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Question about tracking two bass lines at same time.

O

olaff421

Sep 29, 2006
627
3
Murfreesboro TN
www.44vegas.com
#1
So all of the recording I've been doing lately has been in my drummer's bonus room studio. The way I've tried recording is to run a DI before and after my pedalboard to get the clean and wet sound going. However, when we play the tracks, both before and after recording, the sound drops way down. If we solo either channel it sounds fine, it only does this when we play both at the same time. This happens with or without effects going.

He said something about the fact that both tracks are playing the same low frequency that they are cancelling each other out. This doesn't really sit well with me. If that's true then actually recording a biamped bass track would be impossible, and why can guitars have multiple layers of the same thing?

Is it just his equipment? I can't give you names of anything he has, so not much help. I wish I could remember the program he uses, but my mind just went blank when I tried to type it.

Thanks for any advice or help with this.
 
#2
Sounds like it maybe a cancelation issue of some sort.
Maybe that ever so slight delay of your signal through you pedal board when mixed with the dry signal is causing a phase issue.

Try the DI before your pedal board alone, then take that recorded signal and "re-amp" it through your pedal board (sending the recorded signal back through your pedals).
 
#3
Probably what is happening, I think, it that there is a latency, slight perhaps, in the signal going through the pedal board, thus waves in the two tracks are are essentially canceling eachother out, just like two Mic picking up the signal from the same sound source. If you can zoom in on the two tracks in your DAW and phyically aling them so that the peaks are matching up with peaks. Your signal sould get louder.
 
#5
Hmm, so even the ever so slight delay from the pedals can cause phase problems. Never knew. We will be hitting the studio again coming up shortly, so this is all good info. Sounds like most of the fixes will be done in post, so the drummer and I will be putting a few extra miuntes, hours, whatever into it.

Thanks for the help guys!

P.S. Just thought about something right after I hit 'save.' If I'm getting latency from the pedal signal, would it be possible to somehow adjust the latency, in the recording program, for the pre-DI? I'm not too sure about the interface for his program, but is there a minute adjustment on most, or is it usually just incrimental (5, 10, 15 msec etc.)?
 
#7
Yes, you likely have some kind of phase cancellation. You can certainly try reversing the phase of one of the tracks, but may or may not help - it depends on how out of phase you are. Reversing the phase moves the phase 180 degrees. If you are 180 degress out of phase you will hear big difference, but if you are a different amount out you may hear less of a difference. It's also possible you may get more cancellation.

I actually align my tracks by hand in my DAW - zooming in and moving the tracks so the the start in the exact same spot. It's a bit time consuming, but fool proof!

Good luck!
 
#8
Olaff-

I also had my first brush with phase angle issues recently. In the process of Googling solutions I read about an interesting new box from Radial. Maybe it would help you, or maybe not:

Invalid Link Removed

Good luck. My solution will probably be to experiment with mic placement and distance.
 
#9
Yes, agreed, as everyone points out, that it's a phase issue. Many times, buffers on outboard effects flop the signal 180, so in the software look for a "phase" button to flip this around on one of the tracks.

I would recommend recording straight in, then adding wetness on a mix down. If you need wetness to get in the groove, then add the effect on the monitor send. Later add it to the track.
 
#11
A number of pedals change the phase of the signal going through them - if the signal passing through that pedal is all your hearing, it's not a problem (theoretically, at least - some folks seem to be able hear absolute phase). In any case, fixing it is a wee bit more involved than simply lining up the two signals.

Zoom in on the beginning of a note - almost to the point that individual samples are visible, and look at the wave forms from both tracks. I bet that you'll notice that one goes up and one goes down (because they're out of phase with each other). if that's the case, you'll have to use something (either a plug-in or, in pro tools at least, an Audio Suite function) to reverse the phase on one of those tracks. That should fix your problem.

And after I wrote this, I realized that seamonkey wrote the same thing. Sorry for the redundancy.
 
#12
Do not do what one post above said "easy fix is to... pan them L/R to get that Steve Swallow sound", that will just give you a completely mono incompatible mix. Either use a sample delay plugin to compansate for the mismatch of waveforms (try moving with increments of 1ms until the sound gels).
The reason this problem is much more pronounced with bass & low frequency sounds is that bass notes are much less complex than guitar notes. They are much closer to a sine wave & with the long wavelengths, make it much more likely for an inverted phase problem.
Another solution would be to use one of your recorded tracks for the bottom end, & the other for the mid/top end. So for instance, take your dry signal & filter off the high freq's & EQ to get the level of bottom end you desire. Then take your wet signal & filter off frequencies below 250hz, for instance, & use this to add the definition & presence to the bassline. This will remove the problem of phase as the two signals will not be sharing the same frequencies & there is therefor no corresponding waveforms present to cancel eachother out.
 

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