I keep thinking I am gonna sell my QC, but then I get back on it, and change my mind.
I don’t know what it is about the sound of the QC, but it has something the others don’t. I can get real close to it with my other modelers, but it has a depth to the sound that others do not.
What it lacks in effects, it has in tone.
Does anyone else have an opinion on what it is that I can’t put my finger on? What is it that just makes it so pleasing in response and to the ear?
For me it’s the response and dynamic. The QC just sounds SO! real, not that digitally processed (like i know from plugins or other modelers like the Helix Rack)
I actually don’t play my tube amps anymore since i’ve got the QC because it’s more comfortable having all the sounds in place without sacrificing the amp like feeling / response while you hit those notes.
At one time I had a helix, an FM9 and a QC. I played them all side by side after trying to find the best sounds I could on each respective unit.
The QC always won. I don’t know exactly what it is but it is very addictive and lively to play. The weird thing is when I capture my amp (on a setting I love) I often find I love playing the capture even more. Bizzarre.
I know a lot of people are pumped about the stadium (including me) but I have two QCs now and they’re not going anywhere until I can test them both side by side.
I had the same experience. HR, Kemper, FM3 and tonex right beside the QC and there is something natural about it.
can’t explain it. But it just has something extra.
“something” Is subjective
For example for me there Is “something” in mid highs of QC that Is innatural and too much dense …imho 
and i hate this behaviour, finding another plugins of other specific brand more authentic and Natural on this aspect 
“Sound” is subjective. as is “tone,” and “best”, and all “preferences”.
Well our hearing is the really the difference on whether you prefer this over that… age is another… also our ear flaps the bits on outside of our heads are different for all of us down to ear canal size shape etc our tiny bones that transfer sound from the drum to the inner ear and to our brains… trying to be simple here in what I write…
we all hear differently basically none of us are actually rite in saying this modeller is better than this modeller.. Or sounds more natural…it’s simply what we perceive ourselves… saying things like the QC/NDSP plugins has unnatural mid and high frequency content, could actually be a problem with your own hearing or you may be right… or it actually does have more natural content in those frequencies than any other modeller on the market that may be missing this energy in those frequencies…
we get very defensive in our opinions of things, these are tools for us to get a job done if prefer one over another just use the one you prefer..
I’ve done a lot of research in to hearing through the years and have learned so much from my own ears…and the issues I’ve had to deal with because of them…
And just to also add for me the ndsp stuff sounds the best… I’ve had so many guitar plugins modellers bla bla bla the only ones I like is Ndsp… there just my preference…. What my ears and brain prefer
Well sure.
That is all accurate.
The sounds we prefer ignite pleasure sensors and make us happy.
The QC just makes me happy, but I cannot put my finger on exactly what it has that the others I play are missing.
that’s the fun of it all.
The down side is I drive my wife crazy. “I’m selling it”. “No, I played it and its just so good”. “They aren’t updating it, I’m selling it.” " “No, I played it and I can live with it like it is”.
I am hilarious - in my own mind.
That’s exactly it whatever makes you happy, just use it and carry on being happy. 
I’ve had ear ops on both ears one big one and odd things in the other without going into it… I can now hear very different from 20yrs ago and it has become very helpful when on stage even down tuning of other instruments in the band… I can now tell who needs to retune even down to the drummer 
or what string on the other players instrument mid song or even when I’m soloing I can home in on the rest of the band and the tuning is down to a few cents+/- it’s a weird phenomenon that my doctors can’t explain… nor can the band members there perplexed it’s actually too long of a story to put in text…
But none of us can say with any certainty what is the best…
I have analyzed the QC’s model and capture waveforms and have determined that they are embedded with an ultrasonic message that causes the human brain to become addicted to the sound. There is no escape…You have been assimilated!
Even if NDSP never released another update for the QC, it would still be the best investment in music equipment I’ve made in my life as a musician so far.
I think it feels and sounds better than the two I used to have. I guess I can mention them. The helix and Kemper. I never played a song with either of them. I was too busy tweaking them. The quad is a quick set up and I immediately felt it was closer to an amp like feel and I like the sound better. It’s also fun too fool with the the UI. I also don’t want to be connected to a computer. I’m fine with it. I don’t care about plug ins. I grew up on amps not plug ins. They are my first choice but the quad is staying. I also see pros using it and it sounds great. I don’t capture my amps & pedals but it can do that if u need to. You’re not a the only one I heard that sold it and rebought it. Cheers.
