Hey guys,

I've just got a few basic questions about the H4n. I recently completed a short film using the Zoom H4n, and a Rode NTG 2. I recorded sound in the default "Stereo" mode on the Zoom. I had the Rode plugged into input 1, so it recorded the signal into the left channel. I assumed this would be fine, since I could just pan it to center later. Well I did, but the problem is that I also recorded a low level of hiss in the right channel, that is apparent in the mix. I've been working on removing the hiss, but I wanted to ask, for the sake of future projects, what mode do you guys record in?

Since discovering this problem (should have discovered it before I even shot, but I was rushed and didn't think I needed to test it out more), I've experimented in MTR mode which lets you just record into one channel, as opposed to stereo where you are required to record both right and left channels at once. This does not record the hiss.

I like the set up of stereo mode better. When you hit stop, it ends that file and makes a one the next time you hit record (ie STE 001, STE 002). On MTR mode, it seems to keep all takes in one long continuous file. But obviously recording a cleaner sound is top priority.

How are you guys doing it? Thanks!

Scott

You've recorded with the same settings I'd use on the H4n.

In post, I would delete the right channel, the left channel would become a mono track. Depending on your editing software, this should be not too hard, hopefully.

Some NLEs call this channel conversion | source to use | left channel only. What are you editing with?

This is the sort of process that also allows you to use the right ch. of your H4n for a lav - in that case, you would have duplicate tracks in post, one of them mono-left-only, and one mono-right-only.

Make sure you don't have Mono Mix activated in the Zoom's input menu.

What software did you use to edit? You should have been able to completely ignore anything on the right channel and not have any influence on the sound by only using one mic. UNLESS YOU HAD MONO MIX ACTIVATED.

I have in the past recorded only one channel in stereo mode when I have only one source to record on my H4n. Never had any problem doing this. I use Sony Vegas and you can choose "Left Only" or "Right Only" (and several other choices) as a channel selection for any piece of audio.

The NTG-2 has moderate output, and the H4n preamps aren't very quiet. If you were pushing the recording level up, you may also be getting noise that way unless you can say for sure that it wasn't there while monitoring during recording.

In the meantime, to correct what you have, use an audio editor (I used the free Audacity for a quick test). Open your Zoom file and in that program "pan left (all the way). In the test I ran this left the right channel totally "quiet", no matter how much I ran the gain up in Audacity or cranked up the gain to my headsets I could hear no "hiss" or noise.

Export to a WAV file and you can then either bring it into your NLE and pan center there, or open the exported WAV file in Audacity and pan center there. I usually run the recording level on my ZoomH2 fairly low and adjust the level to where I want it in Audacity.

Hope this helps get you out of your current situation.

In Premiere you would simply use the "Fill Left" effect to replace the hiss on the right channel with the audio from the left.

Hey guys,

Thank you for all the responses so far, they've been extremely helpful. Here is what I've learned so far.

-Checked my Zoom and Mono Mix WAS NOT ON, and Jay said it shouldn't be. I know that we recorded in stereo mode, but I'm concerned because when I mute the right track and hear only the left channel (where the audio is), it sounds better but not perfect. There is still some hiss. I also completely deleted the right track, duplicated the left track, panned one all the way left and the other all the way right (to simulate stereo), but it still produces a little bit of hiss that feels unwanted.

-On the other hand, if I record in MTR mode, and have the Rode NTG 2 going into track one, all it records is the signal from the NTG 2 onto one mono track (so it does not record a blank hiss channel like it would in stereo mode). When I play this track in comparison with the original stereo file (after deleting the right channel hiss track), the MTR track still sounds a little clearer. Does this mean that the stuff I recorded in stereo actually has the hiss baked into the good left track? I sure hope not. I had a friend run a test in Pro Tools to remove the hiss from the left track. He was able to do so with compression, EQ, and a noise gate, but it negatively effected the noise quality, making it sound almost robotic (Similar to if you run a heavily distorted guitar through a noise gate to remove the hum/hiss. It just sounds unnatural. Goes from completely silent to very loud).

