QC sounds all muddy

I’m plugging in a MIM Tele, which is pretty bright on my Mesa Roadster. Most of the QC’s factory patches sound muddy and dull. If I crank down the bass and crank up the treble and presence on the preamp, it helps some but it still sounds pretty dark and lifeless. Yes, I upped the impedance setting. Really stumped.

Starting to worry that I might have a bad unit. Thoughts?

You’re comparing your amp sound to a miced sound that QC produces. I have noticed the same thing, that QC doesn’t have lots of those ear piercing high-mids/highs that my tube amps have. But when you use a mic to record the guitar sound live or studio you want your sound to sit nicely in the mix and I have noticed that QC does exactly that with it’s ”dark sound”. I actually find it dark only at low volumes(=volumes when I don’t need earplugs).

Try to turn your monitors volume up to gig volume and you will notice that the sound from QC is actually perfectly balanced guitar sound for studio recordings and gigging…at least in my opinion :slight_smile:

And I mainly use only captures, because they just sound so much better than QC’s virtual amps. On virtual amps I find I need to lower the bass to somewhere 1-3 and treble around 3-4 to get it work.

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This could be many things including what @Calebzki is talking about. If you’re in serious doubt about your unit please contact support and they can assist you further: https://support.neuraldsp.com/

As for general troubleshooting: Do you observe this dull tone on all tones on the QC, or just the factory ones? Do user-made presets such as these sound drastically different on your end than what was heard in the demo? Curious as to what’s going on here.


Is it muddy through headphones too? Need to determine if its your monitors or speakers?

Thanks for all the troubleshooting tips, guys. Sorry, I’ve been occupied with other stuff but hope to walk through all these various steps in the next couple days. I’ll report back.

I think your post on FB indicated you were using another audio interface and we’re planning to use your QC as your interface etc. What was that outcome?

Still haven’t tried it. That’s part of my next steps. Too much other stuff going on last week or so, unfortunately. But soon. :slight_smile: Thanks for asking.

Okay, I’ve finally done some comprehensive testing in line with everyone’s suggestions. Here’s where I stand…

  1. overall muddy sound: well, having now tried it on headphones, studio monitors, and a powered P.A. speaker, it seems much better. True, many of the factory presets need heavy EQ tweaking to get them to a semblance of usability (and which I don’t understand, since I’m using a Telecaster that’s actually pretty bright), and some I can’t even get to the point of usable, which is even stranger. But many are also much more balanced out of the gate, and more easily tweakable. And, yes, I’ve learned and agree that the factory amp captures by and large are better at this than the amp models. And tend to sound better overall. AND Rabea’s presets were a good A-B comparison tool. His presets sounded very similar on Youtube vs. on my QC. Yay!

  2. headphones aren’t my favorite way to play through the QC. They often just don’t sound that good. I also seem to notice odd artifacts like fuzziness on the lower notes, especially on the low E string, even on clean presets.

  3. My Mackie HR824 monitors sound pretty good with the QC, but lack the punch that larger speakers can deliver (these have 8-inch woofers). I tried these both directly from the output of the QC and running the QC into my regular audio interface’s hardware mixer (so I didn’t have to go through the computer). One thing that was pretty bad for both headphones and the Mackies was that noise. Primarily RF getting into the pickups, I think. Pretty screamy. The QC’s noise suppressors helped, but it was still pretty annoying. Got better when I moved away from the computer/monitor later on, though.

  4. My QSC K12 powered speaker probably sounded the best of all these, but even it isn’t great due to what I think is an inherent scooped frequency response. I think there may also be a bass bump that detracts from what it should sound like. Not very FRFR.

  5. Part of my gripe has been what seems like a lack of top end. Like there should be harmonics above 5K that just aren’t there most of the time, if ever. When I plug into my Roadster’s or Bugera’s clean channel, I can get nice, bright highs coming off my Tele. These seem very elusive with the QC. There were a few times I could dial something like this in, but it rarely felt as present or as bright as with my real amps. Not sure what to think about this.

  6. It appears to be close to impossible to get a truly clean sound on the QC. Even notoriously clean amps like the Twin or DLX or Prince(ton) break up (with the amp model’s volume (gain) knob way down) if I hit some chords hard. This simply isn’t accurate to real clean amps. And sometimes I really want those truly clean sounds. Ideas on how to achieve that are welcome.

I did get some truly impressive sounds. Another issue I noticed, though, is that the high-gain sounds that I tried have a kind of scratchiness that obscures the detail of what I’m playing. For example: the individual notes of the recurring riff in Interstate Love Song are really hard to hear when played on any QC high-gain sounds that I’ve tried so far. Even the individual notes of the jazzy chords in the verses aren’t really discernable. They’re sort of lost in the white noise. Ideas welcome.

I guess my next step is to get a true FRFR speaker to give the QC a fair overall shake. I’d try my Mesa 4x12 OS slant cab, but who wants to lug that around all the time? Not me. Maybe occasionally, for the right gig. Maybe not.

Thanks for everyone’s input. There are so many great features. Hopefully, I’m getting close to loving this thing.

