Quality of EX1' mic-preamp?

[Piotr Wozniacki]

I am after some more tests. Using either the internal mic, or the ECM-673 shotgun, the only distorsion with even a considerable wind is the low-freq rumble.

With the stereo Edirol CS-50 however, even if I attenuate below the default -41dB, apart from the rumble the higher frequncy clicks/squeals appear. Of course I'd blame the mic, were it not for the fact it worked great with the V1E...

So, I think Bob's theory about the phantom supply running out of power at the low rumble frequencies seems the only explanation. After all, both channels are drawing power - unlike with the ECM-673 which of course is only using one!

Please anyone with either a stereo mic like the Edirol, or with 2 mono shotguns, perform some tests; what is needed is some wind to induce the very low freq rumble and both channels being loaded with the phantom power.

If anyone confirms my findings, I hope this can be adjusted in a firmware upgrade. Anyway, I'll know what to draw the Sony Prime Support attention to.

On the other hand, when I decrease the output volume (AGC off, level at 4-5), the distorsion is gone (only some bass rumble).

[Steven Thomas]

I have yet to see this problem.
I will look harder for it.
I have Neumann and Oktavas to try.

If it did turn out to be the phantom power supply, no firmware upgrade will fix this type of issue.

Also, you can't just go by the levels set by the camera, it depends on the source signal.
I'm sure you know this.

If the distortion goes away at 4-5 level set at your loudest passages, that should be your "ideal" level.

Also, I'd like to know what the LCD level display indicates. If it's trim levels to the EX1 mic pres (which it appears), it would
of been nice to have some kind of reference markings . Since levels "just" hitting the far right of the display distort, it
can't be a digital reference with far right being 0dB.

I'd like to see reference makers on this trim meter display. This would give us refence to whether the mic pres are clipping.
Also, I'd like to have another menu option to also view (at the same time), a display at the A/D converter level to let us
know when we maxed the converter "0dB" 16 bit word and also have a digital "clip" display blink to let us know.

[Craig Seeman]

I have a Sony ECM 680S which is a stereo microphone. It is 5 pin XLR with a 5 pin XLR to two 3 pin XLR adaptor. I power it from EX1s phantom power. It does not have the wind noise issue Piotr is having with his Edirol stereo mic.

As I stated above, I did hear an issue when I did not have the mic sensitivity properly set. Changing the sensitivity fixed the issue. So I don't think there's any inherent issue with EX1 phantom power to stereo mics.

[Piotr Wozniacki]

Craig,
Thanks for that info. I'll search your mic specification to compare it with mine; in the meantime please tell me which attenuation level you find optimal with your Sony mic (default is -41dB), and - when you use it with this optimum attenuation setting - whether it's louder or quiter than the internal mic. TIA

Piotr

[Craig Seeman]

http://bssc.sel.sony.com/Broadcastan...M680S_spec.pdf

http://bssc.sel.sony.com/Broadcastan...m=0&p=10&sp=81

I do remember having to alter the sensitivity a significant amount from the default.

I'll check the number when I use it with the new replacement EX1 I should receive from Sony tomorrow.

[Piotr Wozniacki]

The specs are very similar to the Edirol's with two exceptions:

- directional pattern are different
- impedance (100 Ohms Sony vs 200 Ohms Edirol)

I wonder how the latter influnce the load on phatom power...

[Piotr Wozniacki]

Craig,

I'm happy for you that the new camera you've got has the handle zoom problem resolved. Could you please check the mic settings you promised? I wonder what attenuation is needed for a stereo shotgun like ours to work properly... I am afraid, however, that this is going to be way too low.

[Piotr Wozniacki]

I've been wondering if anyone knows an explanation of the distortion nature ...

Definitely, it's only occuring with certain combinations of a specific microphone and the EX1 audio section. It's impossible to blame either of the two separately, as the mic (Edirol CS-50 in this case, but also others - according to this thread: http://www.dvinfo.net/conf/showthread.php?t=117354) is capable of distortion-free output, as is the EX1 with other microphones. Also, it's a penomenon that the pro cameramen / sound engineers must be familiar with - it's NOT specific to the EX1. Today I heard a live broadcast on TV, where (before they corrected it) a guy was talking to the microphone with huge fur on it, and yet I could hear exactly the same kind of distortion: the powerful bass rumble of the wind, accompanied by those clicks...

[Dan Brockett]

Hi all:

I have been reading this thread with great interest since I am on the fence about whether or not to dump my HVX in favor of the EX-1. I did a shoot with the EX-1 last week and the bigger chips and better S/N ratio, etc. are big pluses to me but this thread has me concerned.

Historically, almost all Sony sub-$10,000.00 camcorders have had audio that ranges from mediocre (Z1) to unusable (VX-2000/2100 PD-150/170) and I have been waiting to hear some critical ears on doing some audio tests with the EX-1. The shoot I did last week was tabletop so audio never entered into the equation.

What are all of your impressions of the audio quality of the EX-1 including the specific issue in this thread and of the general audio quality. I must say that the HVX has pretty good quality audio for a camcorder.

Bad audio quality rules out the EX-1 for me so let me know what your thoughts are.

