CQ20B crash on USB multitrack playing

[jjm35]

Hello,
Yesterday was my firs gig using CQ20B mixer. My setup is: Ipad Pro with IOS 18.1 conected thru USB playing 5 tracks live with “Multitracker” App, 3 mics, bass and guitar (both with digital pedalboards). Two times in the gig I get frozen the audio in the Ipad, and a loud beep in the PA (two years using it without any problem on a Behringer X32, so no problen on the Ipad/app). The mics, guitar and bass still wassounding, but i have need to quickly restart the mixer to get off the noise. I suspect that the problem was only in the USB driver, and muting the channels affected would quit the annoing noise, but I was harry to get away that noise and simply unplug the power cord and plug it again in 5 seconds. Then all was ok for 30 minutes, and again the same problem.
I am a little scared about that, because it is not aceptable in my gigs and have to be secure to never happen again. Some ideas?
Thank you

[Hugh]

I have a 20+ year history of deploying A&H Consoles for both live SR and studio front end capture. The primary reason I left my Mackie gear and bought an A&H analog 24 track console 20 years ago was for dependable high quality transparent audio capture. I have owned and lived with three different digital protocols: QU, SQ & CQ. All three share a USB recording protocol that is clunky at best: however the CQ has a new unique SD card option that is far surperior to the ubiquitous A&H USB system.
Exactly 50 years ago I was up to my ears with production rehearsals for “Rounder 044-“The Old Home Place” project. Part of my managerial resopnsibilities was running the Live SR at all of their apearances on the road. I was at the mercy of high dollar commercial studios to provide the analog recording gear needed to deliver suitable studio recordings. A lot could be said, both pro & con, about the old analog Tubes, Tape and Ribbon days but for me the digital revolution has been a gift from above. My decision to open my own Project Studio 25 years ago was facilitated by the fact that pro level gear had then become available and afordable and fortunately I had accuired the production chops working with the commercial studios over the previous 25 years. This is what I know to be true;

1) A&H builds gear designed to deliver pristine live SR and offers ancillary recording options for capturing the said live performances.
2) Any of the better DAW protocols are much much better tools to manage Post production & two mixing than any live desk.
3) There is no better front end recording capture than a waves card delivering pure detailed A&H “Prime pe-amp” tracks, via tie lines, to your DAW of choice. Then you dial up the needed buffer settings, to accommodate CPU hungry Reverb plug-ins, with out any of the latency concerns we have to deal with in live SR.
4) The CQ SD card option is an entry level multitrack recording protocol that can provide dependable, transferable tracks to your DAW for post production processing: not the best quality but far better than most.
Hugh

[jjm35]

I may not have explained myself well. What I do is to play 5 pre-recorded backing tracks from the iPad via USB with the software “Multitracker”, which as the name implies, serves to play several tracks on independent channels of the audio interface or digital mixer we are connected to, and apart from that, there are two real instruments and three live vocals. It has nothing to do with recording.
Until now I was doing this with a mixer (Behringer X32, and even with XR18) without any problem in 2 years. It seems that the USB driver of the CQ20B might have some kind of bug or something.

[Hugh]

I have 6 stereo BU track selections on a SanDisk 32 gig SD card. I have set up the #1 soft button for quick play/stop control. In the event you are not familiar with deploying SD cards this is how I do it:
1) The card must be formated first; HOME/SYSTEM/SD & choose Format
2) CONFIG/SD/SD (Set CONDFIG/Inputs to ANALOG for recording) (source point; “post pre-amp”) (Sample rate 96K)
3) HOME/RECORD/Multitrack;
a) Arm all chanels for tracking; (Will have a RED button when active) (Will be greyed out when not armed)
b) Press the “RED RECORD BUTTON” in transport to start recording
c) Press the STOP button to finish and “Allow sufficient time” for finalizing before leaving the setting

Play Back:
In order to facilitate the soft button quick play/stop function I planned on a fixed sequence for the selections, but the easiest alternative, if that is not appropriate, is to leave the I-Pad screen in Home/Record/Multitrack and Press the desired selection on the menu list.

1) Play Back requires resetting the CONFIG/INPUTS to “DIGITAL AUDIO” NOT analog for play back
2) HOME/RECORD/MULTITRACK;
a) Select the desired stored file from the SD card, Then touch the “SELECT TRACK BOX”
b) Use PLAY BACK MODE to select (some, all or none) of the recordings to be repeated
c) use transport bar to control playback

The 20b has two TRS stereo Inputs: I use ST#1 for the subject BU tracks and ST2 for my I-Pod walkin music. Obviously being acquainted with locating the ST channels on the I-Pad screen is important to facilitate controlling record and playback.
Keith has an outstanding video covering most everything I have described and I highly reccommend looking it up and carefully following his instruction. This is how I figured out how to use the outstanding SD card option that is much much better than any USB protocol.
Hugh
Hugh

[jjm35]

Interesting, that could be another simpler way to meet my needs without using the iPad, and just using an SD card with the BU tracks. I would have to see how to create the sound files (I think they are 32 bit Wav files without metadata), I just have to see how to name them so that they are played together by song, since the 5 tracks I mentioned are always simultaneous: keyboards, drums, backing vocals, click, and bass, so that in each song these 5 tracks play simultaneously through separate channels of the mixer. It is set up like this, so that we can go in duo, trio or quartet, using the same backing tracks, just muting on the mixer the channels that correspond to the instruments that are on stage that day. In any case, that would be an interesting setup to use as an alternative (backup), since at the same time as the songs, I launch midi tracks with instructions to handle 8 cameras live in Resolume and change the presets on my digital guitar pedalboard, and I want to continue doing that with my iPad so I don’t have to change the format of each track of my bands’ entire repertoire (literally hundreds of files).

[Hugh]

Please keep us posted with your progress deploying the subject SD card protocol within your work flow. Your need to be able to “customize” the number of BU tracks available pursuant to the specific personel on stage is a different challenge than I deal with. I prepare for my solo show a very careful stereo studio two mix that is a finished recording with careful attention to dynamic expresion, reverb and lead & Back up Instrumentation placement supporting my acoustic guitar and lead vocals. I can fall back on 50 years of acoustic music production to deliver seamless pre recorded BU tracks that I fully well understand most folks can’t do. In many ways your multi-track protocol will be much less complicated however there are several factors that need to be well thought out.
1) Given the CQ processing limitations you would be well advised to retain pro studio production help with the initial generation of the subject BU tracks.
a) The 32 gig CQ SD card limit may require a 24/48 protocol to accommodate your overall file size for the 5 selections.
b) CPU hungry studio Reverb plug-ins that can greatly enhanse instrumental leads are not really an option in live SR with most all digital desks today: but they are never a problem with studio DAW mixes.
c) Try to prepare all BU tracks as “post production finished” this will greatly reduce the processing load on your CQ20b.
2) The biggest flaw in all “KARAOKE” type of pre recorded blending with live performance is balancing the dynamic presentation. Since you will be controlling the individual channel faders it is imperitive to have leveled out DB priorities for rhythm & leads. This will probably be far more important than you now may realise.
Hugh

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