August 21, 2014, 06:52:16 AM

Author Topic: Audio Issue with New Mics / External Recorders  (Read 1224 times)

expatinasia

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Audio Issue with New Mics / External Recorders
« on: February 23, 2014, 10:37:36 PM »
Must admit that I was not sure if this was the right section of CR, but as it is about videography I thought I would post my question here.

In addition to my stills work, I use my 1D X for video - interviews and other things - and I recently purchased a couple of AT831b microphones. These mics have XLR outputs but of course the 1D X does not, so I purchased XLR to mini-jack and use a splitter that goes into the 1D X.

I am still testing these mics as they are different from the other ones I have used in the past, but when I use them together one mic is louder (and sounds better) then the other. When I use them separately they both sound the same.

The previous mics I have (and still like) are the very affordable ATR3350. When I use these two together with the splitter both mic volumes are exactly the same and of the same quality.

I know I probably should invest in something like a Zoom H4N which has XLR inputs, but I really would like to keep the amount of stuff I travel with, which is already substantial, to the absolute minimum.
So my questions are as follows:

1) Do you know what could be causing the difference in sound with my new mics (have already tried changing batteries in them both)?

2) Is the Zoom H4N the best option for an external recorder with something like the 1D X?

3) How much loss of audio quality is there in trying to use my new XLR mics with the 1D X in percentage terms?

4) Is there anything I could try that I have not thought of?

Thank you.
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Audio Issue with New Mics / External Recorders
« on: February 23, 2014, 10:37:36 PM »

sjschall

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Re: Audio Issue with New Mics / External Recorders
« Reply #1 on: February 24, 2014, 12:36:12 PM »
Generally speaking, you're going to need to go off-camera to get the best quality audio. I don't know what percentage of loss you're getting by splitting and adapting the mics straight into the camera. But what a Zoom (or similar) provides is a huge amount of control and power over your audio sources.

My best guess is that the splitter is where the difference in audio-levels is coming from. I haven't seen anybody do it that way before, so that's what raises the red flag.

spacetimeroger

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Re: Audio Issue with New Mics / External Recorders
« Reply #2 on: February 24, 2014, 01:37:30 PM »
The splitter is almost certainly the problem. When you've got sources going into a single input that you are summing together (if it is, indeed, summing) with a passive splitter, you are in for lots of problems. Does the splitter terminate in a stereo minijack or a mono minijack? Are the inputs on the cable for the mics mono or stereo? If it has any chance of working at all, the inputs for the mics need to each be mono, and the plug that goes into the camera needs to be stereo.

You don't necessarily need to go with something like a Zoom H4n (although an external recorder would be superior to the camera's audio recorder), but you may need to run a little line mixer or a preamplifier into the camera if you want it to work. The camera is likely getting confused trying to apply gain to the load of two microphones being passively split into a single input (if that's what's happening).

That said, a passive cable *might* work if it terminates into a stereo plug and isn't summing the two mono signals together. When two mono signals are summed the way you are doing it, you get all sorts of phase issues, the camera may see the load of the microphones incorrectly, there's just all kinds of things that can go wrong.

If you don't want to go for an audio recorder, you could get something like a Juicedlink adapter that will handle these signals correctly, and it will mount to your tripod mount.
« Last Edit: February 24, 2014, 01:43:49 PM by spacetimeroger »
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expatinasia

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Re: Audio Issue with New Mics / External Recorders
« Reply #3 on: February 24, 2014, 08:07:52 PM »
Thanks sjschall and spacetimeroger.

The splitter is almost certainly the problem. When you've got sources going into a single input that you are summing together (if it is, indeed, summing) with a passive splitter, you are in for lots of problems. Does the splitter terminate in a stereo minijack or a mono minijack? Are the inputs on the cable for the mics mono or stereo? If it has any chance of working at all, the inputs for the mics need to each be mono, and the plug that goes into the camera needs to be stereo.

You don't necessarily need to go with something like a Zoom H4n (although an external recorder would be superior to the camera's audio recorder), but you may need to run a little line mixer or a preamplifier into the camera if you want it to work. The camera is likely getting confused trying to apply gain to the load of two microphones being passively split into a single input (if that's what's happening).

That said, a passive cable *might* work if it terminates into a stereo plug and isn't summing the two mono signals together. When two mono signals are summed the way you are doing it, you get all sorts of phase issues, the camera may see the load of the microphones incorrectly, there's just all kinds of things that can go wrong.

