INFURIATING 'Rattling' on rendered recordings

mellotronworker wrote on 4/8/2019, 2:01 PM

Ladies and Gentlemen - can I ask for a bit of help with an issue that may or may not be a problem with Acid Pro?

I have a moody track which starts off with some gentle female choirs and a bass pulse underneath. Here is how it sounds inside Acid Pro during playback.

The problem starts when I render that to a WAV file. Here is how it sounds when played back as a WAV. You hear that rattling happening on the pulse? This something new - there have been no changes to hardware, no settings changes to Acid, yet this is happening now on most everything I am producing. What you are hearing is one example of it.

At first I figured that the 'pulse' was the issue, so I took it out, so that all that was left were the choirs. The problem persists. (Incidentally, the choir sounds are WAV files, the 'pulse' is from Trilogy VST)

So I thought to myself 'it's a VST thing' so I set all the VST tracks to 'freeze' and removed the VSTs from the project and dropped in the 'frozen' WAV files. This is what I found when I played it back. The problem is still there.

The effects and soft synth VSTs on the track are nothing new - I've had them for ages without any problem. In the case of this track there is only one VST soft synth playing, but even removing it doesn't remove the issue. Playing the track inside Acid is fine. Yet when I play back anything I render, I find this 'rattling' happens on every measure, and it is driving me crazy trying to find out what it is. I've even reset all Acid settings to the default, but it persists. The sound driver is ASIO and ACid is running happily on an Acer laptop as it has for ages, until now.

Does anyone have any ideas. Right now I am at a complete roadblock trying to produce anything. I've no idea if this is Acid or not, but it's deeply frustrating.

thanks!

Comments

CidBil wrote on 4/8/2019, 4:21 PM

@mellotronworker Hi, I just downloaded both the Acid pro version, and the first .wav you posted, loaded them into Multitrack Studio and A/B them. The only difference I noticed was the volume on the rendered .wav was lower than the original. The volume on both tracks though seemed extremely low. I didn't notice any abnormalities on the second track. HTH

mellotronworker wrote on 4/8/2019, 5:22 PM

@CidBil yes, it's quiet but I chose a quiet part of the mix to show it. Here is a louder version. That crackly 'rattling' is what I am referring to. I have no idea what is causing it.

CidBil wrote on 4/9/2019, 3:59 PM

@mellotronworker Well, I listened to both versions again today, this time through headphones, and I hear what you're talking about......very weird.....don't have a clue what that might be.......

johnebaker wrote on 4/10/2019, 5:00 AM

@mellotronworker

I suspect the issue may be the program switching the encoders to deal with the different audio formats / VST and effects

Try exporting the VST track as a wav file and bring this back into a duplicate of the project to replace the VST and export again.

HTH

John EB

mellotronworker wrote on 4/11/2019, 12:01 AM

@CidBil @johnebaker

Thanks to both of you with your suggestions. Problem solved - kind of.

All tracks were already rendered to WAV files, so VST synths were not the issue. In the end, I stripped off all the audio buses and played it back and the crackling vanished. The very odd thing is that taking the buses off one at a time (ie, removing A, then replacing it and removing B, etc) had no effect, but taking them all off did.

Some judicious notes about fade points and mix combinations later the buses were all restored and the project rendered silently. Two other tracks were similarly affected and were solved in the same way. Two of them had no crossover in their effects at all, yet they produced the same effect on rendering. I'd suspect my hardware were it not for the fact that it all played well inside AP8/64. I cannot even pin it to a rogue VST effect now.

So the issue has been solved for these projects, but this is something new I am always going to have to listen out for. The fact that it is only apparent once the project has been rendered to a WAV means I cannot even monitor it whilst mixing, which is pretty irritating.

The only thing that was clear was that the crackling was happening in time with the project tempo and that it got louder when the volume was pushed up, so it's coming through some channel somewhere, but you just cannot tell where.

Thanks again.

ebann wrote on 1/11/2021, 10:30 PM

This drove me nuts for a few days. I gave up on my song. Started with crackling and stuttering even though I have an i9 with 32gb ram and sys performance showed almost no load at all. Then song would render silent and Acid would lock up and I'd have to kill the process. Finally saw this and deleted the busses and it rendered fine. soooo I just saved the bus chains and opened them on each track then adjusted the db on the track +- whatever the opposite db of the bus to get the volume the same. Frustrating software. I made lots of great stuff on it over the decades but I think once I finish my bac catalog all new tunes will be in logic.

Former user wrote on 1/12/2021, 2:19 AM

One question, is there any side-chaining going on ?