If I upload an audio file, does Roblox use it as-is, or standardise it first?
If it standardises it, then there’s no reason for me to not convert the music to a lossless format (as long as it’s under 7MB), because it’s going to be compressed later so there’s no reason to have three lossy conversions instead of two (? -> MP3 -> OGG -> ? as opposed to ? -> MP3 -> WAV -> ?)
However, if audio is not standardised, then picking a max-quality WAV/OGG will impact load times, and I don’t know enough about the formats to know what the lowest quality is that almost perfectly replicates a 320kbs MP3.
I’m pretty sure it’s as-is. If I recall they even list a size limit on the file in the place where you upload. I haven’t noticed any loss in quality with my audios, but then again, I only do short or medium ones.
Whenever I edit audio on Audacity, I just simply export it as a MP3 and upload it on Roblox as such. I don’t hear a huge difference between WAV and MP3, but OGG is usually much less quality.
To add on, a properly exported MP3 is indistinguishable from a WAV or other lossless file of the same audio.
However, there’s many things to consider before you upload audio to Roblox:
How fast does the sound need to play? MP3s have a slight delay before the actual audio begins, whereas WAVs and OGGs do not. If the audio needs to be looped, MP3s aren’t the way to go.
How loud is the audio? What you’re referring to in the OP is called “compression”, and it basically means to reduce the dynamic range of a sound. Being a music producer, I mostly use compression to make the music louder, by cutting out frequencies you can’t hear as well as boosting those you can. In all audio, no matter what, compressing everything above 0 DB (decibels) is the best way to go, because anything above that is just going to sound loud and distorted. Compressing this means your audio won’t sound bad on sound systems besides yours, it will keep your audio sounding great for all the players that come across your game. KEEP IN MIND ROBLOX MODERATES AUDIO THAT IS TOO LOUD, SO SERIOUSLY CONSIDER DOING THIS.
Choosing the right bitrate for an MP3 (Or any other file type). Most online retailers sell MP3 music around 280kbs, which is considerably lower than the WAV files standard for CDs, around 1411kbs (Source is google xddd). Contrary to popular belief, there’s really no reason to have audio with a huge bitrate like that because you can’t hear the frequencies that are kept in WAV files. MP3s cut them out. I’ve gotten away with releasing music that’s only 192kbs MP3s, and it still sounds fine. I haven’t tried anything lower than that, so I’d recommend your MP3s (or whatever other file you’re using) to have a bitrate from 190-280 kbs. Over 280 is fine, but for your average player on Roblox who probably is playing on his phone or using trashy speakers, it might be overkill.
One small thing to note: if you need the audio to loop seamlessly, without a tiny pause or click, you must use the OGG format. MP3 files get just enough padding to keep them from looping seamlessly, even when the uncompressed audio is perfectly looped.
