Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
Comments
What frequency is your LFO operating at?
There's something very odd about that scope view. I wouldn't expect narrow bands of aliasing in that way.
Cannot tell.
Just copied that patch and modified it.
Can later try to upload, if I still have it.
I just tried to change the volume around once a second or so, you can see that in the picture.
But as someone wrote, a musical App may not be the best way to create such tones.
Can you upload your patch so that I can take a look?
Audulus should be pretty good for this.
https://www.dropbox.com/s/fqhqaqz681lp4w9/Auto Knob Sine Sweep 3.audulus?dl=0
or
https://www.dropbox.com/s/fqhqaqz681lp4w9/Auto Knob Sine Sweep 3.audulus?dl=1
Please try, I disconnect the "1" from "Amp" and re-added the second LFO.
Are the two links, links to the same file?
Here is my sweep generator for Audulus:
Yes, same file, once dl=0 once dl=1 as I sometimes have problems with downloading from YT.
My Files App is hanging again, cannot access AudioShare from Audulus, where I unzipped your file.
It's so frustrating.
EDIT: Got it on the other iPad!
That's an impressive patch!!!!
Many, many thanks!
Going to play around with that.
@tja: I am still a bit unclear about which case resulted in aliasing and which case gave you a aliasing?
Which case resulted in aliasing for you?
Which case was clean?
I am curious if you get clean results with the sweep patch I posted.
For anyone without audulus here is a link to a 20Hz-22.5kHz sweep over 20 seconds. You will notice that the amplitude is slightly lower at the very beginning due to an Audulus quirk that I need to look into:
https://www.dropbox.com/s/gj1vdcj56yjc1ig/AudulusSweep 20to22500.wav?dl=0
The clean version was just a Sine Wave swipe from 0 to 22050 Hz and back to zero, without any modification of the volume ("Amp" set to 1).
Maybe you can try this too, to see if this removes that quirk you mentioned.
The aliased version version has the second LFO modulating the volume ("Amp" connected to the second LFO)
Not sure why we misunderstand here - this is just what I uploaded to Dropbox.
More clear now?
I will try around with your patch, even as it looks intimidating once opened
Question: How to set the time? The values does not directly correspond to the number of seconds
Now...
Here is something wrong!
Cannot upload the Screenshot, too large.
This file is clearly destroyed and is not the same what I here in AudioShare!
Going to check this
Downsized:
I have no explanation.
Initially, I produce a 24 Bit file in AUM, but I retried with 16 Bit and the result is the same:
In Audulus, AUM or AudioShare the swipe is totally clean, but in SpectrumView you can here the aliases in the upper range.
SpectrumView is doing something wrong, it seems.
Going to try around
In my patch, the time is set with the duration knob. You don't need to go inside of the patch to set anything. All the controls you need are visible when you open it. Of course, you are welcome to study what is inside.
When you open the file I posted you should see minimum and maximum Hz knobs which let you set the range of the sweep. The duration knob sets the time that the sweep takes. Turning sweep off, lets you use it as a straight sine generator with the pitch set by the pitch knob.
I repeated this on the other iPad, with the same result.
I made sure that I recorded at 44.1 kHz and 16 Bit.
I even did not trim in AudioShare to make sure that I use the original file from AUM.
No idea
We do have a little communication problem.
I did read what you wrote in the patch and totally understood, so not additional explanation needed for this.
What I did not understand is, how the value of the duration knob relates to the duration in seconds.
They do clearly differ. You cannot enter the seconds!
OK, this is clearly a bug in SpectrumView!
I shared the file from within SpectrumView back to AudioShare, and there, it plays like the original!
I also own RTA Ultra from 4 Pockets, but this thing cannot load files an you cannot share files to it - pretty useless...
@tja: are you saying that when the knob duration readout says 20 seconds, the sweep is taking a different amount of time?
Or are you saying that the knob value is different from what is displayed? If this is what you mean that is because I follow the preferred Audulus convention that knob values go from 0 to 1 and are scaled using an expression to the desired range.
More or less the second.
I wanted to set the duration to 22 seconds, but the values are not seconds.
You cannot use the Knob for that... it's wayyyyy to inaccurate! Old and big problem of many IOS App. We had a topic about that.
But this is not 0 to 1, as about 22 seconds can be reached with a value of around 1.44
Entering seconds would be better, I think.
Maybe I can tweak it. Have zero Audulus experience
EDIT: No way. After opening your patch, I clearly understand nothing
There are a couple of ways to accomplish what you want.
The "most correct" way would be to do the following:
An easier way to accomplish what you want is to:
You could also change the expression node that is currently x*20 to be just the number that you want the duration to be be if you don't want to set it with a knob. For instance, you could change it from "x * 20" (which means x times 20) to "22.0" if you want the duration to be 22 seconds precisely.
Ahh, many thanks!
Will try around
@tja: after a little experimenting, I think that SpectrumView has a bug that causes its analysis to show aliasing if the signal amplitude is above about -3 db. This may explain the results you saw when sweeping the amplitude.
I reworked my Audulus patch to use the raw-osc node and fed 1 to the amplitude. SpectrumView shows all kinds of extra harmonics and aliasing in that file -- but in the izotope RX7 demo it looks totally clean.
Applying a little gain reduction (-2db) in Twisted Wave results in the file looking clean in SpectrumView. So, I think SpectrumView isn't accurate in some amplitude ranges. Darn it.
Oh, very Interesting!
I already wrote to the developer, but if course without this information.
Will add it...
Also, will try to repeat my test with some gain reduction!
Many thanks
EDIT: It does not only show artifacts! They can be heard!
The only alternative to SpectrumView Plus seems to be this:
https://itunes.apple.com/us/app/audio-analyzer/id681184981?mt=8
This can also handle files and does not require a subscription.
Sadly, it also cannot be hosted and used for live audio (beside microphone or audio interface).
There is a market for such an App!!!
I wrote to the developer, they reproduced this as bug and will try to fix it.
I also mentioned to them, they should be adding a way to host their App in a DAW, AUM or AudioBus and quoted this forum as a contact.
I've started a new topic where we can talk more about this topic without derailing this conversation: https://forum.audiob.us/discussion/33520/audio-analysis-tips-tricks-and-thoughts
I will post some discoveries about SpectrumView and Audulus that you may find interesting.
To create a developer account, you either have a registered company, or they make you use your own name, its that simple, not all developers can afford to register a company and all that that involves, just sothe ten people who buy their app can search it easier.
Thanks for explanation, @Turntablist