If you don't want to go for an audio recorder, you could get something like a Juicedlink adapter that will handle these signals correctly, and it will mount to your tripod mount.

Wow, what a great reply. And I think you may be right. The inferior quality ATR3350 mics are mono, and they work perfectly in the 1D X using the splitter. It is only the two AT831b which are stereo which I am having problems with.

I will try and find a splitter that has a stereo plug on it and see if that works. Will also look into the Juicedlink adapter to see what that is and if that will work if the stereo plug splitter does not.

Thank you.
1D X + backup + different L lenses etc.

expatinasia

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Re: Audio Issue with New Mics / External Recorders
« Reply #4 on: February 25, 2014, 04:36:59 AM »
OK, thanks. Had a good look around today and while I am still hoping to find a splitter with a stereo plug, I am impressed with the Tascam DR-60D. While it is something else to carry it also gives me backups etc which is very useful.
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sjschall

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Re: Audio Issue with New Mics / External Recorders
« Reply #5 on: February 25, 2014, 11:45:12 AM »
Tascam makes great stuff. Zoom has two newer models out: the H6n and the H5n. Maybe also worth a look.

spacetimeroger

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Re: Audio Issue with New Mics / External Recorders
« Reply #6 on: February 25, 2014, 01:56:36 PM »
OK, thanks. Had a good look around today and while I am still hoping to find a splitter with a stereo plug, I am impressed with the Tascam DR-60D. While it is something else to carry it also gives me backups etc which is very useful.

I think you'll be much happier going this route. That looks like a nice recorder and it can connect to the bottom of your DSLR. The Tascam stuff also sounds a lot better (to me) than the Zoom stuff as far as recorders go. I've found Zoom preamps to always sound harsh and thin, Tascam is very good mid-level equipment and they have a solid reputation for making recorders that goes back quite a while. That recorder will also open up the possibilities for using all kinds of different microphones.

If you are shooting interviews, I do advise you to get a slate for syncing audio with the visual of the slate sticks closing. You'll find that if you sync to the sound spike the camera records and the sound spike the audio recorder records, that the camera will be off by a couple of frames. It's not an external audio recorder problem, the audio recording of the camera itself is at fault (this is the case with all DSLRs, and indeed most video cameras) -- the on-camera sound is actually out of sync with the camera picture by about 2 (sometimes 3) frames. It's not always terribly noticeable, but it's worth knowing. Anyways, you can test this with a slate and see for yourself :)


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Re: Audio Issue with New Mics / External Recorders
« Reply #6 on: February 25, 2014, 01:56:36 PM »

expatinasia

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Re: Audio Issue with New Mics / External Recorders
« Reply #7 on: February 25, 2014, 06:13:45 PM »
OK, thanks. Had a good look around today and while I am still hoping to find a splitter with a stereo plug, I am impressed with the Tascam DR-60D. While it is something else to carry it also gives me backups etc which is very useful.

I think you'll be much happier going this route. That looks like a nice recorder and it can connect to the bottom of your DSLR. The Tascam stuff also sounds a lot better (to me) than the Zoom stuff as far as recorders go. I've found Zoom preamps to always sound harsh and thin, Tascam is very good mid-level equipment and they have a solid reputation for making recorders that goes back quite a while. That recorder will also open up the possibilities for using all kinds of different microphones.

If you are shooting interviews, I do advise you to get a slate for syncing audio with the visual of the slate sticks closing. You'll find that if you sync to the sound spike the camera records and the sound spike the audio recorder records, that the camera will be off by a couple of frames. It's not an external audio recorder problem, the audio recording of the camera itself is at fault (this is the case with all DSLRs, and indeed most video cameras) -- the on-camera sound is actually out of sync with the camera picture by about 2 (sometimes 3) frames. It's not always terribly noticeable, but it's worth knowing. Anyways, you can test this with a slate and see for yourself :)

Thanks, and yes I have noticed the sync issues at other times. I always wondered what caused that. But a good idea with the slate. :-)

The Tascam DR-60D does seem to address a couple of issues for me. An important one is that it will keep weight off the 1D X mic jack port - two xlr cables in a splitter hanging from there was always going to be a concern. Plus the other is backups. If you set the Tascam to 4-channel (learning from the YT tutorials already) you get a reduced volume image of your recording on the unit itself plus you can plug the thing into the camera mic jack and the camera will record too. So I should not have any excuses for bad audio in future.
1D X + backup + different L lenses etc.

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Re: Audio Issue with New Mics / External Recorders
« Reply #7 on: February 25, 2014, 06:13:45 PM »