Channel EQ: Sub-Sonic Noise
The channel EQ in the d8b is known to generate a small amount of very low frequency noise when engaged. The different EQ modes (British High Pass, 20/20, etc.) produce different amounts of noise at different frequencies. The noise is cumulative so the more channels with the EQ engaged, the louder the noise, up to a certain point.
While it may accumulate to significant levels, it remains inaudible due to the fact that this
noise resides largely in the range below 10 HZ, increasing as it approaches DC, below the
capacity of the best sub woofers or the human ear.
A decrease in noise level by over 10 dB has been observed when a TC Finalizer high pass filter
was enabled at 5 Hz, between the d8b LR out and a DAW, via AES.
While inaudible in itself, sub-sonic noise can place considerable stress on power amplifiers and
speakers, overheating components and compromising audible frequencies.
For this reason, it is suggested that you apply a steep high pass filter (set between 5 and 40
Hz, depending on the music) to your mixes, either while recording the mix (as in the
configuration above), or in mastering.
Channel Filters: Static Noise
The Channel Filter “feature” on the d8b Channel List page does not work as intended, and should be disabled on every channel.
If not, you will hear a noise similar to static, and may experience very soft signals being
muted.
To disable the Channel Filters go to the Channel List under the Channel menu (the Control/B
shortcut does not always work). On the far right side, set every channel to Off. Best to save a
default start up mix after this, so you will not need to revisit the issue in the future.
The Channel Filter idea was to provide a noise gate before the A/D converters, that would
sense the noise level of connected equipment on boot up, and prevent noise from using the
least significant of the 24 bits available.
In spite of the good intentions, the idea never worked as intended, and when on, the Channel
Filter gates are subject to chattering and soft bursts of noise.
Flashing "Memory" Indicator
At the top of the VDU, to the right of the Menu section and to the left of the "Session" name indicator, is another little indicator that shows the "Memory" available for further data entry.
Sometimes, after long periods of heavy use and Automation procedures, the displayed number
can begin flashing between 0 and a higher number. It doesn't matter what that higher number
is.
If this happens, it is a sure sign that something is amiss and you should save your work
immediately, preferably with a suffix ammendment and re-boot.
Meter Overload Indicator Inaccuracies
The meters on the d8b indicate O/L (red) early. This was supposedly to help users by offering a margin for error.
The Channel O/Ls come on at -0.95 dBfs.
The L/R Master O/Ls come on at -0.58 dBfs.
0dBfs = Full scale digital = you don’t have no more headroom for those cowbell transients.
Note that all digital audio meters, hardware and software, use their own meter ballistics which are not standardized. Some show red lights as low as -4 or -5 dBfs. Others, at a certain number of samples reaching or approaching full scale. Some devices have user adjustable settings for this parameter.
Also note that there is really no such thing as an "Overload" (in the analog sense) at a digital
input, as the input cannot receive a signal greater than full scale (although there is certainly a
risk of overloading circuits before or after the input). Of course, the analog stage of an analog
to digital converter can be overloaded.
The "OL" indicators or red lights on digital inputs should be thought of as warnings, rather than
as a precise indicator of signal strength, loudness or distortion.
Video Monitor Refresh Rate for V5 and V5.1: Warning
Do not attempt to change the Video monitor Refresh Rate under “Windows
menu>Setup>Refresh Rate” if using O.S. V5 or V5.1.
This may incur a fatal crash that can only be rectified by a full format of your HD and
re-installation of the OS.
Mackie report:
Issue #40: Changing the refresh rate has no effect.
Workaround: None. Do not change the refresh rate.
Some users have reported problems, others have not. Whatever, to change it makes no
difference to the monitor’s appearance so it’s best left alone.
If you have not kept back-ups of all mixes etc. and this problem occurs, you will lose all of
your data.
It would be advantageous to grab a copy of the known issues regarding V5.1 OS by
downloading this PDF file so that you are fully up to speed with any anomolies.
Hidden Channel Strip Control Surface Functions
Press and hold the Channel Select button for a few seconds and the Fat Channel fluoro display will come alive with the following parameters for the selected channel that can be controlled from the desk surface:
- Group Assign
- Playback Mode (Run/Punch Run/Disabled)
- Write/Safe
- Channel Delay
- Plug Pre
- Plug Post
- Pre Patch
- Key Insert
- Phase Flip