-I'm editing in Final Cut, do you guys know of a good way to use only the left channel in Final Cut? Or is what I've done by deleting the right channel and duplicating the left essentially the same thing you have done in Premiere when you select "Fill Left?"

Also, could it be that I'm just recording the audio at too hot of a level? Sometimes I record with Mic input between 90 and a 100, but I always thought it was best to record it as loud as you can without peaking out. I know it's better to get the mic closer to the subject rather than to just turn up with input level, but a lot of times I would have the mic no more than 1 foot away, and still have to crank up the input level, because the actor was whisphering or talking quiet. Do you think the high input level is to blame? If so, should I plan on keeping it lower in the future (say around 75) and just bring it up a lot in post?

Scott

Thanks guys.

Scott

Hey guys, I'm still trying to solve this problem. When I delete the right channel, it sounds slightly better, but there is still some unwanted hiss in the left channel too. My best guess is that since I recorded it with the mic input level between 90 and 100 that the preamps on the Zoom started making noise. I posted an audio sample below so you can hear it, as well as a screen shot of my ProTools session so you can see what it looks like. Keep in mind, that on normal computer speakers, the hiss may not sound like a big deal, but on studio monitors and on my home theatre speakers it becomes really annoying.

The audio sample has the same line of dialogue twice in a row. The first time, it is with the right channel deleted, so all you are hearing is the left channel where the NTG2 was recording to. The second time you hear the dialogue, it is the left channel, as well as a right blank channel. The right blank channel contains a little bit of noise, but it is almost hard to notice a difference between that, and the first time the audio played. After the second time, I included a little bit of that right channel hiss by itself, just so you can hear what it sounds like alone (so to be clear, the first audio portion + the third audio portion = the second audio portion). That may be more confusion, so I that's why I included the screen shot.

Screenshot:
http://i4.photobucket.com/albums/y104/phase27/Screenshot2010-10-11at111938PM.png

Download Audio Sample:
https://www.yousendit.com/dl?phi_action=app/orchestrateDownload&rurl=https%253A%252F%252Fwww.yousendit.com%252Ftransfer.php%253Faction%253Dbatch_download%2526batch_ id%253DWTNKanZpd0kwZ252Wmc9PQ

Anyways, let me know if you guys can figure out why the left track still contains a bit of unwanted noise. Deleting the right track from it doesn't seem to help much. Did I just record it too hot? If so, what can I do to remove the noise?

Scott

What voltage phantom power does the Rode require? If you are having to gain up get get some sound in you might need to consider feeding the H4n from a good field mixer which phantom powers the mic. Take notice of others more wise in the sound craft than I who respond to this.

Bob,

Any input is welcome and helpful. The NTG 2 actually can run either on AA battery, or Phantom power. I've always just used an AA battery.

Hey guys,

-I'm editing in Final Cut, do you guys know of a good way to use only the left channel in Final Cut? Or is what I've done by deleting the right channel and duplicating the left essentially the same thing you have done in Premiere when you select "Fill Left?"

Scott
Thanks guys.


I don't personally use FCP, but on my last post-audio project. I was asked to assist an editor on some rough-cut audio issues.

FCP 7, See Page 682, "Chapter 43, Audio Editing Basics"

Essentially what you want to do is, change the (recorded) stereo pair to dual-mono, (unlinked) then disable or remove the unwanted track from the timeline. confirm the desired track is panned to center.
You can also set this in the capture stage in FCP.
I know less than nothing about Premiere, but whatever gets you there.

Rick,

Thanks for the info. I didn't know exactly how to do it on FCP, but I was able to do that on ProTools. The problem is still apparent in the left channel, so now my problem is that I'm trying to figure out which filters to apply to remove audio hiss from that left channel. An audio sample can be heard above to hear what I'm describing. I'm also trying to figure out why there is a hiss in the first place. My guess is that the input level was too high, but so far no one has been able to confirm or deny if that would make a problem. Are the Zoom preamps so noisy that it would add noise when cranked up to 100?

