Qu-16 USB-B Distortion & Gain – There's a Duck in My Mix

[Miles JParticipant]

I tried the Qu with my wife’s MacBook, same result. Then I tried it with my old 2011 iMac running an older OS, and the problem went away.

I am not aware of any drivers required by the Mac for the Qu. There is a firmware update available, the release notes say there are improvements to USB streaming stability with some computers, but it also says the most recent Mac operating system supported is the one on my old Mac. It can’t hurt to try…

Thanks again for all of your time and attention to helping me out.

[volounteerParticipant]

@milesj

You need to use the old mac!

Apparently the newer opsys is the problem with the Qu.

[Anonymous]

@miles J
Greetings there Miles J 🙂

I’m keen to know if your [Wife’s] MacBook is USB ‘C’ new, small reversible shape or the USB 3, same as the original shape with the blue strip?
Also have A & H authenticated your version of Apple OSX for use with the QU?
Also curious to know your definition of “plenty of RAM” 4? 8? 16? 32? within your Mac that is.
Cheers.
Hope to hear from you.

[Miles JParticipant]

@xyz,

Greetings!

Thank you for your note, I appreciate your help. My apologies for the delay in response – you can measure my latency with a calendar 🙂 I’ve been working against a deadline of yesterday, and defaulted back to my trusty old equipment for this week.

The MacBook has the new, reversible shape.

The good news is, updating the firmware from 1.90 to 1.95 in the Qu seems to have solved the problem of the digital artifact noise.

Cheers!
~ Miles

[budlight4uParticipant]

@miles
Were you able to solve the 2nd issue in your initial post?
2) The recording signal level indicated in the DAW is lower than the level indicated on the Qu channel. The Qu channel can be close to peaking out, and the Logic level still reports plenty of headroom. I see there is a trim control for channel USB assignments, but this shouldn’t that only affect the USB return signal to the mixer? Is there some method of controlling DAW channel gain independent of Qu channel gain?

I have the same problem and plus
Logic level is no where close to Qu channel level. I haven’t found a way to increase Logic level to match Qu or come close to Qu level.
All channels are set to USB B
I/O -> USB Audio
CHNL 1 is set to CHNL 23 where the mic is connected
On Playback, all the QU effects are lost

[KeithJ A&HModerator]

@budlight4u

The difference is because the meters are using two different references for 0dB.

The metering on the Qu is set up so that 0dB on the meter = +4dBu at the output and leaves approximately 18dB of headroom before digital clipping.
In most DAW’s the metering shows dBFS, where 0dBFS is the maximum level that can be represented (where the bits are all 1, so a 24bit sample would be 1111 1111 1111 1111 1111 1111).

There are more details on this, including options for boosting the level if required, here –
https://support.allen-heath.com/hc/en-gb/articles/4403616287889-General-Qu-SQ-Levels-and-Metering-in-Qu-and-SQ

The FX in the Qu are most commonly used in a send -> return setup. So you are mixing multiple channels to send to an FX unit, then hearing just the affected sound coming back on the FX return channel.
i.e. You are not applying the FX to individual channels unless you insert them.
This means that recording individual channels to Logic will not generally include FX.
You can record the FX if needed, by patching FX return channels to USB output channels in the ‘Setup > I/O Patch > USB Audio’ screen.
Also note that you can record from different tap off points of input channels by setting the ‘CH/ST/Grp’ source to ‘Direct Outs’ in the same ‘Setup > I/O Patch > USB Audio’ screen and then going to the ‘Routing’ screen with any input selected and changing the global ‘Direct Out Source’.

Hope this helps 🙂

Keith.

[budlight4uParticipant]

@keith
Thank you so much for the quick response.
I followed the instructions in the YouTube video https://www.youtube.com/watch?v=PIBfl4EV20Y starting at 2:24 is the step by step instruction on how to get Audio from Qu-32 into LogicPro
I have a mic connected on Channel 23 on my Qu-24
In logic, I create a new Audio track. I can only get audio Signal from Qu-24 to LogicPro if I choose Channel 23. This is apparently contrary to the instructions on the video where he chooses Input 1
The metering on the Logic Pro in the video when he arms his Audio track (the mic connected to channel 25) is something I have tried very hard to get that level to no avail

So for sending Audio from Qu-24 to Logic Pro, only Channels 1 & 2 can stream to Logic Pro according to the video ? see video starting at 2:24

Response to your suggestions:
“You can record the FX if needed, by patching FX return channels to USB output channels in the ‘Setup > I/O Patch > USB Audio’ screen.”
I patched FX1 Ret L & FX2 Ret R to Channels 1 & 2 – I’m pretty sure this is not correct

Also note that you can record from different tap off points of input channels by setting the ‘CH/ST/Grp’ source to ‘Direct Outs’ in the same ‘Setup > I/O Patch > USB Audio’ screen and then going to the ‘Routing’ screen with any input selected and changing the global ‘Direct Out Source’.

Using Channel 23 which the Microphone is connected to:
Global Direct/Direct out source is set to Post Insert – again, I’m pretty sure this is incorrect too

PS – Does A&H offer over the phone technical support on a per hour fee that I can utilize ??

Thank you in advance.

[KeithJ A&HModerator]

@budlight4u

For support over the phone, please contact your local distributor, you can find a full list of our distribution partners here – https://www.allen-heath.com/where-to-buy/
You can also contact us directly through our support portal – https://support.allen-heath.com

But some points that might help here first (and for anyone else who might come across this post)-

• The USB channels can be thought of as wires that connect between channels on the mixer and channels in your DAW. So you can connect (patch) any output from the mixer (input direct output, FX return, mix) to an input channel in the DAW as well patch any output from the DAW to an input channel on the mixer.
• If you do not change the default patching, you will get the input direct outputs from mixer channels 1-16 on USB channels 1-16, main L&R on channels 17&18 (as these are also used for stereo recordings) and direct outputs again on USB channels 17+. But each USB channel can be fed from whatever you want. The video you linked to shows the process of patching the input direct output from mixer input channel 25 to USB channel 1, but I’d advise patching 1-to-1 where you can as it’s less confusing!
• The ‘CH/ST/Grp source’ (the direct output tap off point) is completely up to you and depends on how much or how little of the processing you wish to record. For example, if set to ‘Post PEQ’ all processing up to and including the PEQ will be sent to USB. On the other hand, if set to ‘Post Preamp’, your recording will not include any HPF, Gate, PEQ or Compression processing.

Cheers,
Keith.

(I’ve not addressed the metering and levels further as all the information on this is covered in the knowledgebase article linked to).

[budlight4uParticipant]

@keith
Thank you so much for your guidance. I was able to finally solve the problem I was having with QU-24 effects missing on Audio tracks I recorded via Logic Pro.
On Fx 1 and Fx 2, I had raised Channels 23 and 24 (vocals) to unity. Channels 17 & 18 which are Main L & R and USB B in Processing/USB Audio (Return signal from Logic Pro) were at zero.
I raised Channels 17 & 18 faders to unity in Fx 1 & 2. Now, I am able to record audio track in Logic with QU effects reverb, delay and etc.
Once again, thank you for your step by step guidance.
Love your webinars and live events. Keep them coming.

Cheers!

[Author]

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