Nex 7 with External mic

[outdoorjake]

Hi,

I have recently tried to use a Rode videomic pro with my nex 7. The mic is working and sound is being recorded however there is a constant undertone hiss. I have tried recording in diferent places, so it is not a background noise. I have tried the mic out on my Mac and it works fine, which makes me think it is to do with the nex 7. I have fiddled with all of the settings on the mic, and it makes the noise regardless. Does anyone have any ideas of what this could be and how to fix it?

Thanks Jake.

[Mick2011]

Hi Jake, welcome to the Sony Forums

I'm not sure (I've not used a Rode before) but I'd say this was a audio gain issue, rather than a bitrate problem. As such there's no setting on the mic for it, it's something the camera deals with.

Unfortunately the NEX-7 (like all Sony alphas) only provides auto gain, so you basically have to deal with it in post-production. There are various tools you can use if you're interested.

I do know manual gain is something many alpha users have requested and there's always a chance it will be included in a firmware update.

As I say this is just a hunch, but it sounds like the most likely explanation.

Cheers

Mick

[cmosse]

Hi

as already mentioned here you can not set a manual audio REC level or disable the auto gain from the camera.

However there are some kind of adapters which will alloow to disable AGC and set the REC level manually. One of the most popular along "DSLR-filmakers" is the product from Beachtek:

http://www.beachtek.com/products/hdslr/

Another option is to use a high quality portable audio recorder. Sony offers some in their PRO lineup.

http://pro.sony.com/bbsc/ssr/cat-audio/cat-recorders/product-PCMM10%2FR/

Syncing the audio track to the video can be done in post processing; if you have advanced software like Premiere or Vegas Pro this can even be done automatically.

Michael

[Eric.D]

NEX-6 NEX-7 have Multi-shoe that takes ECM-XYST1M mic.

http://youtu.be/YUcUmi7ZcRY compares well to Rode, but not in quiet

http://youtu.be/-gDHiRqXkOY compares internal mic in wind

If the mic gain is quiter than the camera gain, then turning the mic to +20dB may encourage the camera to turn its gain down.

Oddly, I have also found a strange scratchy noise from a Rode VideoMic Pro that disappeared when I changed the battery - best to use a reputable brand. The noisy battery was giving full voltage, and worked fine in other mics.

However, recording quiet sounds is always a problem. Rode make a cheap studio mic, the NT1-A, which has very low noise, if used with a good pre-amp that will also power it. CAD Equitek e100s has even lower noise, but is discontinued.

The Beachteks give 20-30dB of gain, but Shure FP24 and Sound Devices Mixpre give 66dB, but without the ability to defeat the camera's gain.

Maybe best would be to use an external recorder (Zoom H4n, Marantz PMD661), and feed its headphone out into the camera's mic-in, just to help sync it later.

People mention 'Pluraleyes' for syncing in post.

If the problem is distance from your sound source, moving the mic from the camera to the sound will help - extension cables, Wireless mics ECM-HW2, ECM-AW3.