I will be video recording my sons' classical music performances tomorrow evening. Until recently, I used a stereo AT825 microphone directly attached to D5MII or attached to H4N via XLR and synched later in post. I got better results with the later but synching always takes time.

This time I am thinking of using H4N as preamp for D5MII. I performed a test recording a few days ago by attaching AT825 to H4N via XLR and also using a TRS-to-TRS cable to connect PHONE/LINE out of H4N to MIC input of D5MII. Initially, I was skeptical about this set up since the source audio coming from PHONE/LINE OUT of H4N is dependent on the VOLUME adjustment level. After tweaking the volume levels on H4N and REC levels on D5MII, I found that if I keep the PHONE/LINE OUT volume on H4N at 20/100 and REC level on D5MII at 40/100 I get very good audio in the video. In fact, by listening, I cannot tell any difference between the audio WAV file recorded in H4N and the AAC audio recorded in the MOV file. I believe this set up provides clean audio to D5MII.

I am now thinking of using TC-D5 PROII (portable professional cassette recorder from 1980s) as a preamp for D5MII. This recorder might have a better preamp and also has real RCA type LINE OUTs. The only disadvantage is portability, since it is larger and heavier. I haven't done a test yet.

My questions are:

1. Despite my subjectively good test results, I am still not sure if the setup I used to connect H4N to D5II is the correct way of doing it. Is it possible this setup may ruin the audio on my video or even my equipment?

2. Does the Sony TC-D5 PROII ( TC-D5 Pro 2 (http://www.walkmancentral.com/products/tc-d5pro2) ) recorder have a better preamp than Zoom H4N? Is it worth to try it with D5MII?

I appreciate your help and comments, thank you.

You run a real risk of overloading the camera's mic inputs using ANYTHING with a line output as a preamp and frankly I don't see the point. You're still sending your signal through the camera's noisy marginal mic preamps regardless and that cancels out any advantage to you might get with an external preamp. If you're going to the trouble of using the H4n in the first place, use its recording as your primary audio and treat the camera audio as a scratch track to aid in syncing and then to be discarded. The cassette recorder would be out of the question since the big drawback of analog tape is that it is almost impossible to maintain sync without elaborate measures. Compared to syncing the files from your Zoom, syncing a tape from the Sony will a major, perhaps insurmountable, headache.

There are many attenuating cables available to go between the H4n and a dSLR mic input, some cables also have a headphone jack split off to allow monitoring. That's what I would use in this case and record the same audio on both devices with less chance of over-driving the 5D MkII input and be able to monitor at the same time.
Sescom makes many cables for this, or you can make your own if you have the soldering skills and a schematic.

Thank you for the replies. I think this is the attenuator cable you recommend which I found at BH.

Sescom LN2MIC-ZMH4-MON Line Out to Camera Mic In LN2MIC-ZMH4-MON

Most people gave good reviews, a few had some noise problems, not sure if it was due to their set-up. I will probably order one but still thinking whether I really need it. I am able to attenuate the line-out signal simply by turning the volume adjustment down to 20/100.

Also, another question is what Steve raises. Since the final audio is captured by D5MII's 'marginal' preamp, does capturing audio with a quality preamp then sending to D5MII really help with the final quality of the audio? To my ear it sounds like it is as good as it is recorded in H4N. I agree synching audio in post gives the best results but it takes time.

In regard to cassette recorder, I was thinking to use it only as preamp, was not planning to use analog recording on a cassette.

This evening, I will use the system as I tested. I will let you know the results.

Thanks again.

Thank you for the replies. I think this is the attenuator cable you recommend which I found at BH.

Sescom LN2MIC-ZMH4-MON Line Out to Camera Mic In LN2MIC-ZMH4-MON (http://www.bhphotovideo.com/c/product/750963-REG/Sescom_LN2MIC_ZMH4_MON_3_5mm_Line_to_Mic.html)

Most people gave good reviews, a few had some noise problems, not sure if it was due to their set-up. I will probably order one but still thinking whether I really need it. I am able to attenuate the line-out signal simply by turning the volume adjustment down to 20/100.