Here are the filters available to me in Final Cut.

http://i4.photobucket.com/albums/y104/phase27/Screenshot2010-10-12at124851PM.png

http://i4.photobucket.com/albums/y104/phase27/Screenshot2010-10-12at124832PM.png

Scott

"My guess is that the input level was too high"
-- This would only make a difference if distortion was an issue. If you recorded at a lower level, you would only have to raise the level in post to compensate; getting basically the same result, but probably more so, from a even higher noise floor.

"Are the Zoom preamps so noisy that it would add noise when cranked up to 100?"
-- I have never used an H4n, but would expect the mic-pre's to be rather noisy on a recorder (or mixer) in that price range.

I have listened to your sample file and don't hear any serious problems though (at least for non-feature film work) Are you monitoring at ridiculously high volume levels and/or have monitor speakers with an abnormal frequency response?
That said, noise reduction is about the only effective way to attenuate hiss without affecting the 'good' audio. However for dialog only tracks it's not uncommon to roll off the high-end out starting at around 10kHz with an EQ. Look for a 'low-pass' or 'hi-cut' filter pre-set or set it yo'self.

Rick,

Thanks for the information, that looks like it will really help. I will try some of those filters and see what I can do.

What volume were you listening to the sample at? Like I said, when played through my AKG K240, the hiss isn't very noticeable, but when I play it back on a Bose surround sound system it is pretty obvious. Try listening at a higher volume if possible, I'm sure you'll hear it. This isn't for a feature film, but it is a 20 minute short film that has potential to get some attention. It has a couple of known actors in it, so I'm really trying to make the sound as best as possible.

Scott

Has any one tried listening to it at a higher volume to see if you think it's bad? It sounds like there is too much noise to me, let me know if you hear it.

Scott

Scott,

I have the equipment you are working with. So, I conducted a little experiment. Check out this post:
http://www.dvinfo.net/forum/all-things-audio/486138-improving-h4n-snr-juicedlink-low-noise-preamp.html

-R

Hi Scott,
I listened on some HPs; AKG-240 ,Sony 7506 and Fostex T-20s and still don't hear any significant high-end hiss. But since my 50+yr. ears don't function like they use to, I checked this on a frequency analysis app. I only see a slight/narrow bump around 19kHz. (unlikely to be what your hearing.) I selected only the room-tone since that's where one would notice hiss and BG noise the most. Are you sure you're not hearing natural acoustical borne ambiance?
Could your sound-card or other playback electronics/amplification be the cause?
FWIW, In my opinion, Bose speakers are normally not good reference monitors..Far from flat, with hyped highs and lows. The AKG-240m HPs should be pretty accurate though. I'll post the frequency analysis image later on.
Cheers, Rick
Addendum:
PT-test.wav, room tone around 00:00:06:25

Scott,

I have a similar audio setup for my rig. A Zoom H4n and a Rode NTG3. Your audio clip sounds very similar to the results that I have been getting. I usually run the Zoom between 80 and 95 percent on the gain and the preamps are a little noisier than I would prefer at that level but nothing has been too bad. I actually thought your clip was a tad cleaner that some of the stuff I've been getting lately. After reading this thread I think I'll turn off the Mix to Mono option. That would avoid summing two channels of noise together with one mic.

Robert. Awesome info with the Juiced Link thread. It won't help me for fixing my current problem but it's good to hear that I'm not going crazy, and that others have shared the problem. It makes perfect sense that an external preamp sounds better than the built in preamps on the Zoom.

Rick, perhaps the problem is with my listening gear. The hiss is definitely there, but you are right that it is more apparent with the Bose system. It is not nearly as bad on my AKG's. That said, most people that will end up watching my film back will either watch it on their computer speakers, of which many people do have speakers that kick up the highs and lows. I guess you could go crazy though trying to make sure your product sounds good on every available type of speaker.