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Hi, I have the exact same issue! Been fighting this for months. I also have wondered if there is something wrong with my unit as everyone else seems to have no trouble getting great tones. Seems a bunch of harmonic content is missing. I would love to do a test if other owners were willing to help. I could record some guitar phrases direct (no QC). If other owners could take those and, using the reamp flow via USB, process them with specific default presets, we would have precise recordings to compare. Any takers? Thank you.

Count me in. Would be a great way to do the A-B comparison rather than try to describe everything and hope we’re all understanding each other.

@Alezalles Don’t want to discourage your testing but have you tried the Rabea presets linked above? (if not, check these out: My 8 Presets For Quad Cortex - YouTube)
The first test I would do if you’re in doubt in your unit is to see if these presets sound the same on your unit as they do in the demo.
Beyond that, you are more than welcome to take DIs and compare, but please reach out to support directly (https://support.neuraldsp.com/) if you believe you have a faulty unit.
Otherwise, happy testing!

Also @dlabrecqoe Thank you for taking the time to troubleshoot and test your QC to this extent. There are so many factors at play that could influence your sound and I’m glad you took the time to explore many of them. Best of luck and I hope you find a tone setup that works!

Thanks. Sounds like you missed part of my post, above. Yes, I tried Rabea’s presets, and they did sound very similar on my end as on YouTube. So, thanks again for that. There is hope. :slight_smile:

Oops. Now I see that you intended that (the reprise of the Rabea presets suggestion) for the other guy, here. Sorry.

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Hi, thanks for your post. Yes, I have compared what I hear from my unit to Rabea’s and some other preset walkthroughs, and there is something not quite right. My unit sounds flat and and lifeless. Of course there are other factors involved (the actual guitar, cables, and not the least of all, the player). I have noticed something significant. If I record the di guitar through the QC and compare it to a recording of the di guitar straight into my focusrite’s input, there is a huge difference. The QC sounds tinny, pointy in the highs, and lacks midrange. So I thought that maybe there is something going on with impedance, however, running the guitar into a direct box and using the mic setting on the QC input yields the same thin results. My perception of the QC tones I’m getting is precisely that they sound very DI, not vibey at all. So this could explain that. I suppose it could be an issue with the A/D conversion. I will contact support. But if anyone is interested in helping, I’d be curious to see if you hear a great disparity between di sound going through QC and sound going straight into another interface. Thanks!

Initially, I was running my QC through an older Presonus 1818VXL interface via QC TRS OUT3/4 then eventually migrated everything to QC as my only interface and for me, things only got better etc. My tones have always been phenomenal IMO. Currently I’m running my XLR OUTs1/2 direct to my Allen and Heath mixer then out to the PA. OUTs 3/4 are now running to both a 5150II and Dual Rectifier FX return for stereo power amp. I usually keep my mixer EQ pretty flat etc.

To my ears, the QC tends to sound very close to the real amp; however, my captures lose a small amount of what I would call “3d sparkle”. As an example, compare these two captures I made.

Twin Reverb Neural Capture

Twin Reverb SM57

The neural capture is very close to the actual amp (mic’d); however, there’s just a little something that’s missing (complex harmonic frequencies in the higher range).

I’m not losing any sleep over this, as it makes very little difference once the guitar is part of a mix with drums, bass, vocals, etc, and the QC offers so much flexibility that I’m willing to accept that it’s not “perfect perfect”.

Also, if you’re listening with headphones, I’d highly recommend adding ambience to the end of the chain, as that makes a big difference in how flat things sound in your cans (flat by design btw).

If you use the QC with a normal amp, using an “out of the box” amp preset, it will sound muddy.

Why? Because the QC adds its own amp and speaker emulation. These (especially the speaker emulation) act as EQs which color the sound as if it were going through an amp. Most of that coloration is high-end roll-off coming from the speaker emulation. It will sound “right” and “natural” through headphones, or going direct into studio monitors or a decent PA.

However, since you’re sending the signal to a real amp, that emulation is redundantly being superimposed over the real thing, causing the sound to be muddy. So, if using the QC in front of a normal guitar amp, simply disable the amp and speaker emulation blocks. Then it should sound “right” and “natural”.

Alternatively, use a FRFR (full-range flat-response) amp, which doesn’t add its own coloration, thus allowing the QC’s emulation to show through and to sound “right” and “natural”.

[Edit] Alternatively, in a live setting for example, add a signal splitter before the amp and speaker em. Send the non-emulated signal to your amp, and the emulated signal to PA / monitors / headphones.

Tmountain, did you volume-match these and then do a blind test to see if you actually can hear a difference? :slight_smile:

I agree that one sound a little more “deep,” but I have to wonder if that’s not a simple volume difference. Or even a slight difference in the performance (if they’re not from the same take).

dlabrecqoe, I did not. I probably should have been more scientific about it. I just got a speaker simulator recently, so I may do some more precise experiments with its line out to see how close I can get the neural capture to the original. That said, I’m really happy with my QC, so it’d be more for curiosity than anything else.

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its the ribbon mic on the cab