Also, another question is what Steve raises. Since the final audio is captured by D5MII's 'marginal' preamp, does capturing audio with a quality preamp then sending to D5MII really help with the final quality of the audio? To my ear it sounds like it is as good as it is recorded in H4N. I agree synching audio in post gives the best results but it takes time.

In regard to cassette recorder, I was thinking to use it only as preamp, was not planning to use analog recording on a cassette.

This evening, I will use the system as I tested. I will let you know the results.

Thanks again.When you say recording in the camera sounds as good as recording in the H4n, how are you monitoring? Are you listening on computer 'multimedia' speakers or do you have access to good quality studio monitors? It may be that your playback environment doesn't reveal flaws that are actually there.

I am back from my sons's concert and I would say my recording adventure was a failure. There is occasional on-and-off interference noise in the audio of D5II files. This noise is similar to the ones described in the bad reviews of Sescom cable at BH website I posted above. I am fortunate to have the original WAV recordings of H4N which I can synch to video. Those don't have any noise at all. Now I believe in Steve, thank you for your advice. I will not use this method anymore, I will rather synch.

For your question regarding monitoring, yes I used Sony studio monitor headphones to listen to the files.

Can you post a short sample of the problem audio from the camera? How will you record audio on the camera for your next project as a guide for syncing? I'm glad you obtained good audio on the H4n this time, so I wouldn't call it a failure.

Here is the link for sample D5II audio with noise from last night. The WAV file from H4N has no noise at all. I did not have this problem during my tests at home.

http://dl.dropbox.com/u/86774786/MVI_0903.m4a

For my next project, I will use the intrinsic mic of D5II or another stereo microphone as guide for syncing.

To me those noises sound like a poor connection due to either oxide or fingerprint oil buildup on the connector/cable contact points, or stress on the cable due to its own weight or not being secured to the camera base so a short stress-free loop of cable is plugged into the jack.

I would gently clean both ends of the cable with a soft cloth and then don't touch the conductors with bare fingers. The only way to clean the jacks is to clean the cable, plug it in, gently rotate it, unplug it and then clean the cable again. Do this a couple of times taking care not to use any more force than needed.

I don't think this camera's mic jack has plug-in power. If it does have plug-in power, this must be disabled in a menu, or if it can't be disabled you must use a cable or interface with blocking capacitors to prevent the plug-in power from causing noises if your device doesn't need plug-in power.

I will clean the cable as you described. This is same TRS-to-TRS cable I used when I did testing at home which worked very well at that time. I don't know what the difference was when I did the actual recording.

I cannot find anywhere in the manual whether the MIC input jack of D5II has plug-in power or not. I suspect it might have some low voltage there, because, one day, the battery of my external condenser microphone totally ran out but I was still able to record somewhat low quality sound, I guess some kind of voltage (from D5IIs MIC jack?) was still driving the microphone. There is no mention of this in the manual. There is nothing in the menu to turn the power of the mic jack on or off as well. I will look into the capacitors you mentioned but I think I am more leaning towards recording with H4N and syncing during post from now on.

Thanks again.

I'm afraid there's not really good way to do this.

The issue is that unless they've made a change to the firmware that allows manual recording levels and defeat of the Automatic Gain Control built into the H4n - it won't make a whole lot of difference what you put in front of the mic input.

It's that AGC that "pumps" the volume up during quiet passages.

Outboard units like the Studio One mixers tried using a pilot tone at a frequency that couldn't be heard to fake the AGC into thinking that there was always a signal present to keep the gain control from pumping - but thats NOT the same as having a clean noise floor to start with since that's going to affect the dynamic range of your recording for the worse.

It's MUCH better to just record to the card in the H4n and don't mess around with trying to capture usable audio on the 5DMkii unless you're just using it as a scratch track to replace later.

FWIW.

Bill, the Canon 5D2 firmware has had manual gain control for some time now. Magic Lantern offers additional quality as you can control both the analog and digital gain independently. Canon has the analog at full blast and limits the user to controlling the digital gain only. Using ML, one gets roughly a 9dB S/N improvement.

AGC is still available. (I generally record with AGC ON when I want a sync track for an external recording.) But manual is available out of the box as well.