Exactly, When I compared the QC with Neural plugins and the Axe-FX, the Axe-FX felt about the same as the Neural plugins on a mid-range PC in terms of response and dynamics, but the QC was in a completely different league. I expereienced this at most with breakup presets.
TL;DR I did an experiment to figure this out some time ago. Since I’m sitting here on standby, what better use of my time than to share the findings! If you read the full breakdown below, this will make much more sense but the synopsis is: the QC’s capture of the reference amps showed observable differences when compared to the Kemper Profiler Stage Mk.II. These differences were sonically and visually observed, using a DAW and spectrum analysis plugin. Using 3 reference amplifiers (clean, dirty, high-gain), the QC presented more midrange frequencies in its captures, specifically within the 400-500Hz range, across both the clean and dirty reference amps. For the high-gain reference, the QC presented this similar bump but extended further in the range of 400kHz-1kHz. Since the QC reproduces more of the midrange found in the references than the Kemper, and in consideration of the human ear’s natural proclivity to responding positively to midrange frequencies at appropriate SPLs, the QC offers a more sonically accurate experience than the Kemper option and as such can be perceived as generally more pleasing to the human ear.
It is worth mentioning that the experiment conducted, which I detail below, could be recreated in the same environment to produce the same results. All hail the scientific method.
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If you got this far and are still reading, well, thanks! Grab a cup of coffee and settle in. Since I’m sitting here waiting and enjoyed your question, I imagine my conclusions may be of interest. The conclusions were gathered from one of the many “nerd nights” my friends and I often get into with gear. In this case, it was A/B-ing my Quad Cortex with his at-the-time newly purchased Kemper Profiler Stage Mk.II. You know, I feel rather lucky that my friend group is so heavily invested in music, because gear talk and gear swapping has been our world since we met in our late teens, and there’s always a piece of someone else’s rig living at another person’s place. We’ve all run a gamut of sorts between analog and digital setups, but between the guitarists, the major bases have been covered in terms of modelling. We grew up on combos and gigging, so we know the amps and pedals we like. And I’ve talked about it on this forum before, but my physical need for an amplifier and pedalboard pretty well ended with the QC. Prior to that decision, I’ve put in my time with Fractal, Line 6, and plugins as well, so I’m at least informed on the capabilities of modelling gear in this guitar-centric space (but always still learning)! Now, for your question: “What is it that just makes it so pleasing in response and to the ear?” When my buddy got his Kemper, we had to put the new gear through its paces: this means busting out the manual and bringing out some amps to reference! We’d play some presets on each others’ unit, then make some captures/profiles of the referenced amps, then compare to our hearts’ content. We A/B’d not just with our ears, but also with a spectrum analyzer (Voxengo SPAN) for the visual representation of what we were hearing. I ran the DAW side of things, using Logic specifically. Opinions can’t be measured, but frequencies can — so with the tools and gear ready, we’d be able to objectively pinpoint specific frequencies and ranges that would come up in a comparison (and Voxengo is great for this because it has integrated LU/LUFS metering right in the plugin; it certainly helps with matching track levels quicker, I found). Keep in mind that the purpose of the nerd night was purely observational and exploratory, and not to see which option between these two pieces of gear was the ‘winner’ so to speak — since technically, we’d already made that decision with our wallets. So, with that context out of the way, here’s what was observed in our capture and profile comparisons. I’ll start with some specs:
After all the dirty work had been done, the listening portion began and the differences between my QC and his Kemper were indeed distinguishable:
The prime difference was a more pronounced midrange observed in the QC captures of the Fender and the Budda, in the 400Hz-500Hz range. The 5150 was bumped up as well on the QC captures, but from 400Hz up to 1kHz. Treble and bass variances were existent, but the deltas were not significant enough to note, with the justification being that in a live environment/jam/studio session, these variances would be indistinguishable when additional instrumentation had been incorporated
It’s important to note as well that the stock 5150 III Red/Blue options on the QC were more dialled in for our tastes than what we achieved with the 5150 reference (and yes, I am aware that they are different amps altogether — but fundamentally from the same series, so a similar sonic character was observed). Of further note, Kemper has a profile of a 5150 with a baked-in Tube Screamer in front of it (“Pea V 150 TS9”), and it sounded near identical to our 5150 but with ≈3.0dB of added gain and an uptick in the 2kHz range. Adjusting the 5150’s lead channel post gain knob clockwise reproduced this ‘uptick’ in near-identical fashion.
