Switches to Ext. Mic on EX1r introduces audio noise?

[Bram Corstjens]

Hi,

I'm a brand new owner of an even so brand new EX1R. That's all great but I have just discovered that switching to the external inputs introduces quite some noise in the audio. With the internal mic enabled it's all crystal clear though, but as soon as I switch the inputs to external I hear this noise. This happens whether or not there's a mic connected to those ports.

The audio knobs are at the 5 position. I also had to set the attenuation to -65dbu (max) so it matches the sensitivity of my old FX1. Audio was in manual mode, wind filter off and limiter off.

So what's up with this? Why do the external inputs make the sound quite noisey and why then is the internal mic crystal clear? Live audio monitoring on the EX1R is even worse... Lots of noise and far worse than my old FX1... (which I still have at my disposal as a reference)

Anyone got a clue?

Thnx!

[Olof Ekbergh]

I have not noticed any such problem with external audio with my EX1R I got in the beginning of December.

There is no reason for this to be happening. Sometimes a bad wire will cause noise. There could be something wrong with your camera. Does it make a difference if you are on line/mic, and phantom power on/off, cable plugged into xlr's or not.

If you can take it back to your dealer, for a replacement. If it is mail order just get a RMA and send it back saying it is defective. All dealers should accept a return if it is delivered unusable.

[Bram Corstjens]

Hi Olof,

Here's a sample: www.multireel.nl/upload/ex1r_int_ext_mic.mp3

Ch1+Ch2 are on -65dBu trim (loudest), wind filter and limiter off. Volume knobs are at 50%. (This matches more or less the sensitivity of my old FX1 with the volume know at 50%)

I connected a sennheiser wireless G2 to Channel 2 and an old sennheiser mic (battery powered) to Channel 1. I set the Wireless mic's output so it matches the wired mic.

Then I play a CD on a portable radio and switch back and forth between the internal mic and the external 2 inputs. The internal mic sounds okay. Not particulary noise-free, but acceptable, but as soon as I switch to the external mic's the noise levels rise...

Noise levels do not drop when I unplug the 2 external mic's, but setting the input to 'line' level and upping the volume of the wireless sennheiser (I cant change the output on the other mic) does help!

How does your EX1R perform at -65dBu and at 50% volume? I would be a real bummer if there's something wrong with mine...

/edit
Ok, I did some more testing. Hooked up my FX1 with my 2 mic's (I use a home made dual XLR to stereo mini-jack cable with an sennheiser wireless and an old sennheiser shotgun mic) and recorded my voice. Then I hooked them up to the EX1 and did the same. Result: www.multireel.nl/upload/sony_ex1_vs_fx1.mp3 (first EX1 then FX1)
They appear to be quite the same after all, so I don't think there's something broken... However I expected a bit more since this EX cam is a lot newer and a lot more expensive!

One more thing though, as I mentioned before setting the input to 'line' and upping the output volume on the sennheiser wireless to max. gives very clean sound (albeit a bit low on volume) The sennheiser wireless seems to be perfectly able to output low noise sound. So I was thinking, what if switch back to mic level, lower the EX1 trim level to lets say 30dBu and change the volume on the sennheiser wireless to get to acceptable levels? Wouldnt that give me lower noise since the EX1 pre-amps are on lower volume and the sennheiser outputs clean sound?

Funny thing is the noise increases too when I up the volume on the sennheiser wireless!? Weird, right?

[Olof Ekbergh]

It may be that the wireless is kind of noisy, so turning up the volume on the Sennheiser and turning the input gain down on the EX1 should help that.

Can you test a known very good quiet mic like a me66. I use me66's and they are very good low noise in the EX1. I also have very good luck with Sony wireless mics.

I sometimes put a pad 12DB on the me66's in high noise environments, so as not to over drive the EX1 preamps.

I find the EX1R and EX3 to be pretty good audio units considering their low cost. There are much better solutions out there, but they are more money. I would say the EX cams are as good as anything in their price class. My opinion only, someone may prove me wrong.

[Bram Corstjens]

Just tested the old sennheiser shotgun mic against a sony ecm-957 mic. After switching back and forth between de old sennheiser and this Sony I discovered the old sennheiser adds quite some bit of noise by itself! So that one's back on the shelf for one thing!

The wireless mic and the Sony mic don't seem to add any noise luckely. Plugging them in doesnt add noise.

I did a recording with the sony ecm-957 of a CD I played in my CD-player: www.multireel.nl/upload/ex1r_sony_ecm957.mp3

This is as good as it gets, so I hope it can be confirmed nothing's wrong with my cam... If someone can confirm this, then I probably just expected a bit too much of of a step forward from the old FX1. But then again, maybe that one's pretty good already compared to other stuff around :)

[Bob Grant]

No camera has exactly stellar mic preamps.
Yes the wireless mics can be a tad noisy but you might need to get your head around gain staging and how that affects noise levels. If you want to work with low output mics and faint sounds consider investing in a good field mixer from Sound Devices. Not exactly cheap but they will outlast several generations of cameras and the mic preamps are as good as can be made.

[Marty Welk]

Originally Posted by Bram Corstjens

Hi Olof,

Here's a sample: www.multireel.nl/upload/ex1r_int_ext_mic.mp3

This particular sample i stuff into a audio program and the digital data signal is only going up to 10% of the total range of the digital range possibility. if you shot that low, then had to post correct it, you would be turning the noise up lots and lots.

no signal = high signal to noise "ratio" meaning if there was a LOT more signal there any existing noise would have been at a really low level. assuming this noise is via the cameras stuff and not something external.

www.multireel.nl/upload/sony_ex1_vs_fx1.mp3
this one the "wash" does sound very similar on both cameras, but when you start talking , the levels are much better, and after readjusting my volume, the wash sounds like a normal noise JUNK, that is really irritating when you get stuff like that. once you have a signal and the Audio is adjusted down the Wash noise is very low, but now i know it is there , so it will never go away :-)

the noise itself in THAT sample is .5% or less of the total range of the digital, or 1/200th if i did my math correct. (that all discludes any logrythm math which i aint doing) the signal was normal going to 50-70%

www.multireel.nl/upload/ex1r_sony_ecm957.mp3
this one the level of the noise (if that was the noise) is about .15% of the total range, and the signal went to over 100% and peaked over and was clipped in very minor places.

if we assume that the noise on the First clip was .5% and the signal only reaching peaks of 10% then . ? . ? . its no wonder why it sounded so noisey by the time i hear it at this end.
whatever you did in the 3rd clip, as far as noise goes , that was sweet :-) even if singal peaked over a very minor few times, it was bestest.

if i did the same test here, i would have to turn off the FANS, because they will make a wash sound similar to that, even the freeway 1mile away from here will put in some level of wash noise right into my mics. Then back again, If i want to record with all that STUFF on , and that stuff exisiting, then i will have to put a lot of sound into the mic itself (etc Etc) to begin with (override the noise with signal). Then i know there is some noise in the camera curcuits, so i will want to feed in a good signal to them too. then there is noise added every analog step of the ways (like my speaker amp), so i would want a signal that uses much of the digital range.