable. I read that insert cable can be used as a stereo cable. by Connecting Red cable to Right Aux Return, and Black to Left Aux Return. And I am using it for the the 4 aux return channels. *And the same thing is used to all the effect racks ins and outs (QUADRAVERB, MX300, REV2496)
And all the other jack cables im using are TRS/Balanced Cables (Aux sends, all the other racks)
- My problem is, that with reverb I always get a disturbing fold/feedback decay-distortion sound. And I tried to do many solutions but nothing seems to work…
- Also, what is the modes I should use?? (Normalized, Half-Normalized, Thru)
- I would really appreciate it if you gentlemen have any suggestions in how to get the best out of my setup
- And the precautions to take in consideration will be helpful too.

Thank you  and excuse my English im not from a native speaking country.
Regards 
While setting up a pathbay / patch field there are a view terms you need to know :

  • Top row rear : input
  • Bottom row rear : output
  • Top row front : output
  • Bottom row front : input

  • Normal : Input and output are linked together inside until a jack is inserted in both input and output
  • Half Normal : Input and output are linked together inside until a jack is inserted into the front input.
  • Open : Input and output are always disconnected ( used for special setups - example : splitters )

CABLES both patch and link cables
  • mono jacks (TS : tip sleeve ) - used for unbalanced connections
  • stereo jacks ( TRS : tip ring sleeve ) - used for balanced connections
  • y-cables or insert cables ( TRS < 2x TS ) - used for combined insert point on some / most mixers

Balanced / Unbalanced
  • Unbalanced - 2 terminals ( 1 HOT , 1 SHIELD ) : signal travels over the hot line and returns over the shield
  • Balanced - 3 terminals ( 1 HOT, 1 COLD , 1 SHIELD ) : signal travels over both hot and cold lines ( HOT = positive , COLD = negative )

Patchbay or patch field :
  • patchbay : one unit with 48 terminals or more
  • patchfield : a complete setup with patch bays

Note : if people like to add some info , please do ... :D

How to setup a patchbay / patchfield ?
The best way is to set it up in a way that you have as little patch cables on the front when you work.
That is why most people use " half normal " the rear input and output are connected to each other without a patch cable.

but first we have to check what for output your mixer has. These days almost everything is balanced but sometimes on older mixers the AUX outputs are unbalanced.
In this example we are going to act like every port on the mixer is balanced
here we go :

we insert a TRS cable into the aux port 1 of the mixer and link it with the patch bay on the back top row 1
and repeat this with all the other aux ports ( aux 2 .....x to patch bay back top row 2..... x ).
next we connect the revel unit to the patch bay . this is done by inserting the TRS cables into the back bottom row 1 and 2 ( stereo )

Due the fact we have used " half norm " the reverb unit is linked to the aux 1 ( LEFT ) and aux 2 ( RIGHT ) and thus we can send audio to the reverb unit by turning aux 1 and aux 2.

The processed sound is getting back to the patch bay back port 3 and 4 .
you like to receive your sound on the mixer at the stereo return , so link this port to the patch bay rear bottom row 3 and 4.
these are also liked due the half norm so you will not use any cables for the front.

so the sound patch is as followed :

aux send 1 ---> patchbay rear top row 1 --->
HALF NORMAL sends signal back to the rear bottom row 1 --->
reverb unit Input Left ---->
DSP processor sends signal to output left / right and and thus to the patch bay rear top row 3 and 4 --->
HALF NORMAL sends signal back to rear bottom row 3 and 4 ------>
Signal received by the mixer on the stereo return left channel ( patchbay 3 ) and right channel ( patch bay 4 )

as you can see i only use TRS cables and no insert cables .....and i have to dubble everything if i want to patch stereo signals

Why ?

because we said earlier that the mixer had balanced outputs and thus the signal on the patch bay is also balanced.
If we inserted a insert cable into the patchbay the balanced signal is being split up meaning :

on the TS side of the insert cable we now have a signal [ positive / sleeve ] and on the other end we have [ negative / sleeve ]
if these signals are mixed at the wrong place inside the mixer or effect board you will end up with no signal , very low signal or even distorted. However if the signals are mixed correctly you will end up with a difference between left and right and sounds a bit like the rear signal of the first dolby surround rear channels. If this signal is the difference of the reverb unit than you will end up with the difference of the reverb left and right... which may sound like a distorted semi delayed signal with a lot of digital artefacts.

I hope this cleared everything a bit up for you....
If you have questions, please ask them

- Angelie


When using a balanced port you use TRS cables ( stereo jack ----- stereo jack )
you can use TS cables ( mono jack ----- mono jack ) but you will lose some signal because you don't have the COLD line .....

on an unbalanced port you can use both TRS and TS cables ....

It's not about what you got to use ....    but how you use what you got...

[ Post last edited on 04/17/2015 at 11:48:44 ]

Thank you angelie, i'll try to re arrange my system accordingly. i may ask you again if i have further quistions about it. because truly it is hard to find some good post about it.

Thank you again angelie :)
No problem.

When home i will add an example of some kind of layout. With images.

So you can see how you can setup your patchbay. Remember to take some time to think things through...

- Angelie

It's not about what you got to use ....    but how you use what you got...

[ Post last edited on 04/21/2015 at 01:08:38 ]


As you can see on the image above the top row ( output ) is used by the scarlett18i20 and octopre outputs.
The bottom row ( input ) is used by the HILL ( mixing console ) . Due the use of " Half Normal " i don't need cables to link the audio interface outputs to the mixing console inputs.

The red cable on the input of HILL Remix 7 breaks the " Half Normal " . now the output go the Scarlett CH7 is no longer attached to the mixing consoles input. Due the red cable the input on the mixing console the mixer is now getting a signal from another source which came from another bay.

At the bottom of the image you can see the top row ( output ) being set as : SEND - OUT - SEND - OUT .... etc.
the bottom row ( input ) being set as : RETURN - IN - RETURN - IN etc....

on group of SEND,RETURN, IN and OUT belong to one piece of equipment , a compressor
Due the fact that this is one piece of equipment and the out and input may not be linked to each other this bay is set as : " OPEN "
" HALF NORMAL " would link the Input and output to each other and causes a feedback loop

I hope it is a bit clear now when to use " OPEN " and " HALF NORMAL "

- Angelie

It's not about what you got to use ....    but how you use what you got...

[ Post last edited on 04/22/2015 at 10:18:38 ]

Its is more clear than ever.
thanks alot angelie.

i'll try it out :) and i will contact you if i needed help in this matter :)