Using a 3 band EQ on FCP, I boosted the low gain up to 8, and cut the high gain down to -6. It already sounds a lot better. It does not eliminate the hiss, but cutting back the highs does help, and it sounds more full now.

Does this sounds about normal for EQing dialogue? What do you guys typically do to dialogue before calling it done? I didn't used to mess with audio settings at all, but now I'm getting to where I wouldn't let a project go public without a little audio clean up, much like how I wouldn't call something finished until I've done at least a little color correction.

What kind of stuff do you guys do for basic audio treatment?

You need LOTS and LOTS of power to effectively drive the AKG K240M headphones, which is high impedance. (600 ohms) So your HP amp may very well be contributing more than just a little noise.
I'm not familiar with FCP's 3 band EQ, so I can't say what's excessive. (though boosting the lows 8 dB on a 3-band EQ sounds a bit abnormal)
'Typically', for processing I use, if needed: Noise Reduction, EQ, Compressor. On the Master bus I insert brick-wall limiter to catch any peaks from exceeding my target peak level. Sometimes I'll substitute or add a multi-band compressor on a track, sub-master or master.

Before I finalize a clients mix, I listen to the project on different sets of pro and consumer speakers, large and small, expensive and dirt-cheap, with and without sub-woofers. Minor compromises usually need to be made to sound good on all. I usually make my final track level adjustments on 30+ year old Auratones, where less than 1dB SPL level changes are audible on the all important mid-range.

if you don't have proper 'accurate' monitoring in an acoustically treated environment, any changes you make to the audio may not be accurate: like trying to color correct an image on a consumer TV that has hyped/inaccurate colors in a room with red lights.
if your film is being released and has a chance to get attention with 'known actors', you may want to think about getting a professional to mix the audio...
other than that, you can do it your self, but be sure to check the results on as many different systems as possible to see how it translates. and, though not always, it is generally better to cut frequencies than add them.

In FCP select your stereo track then hit Alt-L to separate them in to two mono tracks, then delete the one you don't need. You could also have hit the mute button for that one track.

Alternatively, select the stereo track then go to the Modify Menu then uncheck the Stereo Pair item.

I have the same equipment. It has been a while since I did all my tests, but here is how I remember it. Using the NTG2 pluged into the H4n with XLR mono mix down off, I needed level settings up in the 90-100 range to get around -12 db as you experienced. When mono mix down is on the level dropped to about -18. Splitting the signal to both channels and dividing the gain?

Here is the kicker though. When pluging the NTG2 (or any other mic for that matter) into the mini jack the record level only needs to be in the 60 range to get to -12. I am not sure if this is because they are unbalanced or because the mini plug uses the pre amps differently or what. I am sure that is partly responsible for the increased gain in Roberts test with the Juiced Link, as the output from the Juiced Linked is a mini plug.

I was very disappointed when I discovered this because I sold my Marantz 660 to get the H4n. With the 660 I never put the record level over about 5 (0-10) to get decent gain. The 660 had a lot of hiss, but that is well documented and why I sold it.

I have been getting good results from the H4n running through a mixer (XLR) so I can keep the record levels down in the 60 range. I have been meaning to call Zoom to see why the mini input is so much hotter. If I do I will post.

Hope this helps.

I just put my headphones on to test my new H4N+NTG-2 combo and was horrified to hear only the left channel. I haven't read the manual yet, just hoping there's a way to preview audio binaurally.

In the 4-channel mode, if you turn on 'Stereo matrix' on Input 1, you get to preview audio binaurally, or at least I think you do ( I am just starting out/have been using the H4n for two months).

A question Ihave right now is what's the difference between Mono Mix on an input in the H4n's stereo mode, and Stereo Matrix on an input in the H4n's 4-channel mode.

Loving the learning!