If you don't wish to use a Behringer mixer like the X32 and want something
similar in the same price range, the Allen & Heath Qu series is very
similar. The USB interface is reported to just show up in ALSA[1] and
while the remote control stuff does not come with Linux support, All the
remote control stuff is midi and completely documented. (I have waded
through it) There have been Android remote control applets written for it
(well the QU16 which has been around the longest) and it understands
rtpmidi it seems.
Despite some of the reports that the internal effects (channel
strip/insert effects) can not be inlined with the USB IF, looking closely
at the manual seems to indicate that these people have used the default
settings and there are other settings that would allow the "direct out"
to be selected from more than one place in the channel strip (post pre,
post insert, post eq, post compressor and post delay). While there is no
post fade, the direct out has both a trim level and the ability for the
level to "follow" fade and/or mute. Direct out placement selection is
global. Of course all of these settings are not in the same place :P The
Direct out source is on the Channel routing screen, while the
Insert/directout selection is on the USB audio screen... and the default
point for the direct out would make it behave just like the Insert
selection. I do not know what latency this would add to a track, but the
DAW should be able to compensate for that anyway. At the least, the talent
would be able to have a live/effected monitor of themself and other
tracks.
On the plus side for the Qu mixers, up to 18 sources can be recorded
direct to USB disk (this same limit of 18 is there even on the Qu32 which
can send 32 sources to USB AI). This means that carting a computer along
to a gig to record is not needed if you would be using the unit both for
recording and on the road. This can be used for preliminary sound checks
of all channels/monitors with no band in place. (The X32 can only record 2
tracks to USB disk BTW) The 18 WAV files could then be imported into one's
favourite DAW from USB drive for mixdown if desired.
There are scene memories so having a setup for recording as well as
performing (more than one venue) is possible.
In all my searching I have not seen complaints about the A & H line of
products in terms of reliability or audio "funnyness". The i/o do not
have transformers (not in this price range) so grounding needs the same
care as always.
The big difference from the X32 series to the QU is that the smaller X32
like the Producer with 16mic pre can control up to the same 40 inputs as
the full X32. The Qu series mixers will only control the number of
channels they have connectors for. These i/o can be replaced by digital
snake i/o if desired. This shows in the channel strip layout on the two
boxes. The X32 channel strips are broken into two sections with one for
input strips and one for bus strips. So the input strips can only be seen
in banked/layered mode. The Qu series has a strip per input with a layer
switch to see the bus strips, both have a master strip as well. The Qu
also has a custom layer to set as the user wishes. There is enough info in
the MIDI spec to set up a MIDI map for use with a DAW (Ardour for
certain).
[1]
http://community.allen-heath.com/forums/topic/ardour-linux-qu32-usb-recordi…http://ubuntuforums.org/archive/index.php/t-2262870.html
--
Len Ovens
www.ovenwerks.net
Fader mapping in general has been tied to the phyisical fader and it's
length. 4in/100mm seems to be the max real estate people want to use. Ok
so far. The mapping is set up to use that 4in in the best way possible,
but seems to be the same no matter what the use. There are three main uses
I can see:
Broadcast - Fades to oo(off) happen often
Live Mix - Fades might happen once in a performance (maybe 2 or 3)
recording - Fades are more often done with some kind of automation
maybe never on a physical fader... or maybe only
on bus faders.
Assuming a recording/mixdown situation, would it make sense on a limitless
fader to continue at the same db drop per movement from +6(or 10 or
whatever) to -110?
My reasoning is this:
By recording, I mean DAW and so 32bit float derived from 24bitADC.
Tracks are therefor recorded with more headroom and less compression as
these can be dealt with later. DAWs do not seem to think in terms of a
channel strip trim at input so that each track can put the fader in it's
most acurate possition (right around 0db) and something loud that is
really background may end up with it's fader position quite low. This
would mean minor adjustment to that track would be difficult. Would it
make sense to be able to move the range of a fader (physical or other
wise) so that it goes from -10 to oo rather than from +10 to oo? Think put
one finger on a modifier key and then move the fader from where the signal
is to where on the fader strip you want it then release modifier key. SO
if the fader is at -20 and this was done, -20 would now be at the 0db
possition.
