High Frequency bizzare potential phase issue

I have spent since about midnight last night here trying to work this out without having to post here and hassle you guys, but im at wits end…

Cubase 6.0.7 education version, build 634 - 32 bit, Win7 64bit, on mobo P35 DS3-R, with Focusrite Sapphire 6 USB (updated drivers on mobo + soundcard)

Have been using cubase on my laptop for couple of years and never noticed any issues. Formated my PC and installed the above setup. Wrote a track and was having trouble with high end content interfering, almost like a phasing issue but more like a distortion or artifact… eq’d the hell out of it but something was not right… ok so i ul it and noticed the wave display of my track on soundcloud showed the kick audio peaking and dipping in waves… had heard about this happening intentionally in some plugins to emulate variation in kicks etc (is this true?), and assumed if not it was just one of the many compression issues on soundcloud, but thought i would investigate given the high freq issues.

Chucked a spectrum analyser in the DAW with Bassizm kick track solo’d, and the high content was fading in and out every 4 beats or so - but im talking everything from about 1khz up to 10khz, which seemed a fair bit of frequency to be dropping in and out. Tried it again in guru sequencer with a range of different kicks… same thing, just diff frequency chunks dropping in and out depending on the content of the sample itself.

Kick i could almost handle, but my real problem lies in the fact that almost everything i feed into cubase on or off the beat in a 4/4 time signature (eg hats, synths for odd basslines etc) displays the same issues… i’ve included some waves i uploaded to soundcloud to show you what i mean > SoundCloud - Hear the world’s sounds + SoundCloud - Hear the world’s sounds

Test 2 demonstrates it the best, you can see the peaks and troughs of high frequency content on a solo’d percussion line, which is replicated exactly in the spectrum analyser in the DAW. Wish i could include a video as an eg, but if the percussion takes up 400 to 8khz say, beat one and two will hit normally, then its as if a lowpass filter is automatically sweeping down to cut down from 8 to 7khz on beat 3… 6khz on beat 4 etc then sweep back up to start again… that is what is creating the peak and trough waveforms.

I have tested tracks (ie solo’d with spectrum analyser on stereo out) both triggering from midi data and within sequencer Guru and groove agent one (w beat designer) - same results for both which indicates to me it’s definitely not a midi issue, nor isolated to one vst. This sent me in the direction of latency and the like so spent a while reading up here and in manual about Asio time useage and latency settings - ATU is sitting with 2/3rds headroom left which seems completely normal, no pops or clicks whatsoever outside of that. 10ms to 17ms buffer settings all work and make no diff to the problem.
I tried to activate direct monitoring to see if this zero latency setting could assist but it’s greyed out, which ive learnt means i need to route it in my console software - problem is Focusrite sapphire 6 soundcard doesnt have one! Not sure if this greying out is related. The only other soundcard issue that could be relevant is that my sapphire 6 in this pc has to use usb 1.1 rather than 2.0? That wouldnt affect just the high frequency then though… :S

In my hours of searching last night i even looked into issues relating to the specific mobo (why i included it above), but verified that the issue pertaining to latency spikes in the Gigabyte DS3R were not present after testing with DPC latency checker. Still tempted to do a bios flash if all else fails, but thats getting ahead of myself.

I was wondering if all this was normal at first, but the noticeable inconsistent artifacts it is producing combined with comments from many producer friends about the abnormality of of the waveform, makes me think not.

The only theory i can come up with is that there is some bizzare form of latency that is causing phasing issues that move in and out on a specific 4 beat patterns (enough time for it to build up?) - but again, why only high freq content?

I have barely slept trying to fix this so apologise if any of this is unclear or it is a simple problem ive overlooked. I have the latest realtek audio drivers from Gigabyte and for my saphire 6 audio card, and updated Cubase to the latest version as above, as soon as i had installed it.

Thanks heaps for your time people, hope to hear from you.

I am half hoping my friends and I are wrong in this is just normal DAW behavior, and my HFreq artifact/phase issue is just to do with lack of ability on my part. If so i would be still incredibly intrigued to know the nature and purpose of this sweeping effect.

I doubt it is normal DAW behaviour because

  • you did not have the problem on your laptop
  • i don’t have the problem either.

You have been testing your software and latencies.

My first thoughts are:

  1. Go take your project and take it to your producer friends. Try it out with them and listen to what happens.
  2. Go home again and borrow an audio interface from one of the aforementioned friends. Hook it up on your system and run the project again.

