Optimising XMon Performance

This week I have been setting up our new Monitor Remote (Now called the TMC-1) on the XMon.  I have heard some bad reports about XMon so I wanted to be sure that I knew how to optimise the setup. 

XMon cannot be considered in isolation but as part of a monitor system that consists of the XMon, Power amps and Speakers.

The main gain section of XMon uses digital gain control to provide a gain range of +31dB to -95db.  As can be seen on the chart below to optimise the signal to noise it is important that XMon is run at between 0dB and +10dB gain for normal levels.

The Speaker trim section of the XMon provides a gain range of 0dB to -63.5dB in 0.5db steps. As can be seen in the chart below the signal to noise remains the same for the first 4dB of attenuation but then the noise floor levels out so that the signal to noise degrades as attenuation is increased.

The factory default settings of the TMC-1 XMon controller are as follows 

Main Gain Section +4dB gain.

Speaker Trim -4dB

Overall gain 0dB

Speaker trim range is restricted to +/- 4dB

Input makeup gain +20dB to -10dB

The default setting provides 5dB of analogue headroom above the digital clip point when set in this mode (XMon clips at approximately +25dBm).

New TFT Monitor Remote for XMon

I have now returned from IBC where we were showing our new TFT based remotes. The new TFT Monitor Remote generated some interest.

Designed originally as a remote for XMon CB plan to interface to other monitor systems including our own digital unit. There are 4 easily accessible main screens arranged in pairs and include: Input/output selection, Meters/Solo, Cue selection and gain, Talkback/Listen Gain.

This unit has the same profile as the PD-1 and sits conveniently on or may be sunk into a desk.

Using an embedded processor the unit communicates directly with XMon via Midi. and controls the full functionality of XMon.  No other computer is required. The remote is fitted with a talk-back microphone and headphone jack and uses the same 15 pin connector as XMon. A GPI port is provided for Hardware Mute, foot switch input and PFL/AFL switching.

The USB connector provides power and allows for software updates. The USB Midi connected to Protools or any MTC source can be used  for Auto-Talkback (or even a Timecode display).

The 4.3" TFT display is fitted with a touch screen in case required for the future, the XMon interface does not use touch.

For the future
we are designing a digital audio monitor system that will use the same remote, We are also looking at other applications using the same technology, one suggestion is as a digital microphone remote.

The photograph below is of the prototype unit and a selection of un-retouched displays.

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New TFT Remote Panel with LCD Keys for DFC Console

As promised in the last Blog here is the first picture of the new remote panel as suppled to Twickenham studios.

The main features of this panel are as follows

• TFT Display - able to display more system information.
• 21 programable keys - only the keyboard, Shift, Recall, Store are not programable.
• The lower 18 keys are LCD keys which display the key function.
• Jog Wheel, four LCD keys may be replaced by a Jog Wheel.
• Two Serial Ports and a USB serial port.
• Two or more panels may be connected in a daisy chain.
• Direct connection to CBServer via the USB port.
• Sony 9 pin Input for control from desk
• Software updates and keyboard programming via USB port.
• USB Powered  

Fully compatible with existing systems this panel is currently available as a remote to the RM-6 and existing systems as shown in the updated Twickenham block diagram (previous blog). Below is a system diagram using two DFC-TFT remotes and a RM-6.

Atmos, Twickenham and Multi-Machine Track Arming enhancements to the Sony Protocol

It took a few try's to get the system at Twickenham working properly with two 64 track recorders, but after 1 week it seems to be working well. As part of the installation I installed the prototype of our new TFT based remote control panels - see the next blog entry for a full description

If two 64 track recorders becomes normal then it will be necessary to reconfigure the communications between the console and the machines/machine control system. The DFC has 6 sony P2 ports that will support 48 tracks per port but a number of consoles only have one port.

The standard Sony protocol can only control one recorder, here are three possible solutions to track arming multiple machines from a single sony protocol port

1) Implement our xmc protocol,   a number of years ago Harrison implemented this which allows them to track arm multiple record machines. The advantages - no modification required to our systems and frame accurate timecode without video syncs, disadvantage - a major change to the console communications s/w.

2) Map the tracks over multiple ports, the maximum possible is 112 which can be mapped over multiple tracks. The advantage - no modification required to the controlling s/w, disadvantage absolute maximum number of tracks is 112, not all serial ports implement the maximum (eg. DFC 48 maximum),.

3) Enhance the Sony protocol to support multiple recorders. The advantage - can support up to 112 tracks per machine, disadvantage - The controlling s/w must be modified to support the new commands. Most of the required commands are present in the RM-6 to support the our multi-machine protocol (xmc) a subset of these can be added to the Sony protocol.

What are we doing about multiple record machines?

1) The next release of the RM-6 will include all the above solutions. Once implemented the commands will be available for any manufacture to use.

2) I am currently updating the serial control system for one mixer manufacture to increase the number of record channels to 96,  at the same time I will add the commands to support multiple record machines.

Recording up to 192 tracks on two Protools from a DFC

As noted in a earlier blog the DFC can only arm 48 tracks on each serial port, this two ports are required to arm up 96 tracks on a single machine. In order to record up to 96 tracks on two machines 4 ports are required!

The diagram below shows how this is done and the menu settings required to achieve this at Twickenham Studios.  Note that the menu entries are for the latest version of the X4 and RM- software which were updated this week. Contact me for further details if you need them

Diagram updated to include a second remote, our new DFC-TFT as requested by Twickenham.

Detective work in Paris

Some months ago Daniel (our French representative) complained that every morning his SR-4 crashed when turned on, when reset or restarted it worked without problem. My test unit in the UK however did not suffer from the same problem even with identical software and setup.

A visit to Paris found a bug reading the EEPROM that caused the unit to crash if it could not interface with the EEPROM there remained the problem of why it was not reading the EEPROM.

This week Daniel swapped the chip used to read and write to the EEPROM, this cured the problem, but even when the old chip was put back the problem was gone!

The moral of this story is that if you are having strange problems on old equipment (the SR-4 4 was probably 15 years old) try removing any IC's on sockets and cleaning them!  

Advance Information on a new remote for the RM-6

Bellow is the TFT-422 the first in a new series of remotes that we are developing this year, This uses a TFT Display, with combination of  LCD keys and normal keys.

In developing a new remote for the RM-6 we have added two features to our remote controls, as follows

1) TFT display, our new interface can drive 3.5", 4.3" and 5" displays, the TFT display is the same as used on most smart phones and gives a bright clearly legible display capable of showing more information than the existing 2x40 LCD display.. One of the more obvious differences in designing a panel for LCD or TFT displays is the shape, this required changing the panel and the layout of the display. The display on the above panel is a 3.5" TFT.

2) LCD Keys, allowing macros to be changed easily, allowing individual users to define there own key sets. In using LCD Keys you have to take in consideration that they are bigger and deeper that our standard switches  and cost 15x as much. Because this is a free standing unit it would be impossible to use LCD Switches at the front as they are too deep.

We are also planning a new built in panel with all LCD keys except for the Numeric keyboard with an option of extra keys or Jog Wheel