I think I have an explanation why I had noisy audio during concert recording and perfectly well audio during my tests at home. The only difference was the lens on D5II, which was a fixed 35 mm lens at home whereas 24-105 mm zoom lens with IS during live concert. I was using a monopod and the camera was slightly moving. I believe the IS motor caused the interference noise in audio. It did not interfere with H4n audio but only with D5II audio.

Anyone experienced anything like this? I have had the internal microphone picking up IS motor sound in the past, but nothing like this (electronic interference) before. In fact, I have used the same IS lens with the same microphone directly connected to D5II (no H4N in between) in the past without any interference problems.

Any comments? Do you think IS motor might be causing this interference in audio?

BTW, I sync'd the audio from H4N and created a DVD of the recital, the audio sounds very good. I learned a lot from this forum, thanks for your help.

It is possible the IS is creating the interference. Can you substitute a different (length, shielding) mini-TRS to mini-TRS cable between the H4n and 5D MkII and retest with everything else the same?

You have to be very careful with 3.5mm <> 3.5mm cables. Some are shielded, and some are not!

Local retailers, e.g. Radio Scrap, have at times sold unshielded cables that were apparently designed for headphones, where shielding is not necessary. Of course if you use one of these for a mic circuit, you're leaving yourself open to all sorts of noise pickup. Other times you might get a cable there that actually is shielded. It's a crap shoot.

Sadly, someone -- manufacturer, sales dept., package designer, retail outlet -- doesn't think shielding is an important factor, and so the packages are very rarely marked! If you get cables from a Lowest Common Demonimator retail outlet, you need to test the cable very thoroughly to be sure it's shielded, before using it for an actual gig.

Even with a shielded cable, if the circuit is unbalanced, you're only partly safe. The shield protects the internal signal wires from electrostatic noise, but the shield itself can still pick up electromagnetic noise, which is then coupled into the signal circuit.

Of course your best bet is to purchase a cable that is known to be shielded, from a dealer who is known to be reputable and who caters to people in the industry... not just to kids with iPoos.

I don't know it is shielded or not, but this was the cable I used. This came with a cheap AT wireless microphone system I purchased a few years ago. I think I'll go ahead and buy the Sescom cable which is shielded.

If that cable came with a wireless mic system, most likely it is properly shielded. The culprits are usually intended as rather long "headphone extension" cables, where shielding is optional

After re-reading a lot of this thread, and listening to your audio file, I agree with Jay Massengill. I think you are hearing noise from the varying circuit resistance caused by a dirty connection somewhere. Whenever any one of the connections (between mixer and camera) moves even slightly, dirty contacts can generate that kind of noise. Jay's cleaning instructions are good, and very important!

Also, the problem is greatly exacerbated if the camera supplies "plug in power" over the mic input jack. The voltage is typically between +5 and +9 volts. Even a tiny bit of changing resistance can produce a few millivolts of change in the DC voltage. Now a few millivolts (let's say 5/1000 volts) seems like a tiny amount. But that's very much comparable to the audio voltage coming out of a microphone. So the camera preamp boosts it nicely and it becomes very audible.

If possible, disable the "plug in power" if you're feeding the camera from a mixer's output.

If not possible, then either modify the mixer by adding a series capacitor ahead of the output jack, or else have someone build you an isolation box/cable with such a capacitor inline. The capacitor isolates the DC voltage to the camera end of the system, so changing resistance in the cable/connections will have much less of an effect. (The capacitor itself should cost less than a dollar; it's the connectors and labor that will run up the price.)

But even if you turn off "plug in power" or use a capacitor, it is still important to get all the connections perfectly clean!

Bill, the Canon 5D2 firmware has had manual gain control for some time now. Magic Lantern offers additional quality as you can control both the analog and digital gain independently. Canon has the analog at full blast and limits the user to controlling the digital gain only. Using ML, one gets roughly a 9dB S/N improvement.

AGC is still available. (I generally record with AGC ON when I want a sync track for an external recording.) But manual is available out of the box as well.

Fair enough. I haven't tried to use the camera audio on my 5d in the entire time I've owned it (nearly 2 years now) it since it was so awful originally.

