Wondering if anyone can help me with this strange issue.
My imported sounds into Unreal are playing a few dB quieter compared to the raw assets outside of Unreal. We have even managed to find the hidden -3dB project-wide gain reduction in the WindowsEngine.ini file. But even with that set to 0dB, audio files are simply playing quieter that I’d expect. This is adding a bit of confusion when trying to understand the details of our loudness structures.
Hi,
The first thing that comes to mind is how Submixes work in Unreal.
Each Submix has Dry Level and Wet Level parameters. In Project Settings, the Master Submix description states that all sounds are routed through it. By default, the Dry Level is set to –96 dB, which effectively makes the sound quieter.
There are also MasterReverbSubmix and MasterEQSubmix. In a basic template project, sounds are routed through the EQ Submix by default, but not through the reverb (this is likely controlled by a send). The EQ Submix is connected to the Master Submix and is also set to –96 dB, which means the signal is effectively attenuated twice.
To check whether this is the source of the issue, try setting the Dry Level to 0 dB on both the Master Submix and the EQ Submix.
From what I’ve observed, the Master Submix and Reverb Submix always need valid values assigned in Project Settings. If you clear them and restart the project, they are automatically restored to their default settings. This suggests that simply removing them from the audio path is not a supported option.
This is just a guess, but it sounds very close to the issue you’re describing.
I hope this helps.
Best regards,
Gustaw
Is this a mono file?
@gustaw-kowalski apologies for the slow response, but that is exactly what’s causing it! Nice one. Our master submix shows a Dry at -60db by default, but when I bring it up to 0dB, it increases everything by 6dB (which is exactly what I was missing). I’m assuming it’s a visual bug?
@dan.reynolds I’m wondering what the intention of this Dry level is? I would’ve assumed Output volume and Dry volume would default at 0dB. Mono file btw
Hi,
Glad to help! I’m fairly certain this is not a visual bug, so I’ll try to explain it briefly.
Dry and Wet are two separate signals. If you simply sum them without compensation, the result will be louder – effectively doubling the perceived loudness. In the context of a Submix, that summed signal would represent the original loudness of 0 dB.
In most DAWs and audio plugins, this is handled automatically via gain compensation. For example:
Any value in between is automatically compensated so that the summed output remains at a consistent level (0 dB).
This is my understanding of how it works, and I hope I’ve explained it clearly.
Best regards,
Gustaw
It half makes sense to me.
I think the thing that is confusing is that in Unreal it’s not Dry and Wet that I was playing around with, but Dry and Output volume.
If we’re talking about the MASTER submix, you would think that going to -60dB (I don’t have -96, minimum is -60) on the DRY level would basically mute the sound, but it only goes down by 6dB. However, if you leave the DRY at full volume, and reduce the OUTPUT to -60dB, then the sound is muted. So that’s where it’s confusing, it doesn’t work like a Dry/Wet relationship.
The other thing that I find confusing is that let’s say I have a wav going through this chain of submixes SFX → 3D_World → MASTER. I can get the wav to play roughly (not exactly, off by about 0.2-0.3dB for some reason) the same volume as how it would play external to Unreal if I set the MASTER to both 0dB OUTPUT and 0dB DRY. However, the two lower submixes (SFX and 3D_World) are still set to 0dB OUTPUT and -60dB DRY. But if I increase one of those lower submixes to 0dB DRY then I increase the volume by another 6dB, and if I do it to the other lower submix, it then goes over 0dB and starts to distort simply playing the wav in the editor!
So this to me seems quite confusing. Why is it that I can set the DRY to -60dB on the master yet it’s still playing. What should be the default state to have wavs playing the same volume as externally? Simply setting OUTPUT and DRY at both 0dB “only” on the MASTER submix? Very confusing UX to be honest.
Would love to hear from a dev so I can try and better understand the concept behind it! @dan.reynolds
Hi,
I made some incorrect assumptions earlier and would like to clarify them. Unfortunately, I can’t edit my previous messages, so I hope this helps avoid any confusion.
Submixes work as intended.
A 0 dB Wet or Dry signal corresponds to the true input level of the sound. Setting both Dry and Wet to 0 dB (i.e. 100/100) results in the signal being summed and therefore becoming louder.
The only noteworthy behavior here seems to be a built-in optimization in Submixes. If a Submix has no effects assigned, the Wet signal is routed directly to the output, and the Wet controls have no effect. When effects are present, Dry and Wet behave as expected.
(Testing done in Unreal Engine 5.5.)
Regarding what Dan mentioned:
In Project Settings → Audio, there is a setting called Mono Channel Upmix Method. When it is set to Linear, a mono sound is upmixed to stereo by distributing the signal evenly across two channels (0.5 gain per channel). As a result, the total signal level is lower than a true stereo signal, which results in a -6 dB level reduction compared to stereo.
Taking all of this into account, I’m now testing with stereo sound assets, and the output is still -3 to -6 dB quieter than the original signal (depending on the metering method used).
Apologies for the earlier confusion.
Best regards,
Gustaw
