Hi there, I’ve had my CQ-18T for a few months now and am generally very happy with it. I have a couple of upcoming gigs at a small venue where more than a single powered speaker is not logistically possible or acoustically desirable. We’re only putting vocal mics through the mains, but I do put on music between sets via BlueTooth. I would prefer to connect my single EV-ZLX12 to the L Main XLR output.
My question/concern is: Will I only get the Left channel of the Bluetooth stereo signal in this configuration, assuming nothing is connected to the Main R output, or will the mixer handle the stereo->mono conversion? If it doesn’t do that out of the box, is there a way to configure it that way?
To my knowledge, there is no way to bridge the LR output down to mono on CQ. Mono inputs, that are not panned, won’t be a problem but, as you said there is no way for you to guarantee that (what comes in on Bluetooth Stereo) will have an equal image on L and R from within the mixer itself. I just did some testing on my CQ with audio files that had only L and R components and don’t see a way to do what you are asking for.
However, I’m using the an iPhone as my bluetooth source and there is a setting under accessibility/Audio&Visual where you can turn Mono audio on. Can I suggest the making the audio mono at the source will be your easiest path here?
Please do not purchase this cable for this purpose, as it is not a combiner but is intended for connection to devices with an unbalanced stereo input.
If you connect it to an active speaker with a balanced input, you will not only lose the balance, but you will also only get a differential signal from the L and R!
However, if you have one of the 6 outmixes available, you could use it (Post Fader, Post Comp, and all faders at 0 dB) and get a mono signal at the corresponding output.
Thanks. Yes I have all 6 outs available. Will I have to do anything special (still waiting on the mixer to be delivered). Is there a setting I need to use or just use a 1/4 to xlr cable out from output #1 and I am good to go?
Again appreciate all the help for a newbie.
Edited my original comment with what appears to be a better suited cable.
Was late when I posted and only really looked at the pictures rather than reading the listing I shared.
But keep in mind what others have said, as depending on your sources, you might encounter polarity issues.
If you are in any way decent at soldering, you could perhaps make one of the cables up yourself with bits you have lying around, to save on money so you can try it out without having to spend on a new one.
But please not just plugs and cables, because you can’t, or rather, shouldn’t, simply connect two outputs in parallel.
That won’t be the case with your second Thomann cable either.
So this way would really be the best and cheapest option.
As I already wrote:
For this mix Post Fader, Post Comp, and all faders at 0 dB
Set the output to be ‘Post Comp’ and ‘Post Fader’ then set all the faders including the FX returns for the output to unity. Set the output’s processing as you like it, perhaps to match what you did on the Main LR.
You then just mix the main mix as normal since the AUX’s mix is post fader at unity it just mirrors the main mix but the mixer has to sum to MONO.
You couldn’t just a use an AUX mix as a replacement main mix by actively mixing it instead of the main mix, because the FX sends are post main mix fader for each input (to avoid hearing source only through the FX). It would get confusing about how much signal was being send to the FX. The trick to know is those output settings to mirror the main mix’s faders basically.
Obviously use the correct AUX output to feed to the amplification and ignore the L+R outputs.
Do not use a splitter cable as a summing cable. Search for ‘Rane Note: Why Not Wye’ for the reasons behind this.
While it would work for your described case, it’s not a good recommendation in this case because you wouldn’t be able to sum two outputs with it either - as with the adapter above with the same wiring:
I honestly don’t know what’s happening inside the speaker, at electronic level just after the mono input in terms of signal phasing/dephasing, but all I know is that’s working just fine.
It’s not about what happens after the mono input, but before it.
Because your board doesn’t provide a signal for a balanced mono input, but rather for an unbalanced stereo input.
So, in addition to the loss of symmetry, you only get a differential signal between L and R, which means that, for example, all sources located in the center of the stereo image are canceled out and no longer audible.
This is very interesting. Thank you for the explanations.
My PCB above was initially designed to have a stereo OUT from 2 CQ AUX output, to be able to directly plug a stereo headphone.
The fact is that it is working fine for amoricanseth users case.
Well, I thought is was working fine as I can’t hear any loss in the signal when plugged into the mono input of my Polar HK10.
But you raised a doubt and now it is a bit of grey area to me and I will do some test with sin waveform.
I couldn’t explain why it should work on this active speaker with your adapter board to unbalanced stereo.
You don’t need any special test signals - any other stereo or mono signal will do just fine.
All you need to do is send it in equal proportions via the two main LR outputs from your CQ to your board (or to an identically wired adapter cable) and then connect its stereo output to a mono input on your active speaker.
Now you should normally notice that mono signals from the source practically disappear completely when panned to the center, and that everything that’s more or less in the center in stereo signals is lost - for example, the vocals.
The same should happen if you send the stereo output signal from your board on the CQ to a muted input without (!!!) phantom power and then monitor it via PFL.
(What you could do, of course, would be to send the two Main LRs separately to the two inputs of the active speaker using two XLR cables and sum them with their mixer. But that wasn’t the topic.)
I will try that, thank you for your explanations.
What is unclear to me is that with my PCB I use only the pin2 of the 2 XLR, there have same phase and they should just sum-up inside the speaker with no phase cancelation.
Well, all EV-ZLX12 I saw on the net had 2 inputs… maybe it is another version.
No, they shouldn’t!
They would only sum up if both signals (decoupled!) were sent together to Pin 2+ of the output.
But you yourself wired it so that one of the two sends its positive signal (2+) to the negative pole of the output (3-).
And so, with the same signal (phase), there is no sum, but rather a difference with full phase cancellation.