Or if using a mouse wheel, the same amount of wheel clicks would move the
same db at any place on the fader... or a new type of fader might make
this possible too.
The thing is, a fader is no longer an audio pad that can be adjusted, it
is a data input device and as such it just has a linear position output.
There is no reason that data and it's meaning can't change on the fly as
needed. For most mixing (even live) the fader input is either "I need more
of that" or "I need less of that". In such a case, the sound the engineer
hears is what they go by, not the fader position. If the fader position
has to be looked at to change it takes the engineer's mind away from the
mix momentarily rather than if the operation position is always the same.
I am thinking what would work for a blind person, and wouldn't that be
better even for someone with sight?
With the talk about the X-air etc. not too long ago, I have played around
with the remote (PC and Adroid) mixer apps and the faders work in such a
way that touching (clicking) on any part of the fader and moving will take
the current value and mov it in the direction the finger/mouse is moved
(Ardour3/4 and maybe 2) are the same. In my opinion this is the right way.
Most touch surfaces either require the finger to touch where the control
is right now before it will move (second best) or will jump to where the
finger hits... bad or the worst ones are ones where the fader does not
move till your finger gets to the control, but moves as soon as the finger
touches any part of the control which means that a finger moving from
bottom to top has the fader position jump down so the middle of the fader
control is at the finger as soon as the finger gets to the bottom of the
fader control and then start moving up. (just plain broken)
Actually, fading to oo would still be possible on the solutions I have
mentioned so far. Seems win/win. Another softkey could be used for reset
modifier.
Another solution might be to use a modifier key to make the fader set a
channel trim. This could be a good solution too or even as well. I would
think once someone has set up their channel strip with things like
compression (or anything level dependant) they would not want change the
input level though.
I am working on a control surface where the brain is a small Linux box. I
have been looking at different well known protocols like MCP and HUI as
well as what some of the digital mixers use (the ones that are open about
it). I am thinking about how I would want to control a DAW if I have
control of what I am doing.
I am interesting in ways that a remote application either via MIDI or OSC
can find out what plugins a channels has in it and therefore what are it's
controls I can play with. I would like to have an Android app that shows
the current channel (as selected by the control surface) strip plugins as
a set of tabbed pages with each tab showing a control GUI for that
plugin. (wifi based of course) The way Allen & Heath have done it for
their digital mixers is nice, but for a DAW where each channel may be
different and there may be more than 4 plugins, it is probably not the
right solution... the GLD is close though.
--
Len Ovens
www.ovenwerks.net
>
> Date: Tue, 31 Mar 2015 09:39:01 -0600
> From: Studio Channing <studiochanning(a)yahoo.com>
> Subject: [LAU] multichannel interface recommendations?
> Message-ID: <551ABF95.2040606(a)yahoo.com>
>
> we are searching for a new audio interface for a project studio and
> interested in the experiences others have had
>
> requirements are:
> * 8 (or more) channels simultaneous recording to computer
> * at least 4 preamps for mic level inputs
> * USB2 preferable to Fireware, but..
> * 100% linux compatible, ideally with a stock kernel
> * under $500 USD if possible
>
> less important is real-time monitoring functionality - this will mostly
> be used for bands playing live
> ...
> anybody have any recommendations
I have been looking for a similar device, 4 mic inputs to record a string
quartet, and bought a Focusrite Scarlett 18i8. I haven't used it for
recording yet but I did plug it into my Fedora 21 mini computer, started
qjackctl and all the inputs and outputs were exposed. It has 4 front panel
mic inputs, 2 can be switched* to line, 48v phantom on each pair, 4 TRS
balanced inputs in the back, S/PDIF in and out, and ADAT optical in for an
additional 8 channels in, 2 balanced channels out on the back with 2 stereo
(headphone) outs on the front, plus midi in and out. It lists at $400 at
several online retailers, I bought mine used on ebay.