I am interested, however in just how good the mic circuit in a DSLR could be. (my experience is that the standard video manufacturer adding an audio circuit to a video device is typically more adding a "feature" than designing for quality - but I could be wrong.

You indicate that even adopting the hassle of booting into Magic Lantern on every shoot to avoid the Canon EPROM settings, you can get an 9db improvement. But 9db improvement over what? Is there any reliable source you've seen that's done a properly weighted audio test of that system to reveal the S/N, noise floor and dynamic range measurements for a 5d?

I seem to remember that Ty Ford did a basic test and was NOT impressed. And that someone from the audio world (Perhaps Jay Rose?) did one as well as was even less impressed.

Before I'd ever use any camera for the single most critical information carrying signal I'm recording (my audio track!) I'd want to be sure I wasn't shooting myself in the foot with something that's baking in deficiencies in my recording.

I'd love to be able to change my thinking on this because on-camera audio is certainly more convenient than double system. But I'm leery largely because if somebody had found a way to make 5d on-camera sound even reliably close to the quality of double system, I kinda think that would have been BIG news in the industry.

Have you seen any reliable tests? And if so, where could I find them to review?

Years ago, I performed this test:
5. Canon 5D Mark II Audio Exposed - Noise on Vimeo

Since then, juicedLink has released new product with higher gain and Magic Lantern now allows you to turn off the low-cut filter.

Are the results as good as double system? No. It's a 16-bit recording, rather than 24-bits. And the results are crisp but slightly harsh. I think the A/D's anti-aliasing filter is poor - not unlike DSLR video.

My general rule is to shoot double system when I have a crew or when I need the best results. When shooting solo, I generally record into the camera. Why? Two reasons: 1) recording into the camera is simpler and less prone to mistakes, and 2) when shooting solo, I'm probably doing an interview in the wild where the sound quality into the DSLR is more than good enough for the application.

I use the following methods:
* For lightweight solo work in the wild, I go with the VideoMic Pro into the camera. The gain really helps. But it's camera mounted, for better and worse.

* For solo interviews, I use the juicedLink and lavaliers or a mic on a stand. The exception is at tradeshows. I use a wide lens and get close with the VideoMic Pro using a monopod. It keeps people from walking in front of the camera and by not asking to mount a lav, I give the subject one less reason to say "no".

* For a sync track, I use the internal mic with AGC enabled. It's simple, reliable, and good enough for syncing an external source.

The best solution always depends on the problem at hand. :)

So, essentially the bottom line is that if you record audio to camera directly on a DSLR, you've got to be in a circumstance where you feel the convenience trumps audio quality to at least some degree.

Obviously, there are circumstances where the trade off is sensible. And if you're willing to jump through moderate hoops - you can get closer to optimal results than the stock system plus software provides.

Which I think is a very fair conclusion.

It leaves the judgement as to what is "acceptable" quality practices up to the individual shooter.

Which is OK by me.

I think that's exactly right, Bill.

BTW, the tradeoff hasn't been signal to noise, for me. The noise floor is down near the limit of 16-bit recording. (Of course this depends on the sound pressure levels, mic sensitivity, etc. If the signal is faint and you boost the gain in post, noise increases.) In fact, the S/N with a juicedLink preamp and Magic Lantern beats the results for a Zoom H4n or Tascam DR-100 (the original version, anyway.) No, the tradeoff in quality has to do with the slight harshness from a DSLR recording.

Externally, we use the Fostex FR-2LE, which has low noise, friendly operation, and a smooth, pleasing sound. The downside with the Fostex is that it's large and unwieldy for a solo shooter. It also has a plastic construction and doesn't feel robust for harsh environments. I don't want it flopping around while hanging on a shoulder as I'm running around trying to frame the image. When I'm indoors and can set it on a table, I'll use it solo when sound quality really matters. Other than that, it's best used by a dedicated audio person on a crew.

Is the harshness from a DSLR bad? That's hard to say. Given a controlled test, an audio pro won't like it. Most people won't notice it. Use it well in a real-world shoot with a good mic and it's going to be fine. But when sound quality really matters, go external. And use a crew.