Best,

Dan

[Piotr Wozniacki]

Rest assured - the audio quality on the EX1 can be great (in fact, it's a DAT quality). The problem discussed in this thread is just one of the many EX1's... well... peculiarities? :)

[Dan Brockett]

Originally Posted by Piotr Wozniacki

Rest assured - the audio quality on the EX1 can be great (in fact, it's a DAT quality). The problem discussed in this thread is just one of the many EX1's... well... peculiarities? :)

Hi Piotr:

Hmm...I think I am talking myself out of the EX-1 for the time being. Too many of those peculiarities. I make a living with my camcorders and if they don't work correctly 100% of the time, it can cost me clients and reputation. Its 2008 and dealing with all of these initial factory defects sounds like too much of a pain to me.

The shoot I did, I liked the camera and the picture was impressive but that was in a studio on sticks. A lot of these other issues that you guys are running in to sound as if they could really screw me over on a shoot.

Let's take a look at the running tally

1. Vignetting debacle
2. Back Focus/ND debacle
3. Chromatic aberration issues
4. Paint flaking off of new camcorders

and now add this thread as a possible...

5. Sound issues with "phantom wind noise"...

Too many issues for me to consider at this time. Let's see what NAB brings and if Panasonic is ready to introduce something that will compete with the EX-1. I am sure that by the end of the year, Sony will have worked out most of these issues although you should be aware that when we went through the audio hiss/super low S/N ratio, bad tinny audio" debacle with the VX-2000,2100, PD-150, PD-150, the only thing that got Sony to even acknowledge that the problem existed was the threat of a class action lawsuit.

Hopefully if this is a real "known issue", Sony will acknowledge it and get a fix for it to all of you without having to resort to the threat of a class action suit.

Good luck,

Dan

[Bob Grant]

For what it's worth I've used the EX1 with a Rode NT3 mic. I found I had to reduce the input sensitivity by 20dB to avoid LF clipping from bumps or plosives. I suspect that's what's causing the problems here. The LF wind noise is overloading the preamps. There maybe some LF attenuation further along in the cameras audio ciruits however by then the damage has been done.
This ties is with what the waveforms looked like, typical analogue clipping, somewhat rounded tops. Possibly increasing input attenuation will cure the problem however if you're trying to keep as much gain as possible then the only answer would seem to be to stop the wind noise in the first place.

Dead cats are only part of the fix. The mic lead itself and the shock mounts need to be upto the task. Both of these will couple LF sounds into the mic. The best mic leads are the fabric covered ones that are very flexible.
For shock mounts not too certain what to recommend, the cats cradle kind of mounts seem to work well for my LDCs but are rather big. You'd also need to ensure that the rubber bands don't create whistles as the wind blows over them unless they're inside a zeppelin and then that's not going to fit on a camera.

[Graeme Fullick]

Bob,

You are certainly correct on this one. I don't believe that there is any problem with the EX1 audio - I have not been able to fault it, but I always use a mini-zeppelin and dead cat on all of my microphones - even indoors. I have used the Senn MKH416, Audio Technica 835ST, Senn ME64, Rode NTG1, Rode NT3 - all with no problems at all. Also use a Sound Devices 302 mixer with Sony ECM88 lav with no problems. The symptoms that Piotr describes are classic digital clipping of low frequencies - I think that he needs a 10dB pad on the mic as well as using the low cut filters. I don't know the Roland mic, but if it is hot (like the Senn's) you might need to be careful about how much gain you use. Piotr could try running the mic through a mixer and see if this fixes the problem - agree that this will not be great for run and gun work - but it will prove if there is a problem with camera.

Hope this helps.

[Akira Hakuta]

I am one of the people who has also had issues with their sound, with a Sennheiser ME66 on my EX1 producing the same distortion Piotr is getting. I noticed just now that when I adjust the gain level for channel 1 manually (which my shotgun is plugged into), I hear a slight clicking sound as the camera adjusts the level up or down to match what I am setting it at with the knob. Does anybody else get this sound? I tried recording a clip with this while I adjusted the level to see if it would get recorded and it in fact was recorded. I am now under the impression that something is wrong with my camera as that seems pretty unacceptable to me along with the other issues I'm having.

[Piotr Wozniacki]

I am not sure whether my audio problems (high frequency clicking, accompanying the usual bass rumble - e.g. from the wind) are the same as those described in the similar thread here:

http://www.dvinfo.net/conf/showthread.php?t=117354

- but anyway, I'd like to update you that they are NOT limited to certain microphones use, as I thought earlier (just to remind you: earlier in this thread, I posted a sample of the distortion I was getting from my sensitive Edirol CS-50 stereo shotgun, indicating that nothing like this ever happens with other mics, including the EX1's onboard stereo microphone).

Well, with a really strong wind I seem to be getting exactly the same distortion from other mics, as well! Which means this is definitely the internal, EX1's audio section related, problem.

In this context, I'd like to draw your attention to very valuable observations of the person under the nick of "Basspig", who has been performing in-depth testing of various cameras' audio capabilities, but - due to some reasons - was stopped posting here ;)

Just read his comments scattered elsewhere, like e.g. here:

http://www.dvxuser.com/V6/showthread.php?t=131244

The bottom line is: we need to limit the input sensitivity way below what sounds "loud and nice", or - once the mic gets heavily loaded (like with a stronger wind blow) - the limiter will let you know it actually IS there, in a very nasty way.

I tried and tested Basspig's suggestions, and indeed - most of the distortion can be avoided.