There is an windows and mac mixer app, and you need to use the app to
switch the two channels from mic/line to instrument and change other
configurations. Focusrite states that they don't guarantee Linux
compatibility but they have published enough interface information that at
least two programmers have created Scarlett Mixer python apps on Github,
one is by Linux audio guru Robin Gareus. With the program you can assign
the headphone output as zero latency input monitoring or as output from
your computer.
http://us.focusrite.com/usb-audio-interfaces/scarlett-18i8https://github.com/x42/scarlettmixerhttps://github.com/trrichard/ScarlettMixer
It seems to have solid stage worthy construction and a power supply with
US, UK and Euro plugs.
-- Jeff Sandys
I understand my answer doesn't fully apply to your request but, if of
any interest to you, I'm currently happily using a Mackie 820i mixer,
connected via firewire with jack and ffado.
It has only 3 mic inputs, alas.
It features 8 inputs and 2 outputs.
The use of firewire and tape outputs might result not immediate, or at
least it didn't to me, but can be arranged to supersede some input
channels or mix in the "control room" via some routing buttons but
loosing volume control.
If you can afford it I might suggest a wider 1220i.
Best regards
Fabrizio
I have an external USB hub with its own power supply. It introduces a hum when I have its PS connected.
David W. Jones
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com
On Mar 30, 2015 1:00 PM, Len Ovens <len(a)ovenwerks.net> wrote:
>
> On Mon, 30 Mar 2015, Fons Adriaensen wrote:
>
> > Some week ago I had some spare time and decided to have a look at
> > it. Connected the USB to my Linux workstation and connected some
> > headphones to the mixer. Result: with all faders down and just
> > the HP volume turned up there was a high level 50/100 Hz in the
> > headphones. Removing the USB connection was enough to stop it.
>
> Good to know. The last mixer I bought I went through channel by channel
> and each control looking odd things like that. I would have thought there
> should be no analog Audio anywhere near the USB.
>
> --
> Len Ovens
> www.ovenwerks.net
>
> _______________________________________________
> Linux-audio-user mailing list
> Linux-audio-user(a)lists.linuxaudio.org
> http://lists.linuxaudio.org/listinfo/linux-audio-user
On Wed, April 1, 2015 2:03 am, Patrick Shirkey wrote:
> So you are saying that Behringer manufactured and released
> an entire range without testing *any* of them before they
> went out the door for ground loop issues at the board/design level?
Something much more limited and specific: I am saying that the
description provided by Fons of the behavior of that specific model of low
cost mixer is consistent with a "pin 1 problem" design flaw, although that
is a bit of a misnomer with a USB connector. "Pin 1 problem" is much
easier to say than "reference conductor common mode impedance noise
coupling" though. Possibly only affecting the headphone output, Fons
never mentioned whether he also checked the main or monitor outputs.
> Seem pretty unlikely even for cheap low end manufacturing from China.
Where the unit was manufactured has no bearing on where it was designed,
and there are examples of pin 1 problems even in expensive equipment.
With proper PCB layout noise from the computer chassis should not be a
problem. The problem and how to avoid it were popularized in the June
1995 Journal of the Audio Engineering Society, they devoted an entire
issue to grounding and shielding problems, and Jensen and Rane have also
spread the word through several white papers and tutorials. Many seminars
have been taught by Bill Whitlock of Jensen and Jim Brown of Audio Systems
Group consulting among others. This is not something esoteric.
> More likely this one just slipped through the (random) QC process
As Fons pointed out, the typical design style for that class of equipment
has all connectors soldered to a single PCB, and most of the assembly of
the PCB is performed by automated equipment. The balance of likelihood
between an assembly flaw that allows the equipment to work, but not work
fully properly, and a design flaw comes down on the side of design flaw
for this particular behavior. The solution is relatively straight
forward, but you have to fight against the easy way of doing things using
most PCB layout software, so it is commonly not done correctly.
> From his description it sounded like the device was working
> pretty good with Linux in every other way. Just a bit of
> hum at the hardware level.
Indeed, the improved standardization of USB interfaces has been very good
for linux audio. It would be interesting to see if the problem affected
every unit or was a manufacturing flaw as you speculated, and whether the
problem affects all the outputs or only the headphone amp.
Fons, did you happen to get the specific model number of that mixer?
--
Chris Caudle
