It’s been almost 3 months since I started using the Quad Cortex.
While using it, I discovered that there were rogue frequencies at 1.5kHz and 3kHz, which didn’t exist in my guitar + pedalboard setup. So I inserted a 3-point EQ to cut out those rogue frequencies. I compensated for the reduced sound with a boost to balance it out. Interestingly, the rogue frequencies were precisely at 1500 and 3000 Hz.
At first, I suspected certain presets, but all of them had the same rogue frequencies. Even with all effects turned off and using pure clean tone, it was the same. The rogue frequencies were there.
Also, when using the LED blink metronome, another rogue frequency occurred, so I turned off the blink as well. LED metronome is a nice feature to have, but it seems to generate a subtle noise inside the machine.
These rogue frequencies were particularly noticeable during natural sustain fade-outs at the end of songs. Using an adaptive gate made the disturbing sound and fade-out appear, and then everything disappeared abruptly at the end, making it very messy. Eventually, I solved it by using EQ.
But is it just me? How about other Quad Cortex users? I’m using the latest QOS 3.x version. (I update immediately when an update is available, so it’s probably the most recent version)
I don’t know if i have the same problem, but me too i hear unnatural frequencies on mid highs.
Recently i have bought a Flex prime headrush, and cleaning distorted sounds with dynamic of the pick, i hear that the sound of Flex are more organic on higs and mid-highs and the Flex with 4.0 firmware cleans a lot Better and in Natural way.
Qc sounds are top at hard picking, but when i reduce with pick the dynamic i hear disturbing and not completely Natural behaviour.
The string character Is falsed.
Aliasing? I don’t know. I have some sounds on my Channel on QC, i think they are good, but in the last time, for these reasons i prefer the Flex Prime …argh!!
On QC you cut…cut…cut, but this behaviour Is always present…damn.
At the light of screens that put in evidence the aliasing of QC…probably we are disturbed from this.
Ah…all this on MODELS!! (and only), because good captures are a lot Better, and in the past i was super confident on the models. I was One of the most defensor of QC models… Today…not. They are good models, but there are superior models, and yes, i’ m not crazy…headrush Today (4.0) sounds better.
And not from YouTube videos…this thing Is under my fingers, i HAVE QC and Flex in house and with presets from scratch.
QC sounds are really good (Today fun with the new 64 Deluxe for example), but with artifacts…expecially with distorted sounds… probably this Is the used tecnique in modelling creation.
53 years old here, a lot of tube amps sounded and DIY made too… but this doesn’ t matters in fact; i think a lot of us are hearing this
Not sure what you mean by " rogue frequencies". Are you talking about exagerated frequencies? Are you sure it’s not your speakers or your room? Do you hear them when using (quality) headphones?
strange highs always present, not “cut-related”, on mids too.
This video to explain my sensation … i report my considerations under the video:
“Same IR on the two units
Imho HR is more natural…!
At first listening, QC might seem fuller, but in fact, when you try to cleanup the distortion with the pick, Headrush (firmware 4.0) seems more authentic, the unit behaves like the real marshall, and it has more “respect” for the string soul.
And this at the end on the whole sound (and not only with this amp).
Quad Cortex has strange highs (not too much… but strange) on mids and mod-highs (try to hear the cleanup sequences… strange fzfzfzzfzf always present)
All this… imho”
@sledge76 What are your exact EQ settings for cutting those frequencies if you don’t mind sharing? Frequency, Q and gain for each cutting EQ move you make would be interesting
I do hear a difference in Niksounds video. The fizzzz that you often hear in modeled overdriven amps has been complained about for years. I recall reading complaints on the Line 6 and Fractal forums. These high harmonics are a natural element in many amp’s OD sound. Most people never notice this because they don’t listen to their amp with the speaker pointed straight at their ears and their knees never hear it.
The difference between the Headrush and QC models could be due to the particular speaker or mic that was used or even how it was miced and processed when it was modeled.
I’m not a fan of the fizz either, when it’s excessive but, a little bit can add texture and help the tone cut through a mix. I think you’ll find that a low pass/high cut filter can be your friend here. You can use the one under the EQ tab in the QC’s speaker block or by using a high one in an eq block placed after a speaker IR. I usually start at around 7khz and start adjusting it down until I find the tone I’m looking for. I tend to use high cut and low cut (to control rumble) filters in pretty much every preset. Even in an “edge of break-up” preset, you’ll find that a high-cut can trim away the “rattle” you often hear as a chord or note decays and can make the transition from clean to breakup smoother and more natural sounding.
I’m not sure about the rogue frequencies that Sledge76 is referring to.
Same ir in my video with 6900 cut.
I Will post a video on recto, more clear.
As DIY amp builder…this type rattle was a bad polarized tube by me
Ok on heavy picking… but too much unbalanced when reducing dynamics.
On recto Will be more clear what i mean.
In QC It’s not related at bad tube biased OBVIOUSLY…or related on specific amp modelled…but It can be aliasing or capturing tech to create models. On all amps that crunchs. The behaviour has too much artifacts.
I’m not the only One…but a video on Recto in these days Will clarify
Ah…all my observations are in pov of improvement of this Little Drake.
4k is a frequency that’s often cut for real amps/cabs. The high mids are definitely an area where amp modelers can struggle. This is a common issue across all modelers.
The 1.5 region is usually more associated with the pick/attack sound of the guitar/bass. This can absolutely be accentuated by a modeler, but is a common frequency that can pop out, especially depending on the guitar/pickups and technique.
@ DavidRSTV This is my sample preset for the song Hoobastank - The Reason. Neural DSP Technologies - Algorithmically Perfect. I had to use double 3-param EQs at the front to completely cut the 1.5kHz and 3kHz out. Now I don’t have unnecessary noise when I don’t play anything. But the downside is that I have no sound at all from 1.5kHz and 3kHz which hurts the musical quality.
I think the best way to describe the problem would be to make a small YouTube video about it and let you hear the difference. I will prepare the video soon. However, it looks like I am the only one having this issue. Hmm…
@Niksounds Do you mean the sound of fiz in 2:33 in your video? If so, I hear it and if it’s not from intention, the sound is not right to me. My problem is different and it happens even if I don’t play anything at all. The sound of exact 1.5kHz and 3kHz is always there.
Try the following ….
Place an adaptive gate in the second row with a crossover splitter frequency 700 Hz.
Set the splitter at the first position of row one.the mixer on position three row one.
10% noose reduction on the adaptive gate. Activate input gate - noise reduction o.o%.
Delate the equalizers.
Today…not. They are good models, but there are superior models, and yes, i’ m not crazy…headrush Today (4.0) sounds better.