Maybe after this you can solve your puzzle? I know it’s a trial-and-error method but sometimes that is what works.
Good luck, hope to read what results you got.

have you verified youre using the correct asio drivers in cubase? Have you tried a different driver as a test?

it sounds like some kind of phasing issue, like you’ve somehow got two layers of the same thing playing at once

I’m sorry, but I’m not hearing it at all… :confused:
Not on my DAW setup atm, but every hit sounds the same as the other to me.

The wavy behaviour of the waveform on Soundcloud is not necesarily a sign of a truly different wave, I don’t know the logic behind it but I imagine it just takes a single sample or a short sample range and calculates the pixel height of the wave by that. You obviously don’t have enough pixels on your screen to display the true waveform. The amount of samples/the amount of pixels is most likely not a whole number, so you get a wavy pattern like this.

Now I could be all wrong, but I think it’s not to do with Cubase but with your hardware at the output stage, because I detect no anomalies in your uploaded samples.

awesome, thanks heaps for all the responses dudes.

im visiting a mates setup tomorrow, il check it all out there but he said the same thing about the test that he couldnt hear or see any probs on his end. im beginning to think it might be an issue with the eq display of fabfilter, and the artifacts/distortion/phasing in parts of the track are just due to bad sound design (ie competing high freqs) on my part.

ive tried 3 diff drivers and happened on all of them.

Its not soundcloud display that concerns me, that was just the initial trigger that made me investigate using fabfilter, which is where i observed the sweeping lpf effect. I can even hear it as i watch on the kick in my project, like the very high background noise moving up and down in tone, but im thinking ive just looked way too much into it and this is psycho-acoustics at play.

My mate just suggested then i do a phase test - so i put two of the same sample to trigger on same 4/4 beats in guru, inverted phase of one… resulted in silence for a 16 beat loop except for beat 3 which triggers a small noise down in the 100hz area, nowhere near the problem area in question. So really there cant be anything going on there, at least not in the vst/daw…

Il look/listen to it on his system tomorrow but honestly not expecting to find much, and if not im happy to keep using my ears to eq and ignore that aspect of the visual or find a new eq.

Really appreciate the suggestions people, il let you guys know if i can replicate the issue with the project at his place.

Cheers :slight_smile:

I’m pretty sure that’s what’s going on. I hear absolutely no difference in any of the percussion hits of test sound 2 (went through 2/3rds of it) - test 1 is a dead link btw. Try listening with your ears and not your eyes… :sunglasses:

totally agree re listening with ears not eyes, its become more an interest to see why fabfilter is misrepresenting the frequency content…

il post up these images to show you all what is happening then just let it go and focus on writing music :slight_smile: sorry if i wasted peoples time, appreciate all the responses folks!

  • lpf.zip is jpg image snapshots taken every beat or so in sequence over a 2 bar loop

  • kick waveform.jpg shows the waveforms of the kick over the loop

  • …(midi comparison).jpg shows a closeup of kick waveform with midi data above, strangely with sound before the midi note

nb All compressors and fx on solo channel and main output were disabled


lpf.zip (400 KB)

I concur- all hits sound identical.

Disregard the visual waveform on soundcloud! Aliasing in the graphics will make you see strange patterns that aren’t really there.

Identical to me too.

Aliasing in the graphics will make you see strange patterns that aren’t really there.

This same phenomenon has burned me as well in another industry where we analyze audio frequency waveforms. Beware the visual whe you’re working with audio.

Good advice folks, cheers. Interesting to hear of other people experiencing the same phenomena. Though i my case the waveform wasn’t the problem, rather the trigger that made me investigate/notice the variation in the fabfilter EQ in the DAW as shown in lpf.zip screenshots above… Could this aliasing issue in the graphics apply to eq’s within the DAW too?

One of the most important things i learned after reading and listening to peoples advice, was to trust your ears. I rarely waver on this issue, and actually started to eq without any kind of visual on which helped train my ears a great deal. However, i also realise my journey in music production will never really ‘end’, and i have a long way to go especially in terms of training my ears.
It is only because i consider myself relatively new to all this that the visual variation in frequency content concerned me enough to post here - i.e I was concerned i wouldn’t be able to ‘hear’ if the eq was misrepresenting frequencies in other areas. Seems to all be good though so time to let this one go methinks :smiley:

Anyways, really appreciate the feedback everyone :slight_smile: