Accuracy of Reason's waveform display in sequencer

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tobypearce
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04 Oct 2019

I'm wondering about how Reason displays the waveform in the sequencer.
This is a kick drum pattern. I bounced a single - i.e. one only - kick drum from redrum, duplicated across 8 bars then joined the pattern.
I'd expect each kick to look identical but in the screenshot below, they don't: there are small differences, mainly in the transient area.
Screenshot 2019-10-04 at 09.00.50.png
Screenshot 2019-10-04 at 09.00.50.png (292.11 KiB) Viewed 936 times
It's even more pronounced when you scroll out:
Screenshot 2019-10-04 at 09.04.34.png
Screenshot 2019-10-04 at 09.04.34.png (15.46 KiB) Viewed 936 times
This second view made me wonder if I'd done something wrong in duplicating, and made me feel uneasy when I don't *think* I needed to.

Can someone replicate this behaviour? Maybe I really have done something odd here.

There's no processing of any kind on this channel, but that shouldn't matter anyway because this is a display of the raw sample before processing, right?
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DougalDarkly
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04 Oct 2019

Deleted
Last edited by DougalDarkly on 09 Jan 2020, edited 1 time in total.

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buddard
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04 Oct 2019

tobypearce wrote:
04 Oct 2019
I'm wondering about how Reason displays the waveform in the sequencer.
This is a kick drum pattern. I bounced a single - i.e. one only - kick drum from redrum, duplicated across 8 bars then joined the pattern.
I'd expect each kick to look identical but in the screenshot below, they don't: there are small differences, mainly in the transient area.
Screenshot 2019-10-04 at 09.00.50.png

It's even more pronounced when you scroll out:
Screenshot 2019-10-04 at 09.04.34.png

This second view made me wonder if I'd done something wrong in duplicating, and made me feel uneasy when I don't *think* I needed to.

Can someone replicate this behaviour? Maybe I really have done something odd here.

There's no processing of any kind on this channel, but that shouldn't matter anyway because this is a display of the raw sample before processing, right?
The reason they look different is that your screen only has a few pixels of space to represent thousands of samples (at least 44100 per second)! If you have a 1920x1080 screen and draw 1 sample per pixel you would see about 43.5ms of audio assuming you could blow it up to full screen.
So unless the sample rate is perfectly divisible by the image resolution (which is very, very unlikely), each hit will not look exactly the same.

You should think of the waveform image more as a visual guide, i e to see where the transients are at, the basic shape etc, rather than a perfect representation of the sample data.

Mataya
Posts: 518
Joined: 03 May 2019

04 Oct 2019

buddard wrote:
04 Oct 2019
tobypearce wrote:
04 Oct 2019
I'm wondering about how Reason displays the waveform in the sequencer.
This is a kick drum pattern. I bounced a single - i.e. one only - kick drum from redrum, duplicated across 8 bars then joined the pattern.
I'd expect each kick to look identical but in the screenshot below, they don't: there are small differences, mainly in the transient area.
Screenshot 2019-10-04 at 09.00.50.png

It's even more pronounced when you scroll out:
Screenshot 2019-10-04 at 09.04.34.png

This second view made me wonder if I'd done something wrong in duplicating, and made me feel uneasy when I don't *think* I needed to.

Can someone replicate this behaviour? Maybe I really have done something odd here.

There's no processing of any kind on this channel, but that shouldn't matter anyway because this is a display of the raw sample before processing, right?
The reason they look different is that your screen only has a few pixels of space to represent thousands of samples (at least 44100 per second)! If you have a 1920x1080 screen and draw 1 sample per pixel you would see about 43.5ms of audio assuming you could blow it up to full screen.
So unless the sample rate is perfectly divisible by the image resolution (which is very, very unlikely), each hit will not look exactly the same.

You should think of the waveform image more as a visual guide, i e to see where the transients are at, the basic shape etc, rather than a perfect representation of the sample data.
REALLY? I did not know that. I'm a bit ashamed. Great piece of information. Tx

M

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artotaku
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04 Oct 2019

Not directly related to the OP´s question but if you render a Redrum clip of a kick sample the rendering process of the audio cuts away the start of the transient of the very first kick.

It depends on the kick sample material, though. I´ve the assumption that it only happens for kick samples with a very "early" transient in the first milliseconds.
This seems to be a bug to me.

The workaround is slide the waveform a bit to the right and cut the rendered audio in between (since it only happens on the first kick).

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tobypearce
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04 Oct 2019

Artotaku:
How about if you render a bar of 4 kick drums, and then use the 2nd kick drum in the pattern.
That's what I do, for just the reason you describe. Hopefully that works ok?
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One year - 52 tracks - Electronic Dance Music

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Loque
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04 Oct 2019

Stretching enabled?
Reason12, Win10

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artotaku
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04 Oct 2019

tobypearce wrote:
04 Oct 2019
Artotaku:
How about if you render a bar of 4 kick drums, and then use the 2nd kick drum in the pattern.
That's what I do, for just the reason you describe. Hopefully that works ok?
@Loque: Can´t reproduce it ATM, maybe I haven´t found the right kick sample where it has happened but I´ll keep an eye on stretching if it happens again (although I didn´t change any tempo before converting).

Anyway, the workaround is required as soon as you convert the audio clip to a rex file since the rex auto detection of the transient for the very first kick will not be correct and it´s audible. That´s why I slide the whole audio file a bit to the right and cut the clip on the 5th or 9th kick (as you mentioned) before converting it to rex.

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ShelLuser
Posts: 358
Joined: 25 Aug 2019

04 Oct 2019

DougalDarkly wrote:
04 Oct 2019
tobypearce wrote:
04 Oct 2019
I'd expect each kick to look identical
I know this is gonna sound like a stupid question (i've been on this forum for a little while now) but, do they sound OK? Why does it matter what they look like?
Not a stupid comment at all, in fact I couldn't agree more. Although visual representations definitely have their uses and overall value I also agree that Overly relying on visual feedback can easily lead to bad setups, so I think it's a good thing to get reminded about that every once in a while..

Heck... even the Props once specifically addressed this issue in one of their videos but unfortunately I can't find it right now.
--- :reason:

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guitfnky
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04 Oct 2019

if you want to put your mind at ease, make sure you’re only using a single sample, and the velocity is the same for each hit, and that everything is 100% quantized before you bounce to audio. next, duplicate the track. in the duplicate track, grab a section where the waveform appears different and (with snap on) drag it to a point where it looks different than the other track. then flip the phase on it and play it back. if it cancels, you’re good.
I write good music for good people

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tobypearce
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04 Oct 2019

You’re right - it’s not a big deal. The reason I asked isn’t because of ocd, it’s because the visuals do provide meaningful info. The way the waveform originally displayed (when I bounced the whole 8 bars) make me wonder if I’d rendered with a gradual hpf on the kick, which is something I do deploy time to time. So I had to go back in and check.
https://onetrackperweek.com
One year - 52 tracks - Electronic Dance Music

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