Manley Langevin HP-100 More-Me Headphone Mixer 2/1995 - 6/ 1996 D-SUB - Manual (Page 4)

To access the communication features the studio must use the 25 way "D" connectors because that
is where the TALK-BACK signals are. The multi-cable connecting to each station should be 12 pair
balanced lines with each pair shielded. 8 of these pairs are used for the 8 inputs. 1 is used for the TALK-
BACK signal from the control room and 1 is used for a DC voltage that tells the station(s) to use the
TALK-BACK signal. This DC signal can tell the stations to replace the music with the TB or to use the TB
in the headphone mix.. The DC signal can also be used in advanced installations to allow the producer to
talk to one station only. It also allows footswitch "TALK" and the possibility of a lit LED corresponding to
the station when a musicial pushes "TALK".
The minimum wiring requirements to use the TB input is 1 shared audio line with the TB signal
on it and 1 line shared for the DC signal. The TB signal is the producer or console mic signal amplified up
to line level. If a push button switch is wired to simply short the two wires of the DC line all stations will
hear the producer in the music. A more interesting way to do it is have two buttons - one for "TALK" (with
musc) - one for "INTERUPT" (kills the music and replaces it with the producer mic only). Here one of the
DC wires is switched to a negative voltage or switched to a positive voltage. This gives either "TALK" or
"INTERUPT" to all stations.
The easiest way to hear the musicians is to set up a "Room" or "Ambiance" mic. Another way to
hear the musicians when they press "TALK" is to monitor the shared TB signal. This line is shared
between the producer mic and all the stations so be aware that unless the control room monitors are quiet
you will likely get feedback when the producer talks. We do not recommend using this method unless the
control room is monitoring with headphones. There are better methods and we will get to them soon.
Let us suggest the idea of "D" connector Cue panels with 1 "D" connector per station. With a little
effort all of the features of these stations become available. We can have each of the stations mic outputs
appear at the patchbay. These are unswitched so that they could be used so that the musician does not have
to hit the button to be heard or for other tricks like ambience mics. The former is handy because most
musicians hands are full and/or busy much of the time. The control room still is likely switching these mics
but this is normal practice. With these individual "D" panels the control room can monitor exactly what
musicians have mixed for themselves. All it requires is more patchbay points and more wire. Then we
should have some logic circuits so that all this TB and monitoring is switched in when we need it and not
just points at a patch bay.
At this point we should notice that the the wiring and panels are getting ambitious. Langevin will
be introducing a few accessories to help fulfill the promise of the system. The first would be a that "D"
panel in the studio with a few tricks to reduce the wiring demands. One idea is to select the station monitor
lines and mic lines at the panel. Another idea is to mix those mic lines across a stereo pair so that it is
possible to hear everybody at once. That reduces the number of audio lines running from room to room.
We could supply one or two panels with 4 "D" connectors and a few extra outputs for those
Studio Loud Speakers (SLS). One panel would need a 12 pair cable and a logic wire thru the walls. Two
panels would require a another logic line maybe. We would connect one panel to the other with a 12 pair
cable plus that logic line. A bit easier.
Back at the console another Langevin accessory would be a small box with several
communication buttons and a mic. The bigger buttons are labelled "TALK", "INTERUPT" and "LISTEN".
Two rows of smaller buttons are labelled "1","2","3","4" and SLS. Next to the small buttons there would
be two switches - TALK/INT and MIC/ MON. Pressing "TALK" allows the control room to talk with the
music, INT kills the music but not the mic. "LISTEN" causes a relay to switch from the normal monitor
source to the selected new source. This new source is selected by the MIC/ MON switch and the buttons 1-
4 or SLS. If MIC then you can listen to any of the stations built in mics or all of em' in SLS. When a
musician presses "TALK" at their station automatically LISTEN + MIC light and a LED corresponding to
that station lights up. In other words you hear him or her. That other row of 1-4 + SLS is to talk to
individual stations. That switch marked TALK/INT is to choose how you want to address them. This box is
connected to the panels with a modest cable. Do you want 1 or 2 of these console boxes? 2 would give
access to everything in an 8 station system however, in reality, it is unlikely that you really require
"everything". A better reason for a commercial studio to have two boxes is that the producer and engineer