Zoom Gear & Home Recording Forum

Hey, i'm new here and quite new to the H4.
In stereo mode, while using the onboard mics, my meter always registers slightly higher on the left side. (unless they pick up a right side dominant signal)
I've transfered the files into Sonar, who's meters concur.
This is my second unit (the first had black goo in the rec button's recess) and the first one also exhibited the misbalance.
Has anyone here experienced this?

I've done several stereo recordings. No obvious L-R level difference when listening, and waveform analysis shows the L-R levels matching within a fraction of a dB - except when there are loud sounds on one side or the other.

I actually noticed this a couple of times with mine as well, I always figured maybe I didn't have the unit square to what I was recording. In any case, I haven't really checked it out more than listening, and I couldn't ascertain any audible imbalance so I chalked it up to somewhat inaccurate meters at times...

Thanks for the replies.
Yes, i actually couldn't hear a misbalance but there's definitely something going on here.
I would really appreciate some more replies on this matter so that i can work out whether or not this is the case with the majority of units as i don't want to exchange this one if there's no point in doing so.

A few times, I've had one channel display higher than the other. But on mine, that's always been because I had inadvertantly at some point adjusted one channel independently at some point. Have you tried using cursor to separate the line level setting to set the levels for each independently and then resetting it to the joint mode?

I can't be much more specific than that, but L and R are independently adjustable when using the internal mics in stereo mode, so I recommend setting them to be even and then rejoining the control. You may find that you never see the problem again. Hope that makes sense.


Brian

Hey Brian,
thanks! i didn't know this was possible in stereo mode.
I'll give it a try.

Brian - I've tried to do this and checked the manual but found no way to independantly set the channel levels for the internal mic.
I can do this for line 1 and 2 but as soon as i exit the level setting screen they both default back to 100 so this cannot affect the internal mic's balance anyway.
Am i missing something?

Sorry. I see I'm wrong. The manual states that when using the onboard mics, the two recording levels are always linked. Page 32.

My memory must be failing me. I could have sworn I was setting up one of my first recording efforts and one mic was showing significantly higher than the other in a talkative crowd, and that I eventually found I had to lower that channel and did. It must have been a dream, though.

I've never used external mics, but apparently they must be used in order to have independent gain control for live stereo recording.

Brian

There is a kludge to work around this. In 4 track mode, record in linked stereo. Then go to the mixdown screen. Here you can set the L-R balance (in addition to setting the level).

Unfortunately it's the same situation in four track mode, so, when you switch back to internal mic mode any balancing adjustments you made in line mode are lost.
So now i need to walk around with a battery pack and two external mics to get this thing working properly. I'm not sure i can fit all of that in a pocket and hold it with one hand.

Not sure I understand you. First, record in stereo in 4 track mode, using the internal mics (or external, doesn't matter). Then, after recording, you can set the L-R balance using the mixer.

The drawback is you're setting levels after the fact, not while recording. But hey, it's just a workaround.

BTW, why not set the L-R balance in CuBase, Adobe or whatever app you use for post processing?

This has become a little more complicated and rules out the balancing "quick fix."
I placed a timer, emitting a high frequency beep, dead centre of the mics and found the meters to be perfectly balanced. (i tried this as i had noticed the meters were behaving correctly every time the mics heard sounds which only contained high frequency content)
I'm going to do some detailed tests with descending sine tones to try to determine where the right side's deficiency begins.

I posted this on another topic, but makes more sense here.

This is the test I did. For a sound source I used my Qwiktime quartz metronome that has an A440 tuning note. In stereo mode with the h4 about 1" from a glass table, I placed the note generator on the table inline to the h4 mikes. (By eyesight, trying to accoustically balance around the opening to the little speaker). The level meters seemed to be right on.

I then moved the metronome (sliding it across the glass) left and right across the glass. As it approached 20 - 40 degrees off axis, you could see a change in the left/right levels. And those seemed to me to be in the correct direction for the movement. That is, as I moved it left, the left level lowered. I think that is what I would expect as it getting much more off axis to the left mike (that is pointing right).

It would be interesting to see this same test at different frequencies, but I don't have a tunable audio frequency generator.

Thanks for doing that JL.
I do suspect the metronome's frequency is around about the same as that of my timer so i wouldn't expect the fault to exhibit with this test.

The human voice serves quite well as a tunable audio frequency generator.

My tests were not as scientific as yours but the end result was the same: the H4 mics are well balanced L-R - any imbalance that might exist is pretty small - a fraction of 1 dB - nothing noticeable.

It's worth mentioning that the ear/brain uses phase as well as loudness for directionality. A sound coming from the R, hits the R ear about half a millisecond before the L ear. The brain (subconsciously) detects this slight delay and interprets it as a directional cue. So to measure stereo separation and balance accurately, it would also be useful to measure phase.