Since I purchased my QC two years ago I’ve identified early on consistent sonic difference between the Headphone output and the main XLR outputs on my Quad Cortex.
My Setup:
· All presets are output in mono (Guitar to Mono Out 1, Mic-Vocals to Mono Out 2).
· Both XLR Output 1 and 2 levels are set to a standard -12 dB for line-level signal, to be sent to a mixer or direct to amps/speakers (depending on use and circumstances).
· Both guitar/vocal signals are balanced between them and volume-matched in the QC HP output settings (internally) and XLR output (in most cases by a mixer and output aux monitor).
My Findings:
The issue I have is that the QC Headphone output consistently sounds much more “wet/rich/full” and more sonically pleasing than the output from the XLRs. Nothing wrong with that, but I find it weird/annoying that I do not get a closely similar sonic output from all other QC outputs.
· The main XLR outputs sound comparatively much “drier” than the QC Headphones output, a character that is replicated exactly through any mixer, speaker, headphone, IEMs or other listening devices.
· This difference persists across all presets and is not a mix-balance or level issue in the QC.
My Guess (after 2 years of daily use in several conditions and scenarios):
This consistent difference in the sonic quality of the QC HP output as opposed to any other QC output (whether going directly to headphones, or to different types of speakers or amplifiers or mixers), is pointing me to the idea that there is a dedicated headphone amplifier circuit in the QC that is imparting its own coloration or frequency response, different from the flat, uncolored line drivers used for the main XLR outputs.
My Question:
Is this a known, documented characteristic of the QC’s design? Not that I am aware of. Has anyone else conducted A/B tests confirming that the headphone output is not a perfectly flat representation of the main XLR outputs and adds its own “sweetening”?
I want to confirm if what I’m hearing is an intentional feature or if this is a particularity of my unit (which btw has been repaired and fixed in the past). Any insights from other users or Neural DSP staff would be greatly appreciated.
I have not experienced this specific issue, but what comes to mind is the headphone feed can be configured and affected by several other settings (separate from the other audio outputs). I’d like to try one of your presets and see if the results are similar on my setup. Are any on the Cloud?
No, never done that. Mainly because I am a perfectionist, and keep fine tuning small bits here and there of my presents. I have about 50+ presents to cover all our repertoire as a band. Each present lives for each single song, with different scenes for the song verses, choruses and solo parts (sometimes also alternative choruses and bridges). But maybe I should start doing that, at least for a few. Unfortunately, I am presently travelling around Europe without my QC in the next 2 weeks, but as soon as I get hold of it I will upload a preset and let you know. Many thanks for your relentless and very helpful advice and help.
are you comparing the headphone out through the same monitoring? If you are comparing listening listening on headphones to room monitors, that would explain it.
Have you tried using the xlr outs to a headphone amp and comparing?
How are you monitoring the two different outputs? I’m gonna assume the differences could be these-
-headphone output is a certain amount of ohms specific for headphones compared to just the XLR or quarter inch outputs
-if you’re plugging the XLR or quarter inch outputs to a preamp, etc you’re coloring the sound further, as opposed to just plugging headphones into the headphone output
-this also could be the difference of using closed back headphones vs speakers or monitors that may be coloring the sound. It’s always best to understand that various venues, etc will sound different with presets compared to just dialing it in with headphones
I’m fighting with exactly the same problem for a while now. The presets generally sounds a lot better via the headphones compared to the sound via the PA/FoH. This brings me regularly in the ennoying situation to have unexpected sound quality problems during live gig’s. I’ve tried it all and my last hope is to connect my QC to an FRFR during creation/tuning of the presets as an FRFR compares well how the preset will sound through the PA/FoH.
fwiw I never dial in presets with headphones. Always with FRFR, first at low volume, then final check at gig volume as it will sound different (that’s biology/psychology, not gear).
I also have an eq as the last block going to FOH so I can quickly tweak if need be given the room.
Welcome on board. Yes, it is annoying because the QC sounds SO good in the HP output !!! Anyways, as most people have pointed out (and I do), the best is to work on your presents by listening them as much as possible to the real-live-gig scenario setup you are going to perform with (e.g. signal going through a mixer and then to PA and/or to monitor speakers or monitor in-ear, and/or FRFR cabinets). My personal preference is to have the QC going to the mixer first and then get the via AUX monitor signal of the mixer directly to my professional in-ears. This is because if you let the sound come out of ANY kind of speaker, the acoustics your are hearing in your studio/room will never be the same to the sound coming out of any different system or venue. That practice would make sure that your tone is as much as possible to your liking and is your exact point of reference (which you can then fine tune depending on the specificity of the location). You have to then accept the fact that if you are practicing/playing/listening to those present only via the HP output your experience will feel much more enjoyable and fulfilling !! Hope this makes sense.
Hi everyone. Further to my post here, I have submitted the same question to Neural DSP QC Support team and, although not really giving a full explanation of the phenomenon some of us are experiencing regarding the HP output, their helpful answer at least confirms that the signal coming out of the QC outputs are NOT the same and comparable.
<<<Thanks for getting in touch. This discrepancy is normal and expected when using different outputs. The output level of the XLR and TRS are the following:
So, more output level is expected if you connect TRS cables to outputs 3 and 4.
The HP output is internally boosted +6dB, that’s why the analog outputs are showing different values in the I/O Settings when you compare the output meter and the headphone meter.
When using the output 3/4 at 6.0dB you are basically boosting the signal +12dB when monitoring Quad Cortex via headphones.
So I can confirm that this is an expected behaviour and your Quad Cortex is working perfectly fine.>>>
many thanks for this very useful information. So, I understand to to have to tweek the presets through for example an FRFR to have a sound more or less the same as throught the PA.
I also suppose that the most tweeking is about the tweeking of the EQ’s. Where can I find the information on how to tweek the EQ ? The exact problem I have is that the presets through the HP very ofthen come out of the PA much to sharp/harsh.
Many thanks
thanks for sharing their response. Sometimes it takes follow-up questions to really get down to the specifics of what you actually asked- don’t know if it’s a language factor or what, but a lot of times it starts out kind of vague and requires more conversation to get to the root of it.
Good to know about the HP boost, I don’t think we’ve ever heard that mentioned before. Guess that’s why 100% on the vol wheel can be overwhelming thru headphones
