I’m trying to master some stereo mixes and the bass is panned way to the right. How can I elegantly divide the track into two or more frequency bands, pan the bass frequencies to the center and recombine? I was thinking of duplicating the track, using a low and high pass filter set to the same frequency and working on it that way but it doesn’t seem like the best solution (phase issues?). Thanks
I know.
But the odds are he isn’t an experienced engineer. When Bob Katz does it it gets done right.
This sounds like a kludge no matter what you do, so I would look at going back to the source tracks.
Maybe, but introducing LF crosstalk like this is often done in mastering. If it’s done below about 150Hz, it makes no difference to the sound as the ears aren’t directional at those frequencies, and the advantages are that on playback it equalizes the amount of work done by the L and R power amplifiers (a lot of power goes into bass frequencies in some kinds of music) and reduces speaker distortion.
Ricardus: The mix is like that because I mixed it when I knew even less than I do now. The artist is me, but my opinions about pans have changed ;-).
Remixing is impossible because I deleted the original sessions somehow between moving tons of data from an old hard drive to a new one. So all I can do is mastering. I tried a few low/hi cut setups but wasn’t very happy with the results so for now I limited myself to narrowing the stereo spread a fair bit. It’s pretty tolerable now considering what I started with.
The M-S trick sounds interesting but I’ve finished the job now and I don’t feel up to revisiting it just yet. I’ll keep that in mind for the future. Thanks for all your help!
Well don’t do that! 
IIRC you are on Mixbus which should compensate for latency so long as the plugin reports it fine. I believe Ardour will do this as well. No need to duplicate the track persay, add another track, and set it to use the same playlist from the first track and it will accomplish it quickly.
Honestly any time you do frequency band dependant stuff like this you are likely to get some phase issues so it isn’t perfect compared to doing the mix right, but it is a start. The other thing to keep in mind is that below a certain frequency range we can’t localize sound as humans very well, so it is very likely that you are going to have to be much higher in frequency than you might expect and the trouble that brings.
Seablade
A good way to achieve this might be to use LADSPA matrix plugins for stereo to MS and MS to stereo. In between, apply LF cut to the S channel. You might need some LF boost to the M channel too, not sure how much but when you move the LF from one side to the centre you are going to have to make a balance judgement by ear anyway.
I think a better question is why is the mix like that? Did the artist or mix engineer want it that way? If so, why would you change it in mastering?
Can you ask them to remix?
This sounds like a kludge no matter what you do, so I would look at going back to the source tracks.
Another solution is to just sum everything to mono. That might actually be the least inelegant solution.
You can output your stereo mix to Jamin select the crossover point in the multiband compressor, and put the Low Band Stereo With slider (at the bottom) in -1, you will have low frecuencies in mono, this predure is fundamental in Vynil Mastering.