I just read about this technique which apparently Jacquire King uses and has been talked about in various videos online. 
 
Basically you solo the kick, put the fader at 0dB, slap a VU meter across the master bus, start playback and adjust the input gain on the VU meter until the needle is just kissing -3dB. Next you solo the bass too so that the kick and bass are playing together. Then you adjust the level of the bass so that the VU needle is just kissing 0dB when they play together. The idea being that an increase of 3dB is equivalent to doubling the volume of the kick, so you've effectively made the level of the bass identical with the kick. You can then adjust the kick fader until it's peaking where you want it for your mix, making sure you link the kick fader to the bass fader so that they move in tandem and keep the same relative level. 
 
Does anyone have any experience of doing this? How does it work out in general? 

In theory it should work perfectly as long as this is what you are going for.  Ive done this a few times and found that it will get you in the ballpark.
 
I believe the theory behind it is if you take a track ... any track ... and duplicate it(same volume as the original), then your output increases 3db.  This is true no matter the source material or no matter how loud/quiet it is. Two duplicate waves at the same volume adds 3db.  I might be slightly wrong on the science, but the basic premise of what is going on is in there somewhere lol
 
so using that theory, if your kick is at -3, and adding in the bass pushes it to 0(3 db gain), then the bass should be the same volume level as the kick at this point(in order to have created a 3db gain).
 
Still, youd want to hear it in the context of the song, and Id trust your ears before I trusted the trick.
 
If you do it and the bass sounds too loud or too quiet or whatever...  dont feel like you did something wrong or dont feel the need to keep it there because 'science' presents a theory that says they are at the same level.
 
I would suggest this trick to somebody struggling with figuring out where the bass should go in the mix.  If you always find that you think its good til you audition the track somewhere, and in your car or wherever you find the bass is super overbearing....  or you do the exact opposite and overcorrect and have the bass too quiet......an approach like this will help you in getting the level of the bass reasonably close to the ballpark.
 
If you know what you are going for and consistently produce a result that you like, then definitely I'd let your ears be the final judge.
 
 
 
 

TBH never bothered with that approach.
I think it really depends on what your mixing.
A big wompy kick and slow bass line don't work for a lot of my stuff so giving them that kind of sonic real estate can be detrimental.  
 
 
 
 
 

But then you hear that it takes 10 violins to double the perceived sound of just 1 violin. So there seems to be some voodoo/misapplication of physics here somewhere.

Unless I'm missing something, that would only work if the bass note was the same as the kick frequency.  Once the bass line starts moving the balance would be void  - right?  
 
Again unless I'm not getting it, not really sure why you'd want the bass at 0dB
 
Just my .02

fret_man
But then you hear that it takes 10 violins to double the perceived sound of just 1 violin. So there seems to be some voodoo/misapplication of physics here somewhere.

It's based on the fact that if you duplicate a track and play them together, the output rises by 3dB.

fret_man
But then you hear that it takes 10 violins to double the perceived sound of just 1 violin. So there seems to be some voodoo/misapplication of physics here somewhere.

That's so 8 more volinists get paid.  :-)
 
A sound wave is a sound wave whether it comes from a violin, a kick drum, a bass or vocal.

conklin
Unless I'm missing something, that would only work if the bass note was the same as the kick frequency.  Once the bass line starts moving the balance would be void  - right?  
 
Again unless I'm not getting it, not really sure why you'd want the bass at 0dB
 
Just my .02

This isn't an EQ balancing trick, it's just to get the levels of bass and kick in the ballpark relative to each other. I presume you'd do it after EQ'ing. I think where it could be helpful is in getting a good level balance if your monitoring situation isn't the best. And it wouldn't be limited to getting the bass and kick at exactly the same level - even if you want one to be stronger than the other, at least by balancing their levels you have a good starting point from which to bring one above the other. This would, I presume, help prevent situations in which you play your mix elsewhere and either the kick or the bass sounds wildly out.

conklin
Unless I'm missing something, that would only work if the bass note was the same as the kick frequency.  Once the bass line starts moving the balance would be void  - right?  
 
Again unless I'm not getting it, not really sure why you'd want the bass at 0dB
 
Just my .02

you wouldnt leave it at zero.  This is simply because the meter is easy to read at zero.
 
If your kick was say -15, and you were adding in the bass trying to make the level with the two tracks end up at -12....  its just a lot harder to read such a small window on the meter is all.
 
once you set it and establish the relationship between the two....youd simply maintain that relationship even if you have to turn it down.
 
as far as frequency goes.....  this is more about volume.  and if you think of the bass signal, typically its going to be pretty compressed and consistent.  you arent going to have any particular notes that are way louder than others.  at least you shouldn't.  So more or less it'll be pretty consistent.  Enough to get a ballpark.    And if you do have certain notes that are waaay louder in volume than others....  you should compress until you dont ;)

I've used it a few times and it does exactly what others have said, it gets you in the ballpark. It's a nice starting point to reference.