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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: (Evan) on January 08, 2011, 05:12:59 PM

Title: Weak low end when combining 4-channel H4n recordings
Post by: (Evan) on January 08, 2011, 05:12:59 PM
Hey guys. I've just been messing around with my new Zoom H4n and I have a question. I made some 4 channel test recordings using two cardioid and two omni condenser microphones. When combining the two stereo tracks into one stereo track without adjusting the levels between the two, for some reason the low end becomes very weak, almost non-existent. When listened to separately, the tracks are actually quite bass heavy. If I lower the gain on one of the tracks and allow the other to become more prominent, the bass slowly creeps back but I lose a lot of the detail from the mics that I lowered the gain on. I'm guessing this is a phasing issue? Any way to fix this problem without losing too much sound from one source? Thanks!
Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: hoserama on January 08, 2011, 05:53:32 PM
One of the interesting problems with the Zoom is latency issues.

Each feed will be off from the other by about 35-45 samples. So zoom into a high hat or something, line up the samples, and bingo it sounds better.

Lame I know, but stupid design flaw by Zoom.
Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: (Evan) on January 08, 2011, 06:04:03 PM
Thanks! Do you know if there are any drifting problems as well, or are the clocks synchronized?
Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: Shadow_7 on January 08, 2011, 08:31:38 PM
Sounds like a phase issue.  Could be some drift between the tracks.  Or it could be the arrival times based on mic spacing (or latency) could be different enough in timing to partially cancel each other out.  Check the waveform and see if they compliment each other (parallel) or mirror each other (phase cancellation).  It wont be perfectly that way as they're different mics in relatively different locations.  But there should be a majority average that leans one way or the other.  If it's clock related you might need to adjust the speed of one or more tracks.  Or time shift the tracks as needed to make them work.
Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: hoserama on January 09, 2011, 12:59:51 AM
Thanks! Do you know if there are any drifting problems as well, or are the clocks synchronized?

The clocks are synced, thank god. Or else it really would be a worthless recorder. Once you nudge the one in the right direction and align them, it's totally fine.

Try playing a studio song, split the signal into both inputs. You can hear the latency issues on the onboard mixer through the headphones.
Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: boyacrobat on January 09, 2011, 03:29:35 AM
try inversing  one of the 2 feeds
against the other
have your ears fully alert and listen

make sure you set your daw for point millisecond increments when offsetting samples
very important for narrowing inn

also try each left and right ch on there own as opposed to both ch together when inversing ch
somewhere in that set up is your problem me think

if there both bass heavy on there own
you should be good for a brilliant lock
from start to finish without phasing issues
if rec using multi input multitrack rec

also try rolling off the arse end of one or both feeds
i have had this type of problem on my matrix adventures
using multitracks and found i config lefts and rights wrong
on set up on the night
inversing ch together and on there own i got it liquid again

also have had arrival issues and learnt to not spread as wide
when going for real time matrixing .


g



Title: Re: Weak low end when combining 4-channel H4n recordings
Post by: TimeBandit on April 10, 2011, 07:22:08 AM
it´s phase deletion issue me thinking. try to get the files into DAW software with a plugin to invert phase.

on way is inverting phase on ONE of the both stereo channels and use a bit of EQ to sort the bass area out.