Why does low passed sub bass have higher perceived loudness on particular notes?

[YoungCrocket]

The title is basically my question. While using a variety of different sub bass patches in massive, sine, triangle, square and what have you, I've noticed that certain notes will sound a lot louder than others. Sometimes it will be perceived loudness, coming from some weird resonance, and other times it will be perceived loudness and the actual levels will be higher as well. Why is this? There's only one thread I can find online that talks this subject and they never really get to the bottom of it. Like I mentioned before, I think that it has something to do with resonance but I'm not sure... If anybody creates sub bass in massive (Lp'd around 100hz) then you probably know what phenomena I'm describing. Any explanations or fixes would be much appreciated because this is really starting to bug me. I don't think it is any of my post fx or filter settings either because like I said, I've experienced it on multiple patches.

 

[rhythmgj]

Are you using any compression? Have you tried multi-band compression to tame just the egregious frequencies?

 

[The Funk Junkie]

The room you're in and the speakers you're using play a big part in it all. Certain frequency ranges can sound louder to the human ear then others. I find when playing with sub-bass sine waves in massive that the perceived loudness drops off really quickly below an A. As you start to go lower, your ear/brain can't process it. Frequencies below 30hz are just about undetectable to most people even if they're really loud (you might feel them, but not actually hear them)

 

[RockIn-Depth]

I must concur with the Funk Junkie. It is a mix of the room and of the resonant frequencies of the objects that your monitors are in contact with. I also like how you stated a "perceived" loudnes. I'm sure if you looked at your bass frequencies through a spectrograph it would confirm all of this. The loudness at certain frequencies is not coming from the source material but from the reaction of the frequencies to the room and the objects in it. Try to use baffling not just to pad a wall and stop reflections but to also eliminate any parallel walls. Parallel walls will cause standing waves in the room. All frequencies have a specific wave length and the distance between two parallel walls will create standing or reinforced waves at the frequencies that have wavelengths that are multiples or divisors of said frequencies. A quick example would be, if your room is 10 feet across and the walls are parallel, the standing waves or reinforced frequencies would be frequencies with wavelengths of 2 feet, 5 feet, 10, feet, 20 feet, and so on. (of course this is most likely going to translate more as inches than feet)

 

[localspace]

Apart from the circumstances of your room/speakers etc.. you do get those different amplitudes at different notes. That's normal, you can offset it with lower velocities and don't be afraid to squash the hell out of it using limiters, compressor/gates and especially saturators. Bringing some of those subtle harmonics and grit out, even just a bit, will help it stand out in the mix and register better on less than optimal (aka all) speakers.