Here’s what we walked away with: first off, make no mistake — both pieces of gear sounded fantastic, and Kemper makes phenomenal equipment. Full stop. However, that night lives on in my head, because the QC just sounded better to me, so I asked the same question you did essentially. From the A/B-ing between everything, I posit the claim that the QC “sounds better” because it was capturing the midrange more effectively, and when we listen to and/or play through these captures at appropriate SPL levels, we are hearing more of the reference’s nuances that we otherwise would miss if the gain settings were pushed to drive the amp to that point of ideal saturation (this point, though, sometimes comes at the cost of crossing the threshold of pain for human hearing — especially in the case of the 5150).
With a more apparent midrange, we’re hearing more of the captured amp’s character in the QC’s case. And since the human ear is naturally and primarily tuned to hearing midrange frequencies associated with human speech, you’ll see how some of the frequencies line up with our nerd night conclusions. See the chart below: it is an excerpt from the ‘The Psychology of Language’ that showcases the human audiogram; the solid line is the minimum audible threshold as a function of frequency (the minimum sound level at a given frequency which a human subject can correctly perceive at least 50% of the time). Note the shaded grey area for frequency/SPL levels that correspond to conversational human speech. I. Martínez, Professor of Human Evolution, Alcalá University, October 2012).
Therefore, with the presence of that extra midrange in the QC captures in comparison to the Kemper profiles, the logical conclusion is that at an appropriate SPL level, the QC offers a more pleasing listening/playing experience because it is sonically producing more of what our ears are naturally tuned to hear. Voila.
A few caveats: to avoid confirmation bias here, let me address something I’m sure we know but bears stating regardless: there is considerable variation between what frequencies people can hear and how they are perceived. Every ear is different, which is why the human hearing range is averaged as a common band of 20Hz-20kHz. So, clearly, subjectivity comes into play when we discuss how sound is ultimately interpreted. Things like hearing loss, directionality, digital amp model capture quality, hell even the age of the player’s ears… these are just a sampling of the small idiosyncrasies that can wildly impact the final interpretation of any sound. So I do take that into account. Just because it sounds good to me didn’t mean the Kemper was bad, and as my friend stated, he’d take sound of the Kemper with the “everything else” about the QC. His preference was different, therefore he is correct in what he sees as ‘the best option for him.’ I’m happy he found a piece of gear that’s inspiring.
It’s also why I find it odd that some people choose to bash others’ gear for how it “sounds.” In that event, those people that dole out such comments are likely doing more for informing others about their character as opposed to contributing to the discussion on their own subjective sonic preferences. But that’s another topic for another time. Forums are for learning and sharing, and I even learned some stuff about comb filtering recently through here, so it’s a great exchange of information. I hope what I brought to the table offers some insight, and I’d love to hear what anyone who made it through thinks (especially you, @Drjoeljr!). Thanks for reading.
Excellent post, thanks for sharing and it’s very interesting!
That is my kind of nerd night. Great explanation.
I think that is a more than reasonable conclusion. And I also agree that there isn’t ever going to be a winner. Preferences are just that.
I also think that usage of the overblown null test as the end all be all falls short. I like your approach and think it provides information that is more useable and defendable.
I appreciate your response. I think it will be read and evaluated many times. When we get to a place as individuals that we can’t learn anymore we become pretty useless. This is insightful and educational. Thanks.
I’ve had them all and to be honest they’re pretty close on download presets/profiles. But the QC Has a greater range / quality when altering these downloaded files, it has, in my opinion a more natural responses/true amp experience.
This is certainly one of the best posts I have ever seen in this forum. It is sound, rational, and unbiased. It leaves ground for honest difference of opinions with refreshing civility. Your efforts here deserve the thanks of every member of the forum.
I did some playing around comparing some modelers. This time I was trying to create an acoustic preset that will work both with a Taylor 712 and a Martin d28. I am using guitar IRs to “naturalize” the sound.
coming fresh off of the read about midrange, it was easy to notice. Definitely more presence on the QC, more natural mods, but not in an obnoxious way.
I compared 3, had a non player listen, and picked the QC every time. Just more pleasing to the ear, in a subtle way.
your info helps a lot.
Great job, Keith! A very thorough analysis. The OCD side of my personality feels pretty threatened, though. Thanks for sharing your findings.
