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ME66 windscreen, K6 roll-off filter (1 Viewer)

dixonlau

Well-known member
Malaysia
Hi,

I have some questions in regards of using ME66+K6 for bird sound recording. It is connected directly to Sony A7R3 3.5mm audio jack in, mounted on Rode SM3-R Shockmount (arriving soon) on camera body hotshoe mount.


Question 1: Windscreen suggestion

I have just got my Sennheiser ME66+K6 but no windscreen included. Currently, looking at Movo WS220 on ebay. I'm not sure if this is a good option or there are better one for bird sound recording of course ;)


Question 2: K6 roll-off filter switch

After reading the manual, I still not quite sure how much this roll-off filter will impact on the recording sound. If you have experience with K6, which would you suggest? I assume the switch label "Straight line" means OFF roll-off filter, right?


Question 3: Surrounding sound

I have done a brief recording test at home, the mic seems pickup a lot of sound from surrounding, neighbour's dog barking, human voice etc. Is it because I did not have windscreen put on? I tested with in-camera recording level to low and still picking up much surrounding sound. Or can I further process it in software?

I also have tested on my old Tascam DR-05. The result seems much better but, still picking up surrounding sound easily.

Any help or suggestions are very much appreciated. Thanks.
 

Borjam

Registered User
Supporter
Hi,

I have some questions in regards of using ME66+K6 for bird sound recording. It is connected directly to Sony A7R3 3.5mm audio jack in, mounted on Rode SM3-R Shockmount (arriving soon) on camera body hotshoe mount.


Question 1: Windscreen suggestion

I have just got my Sennheiser ME66+K6 but no windscreen included. Currently, looking at Movo WS220 on ebay. I'm not sure if this is a good option or there are better one for bird sound recording of course ;)
I haven't tried that one, but furry covers help a lot with wind. The most effective windscreens are the "zeppelins" but they are bulky and expensive. Maybe the most affordable solution is the Rode Blimp v2. For around $200 it has Rycote lyres for suspension and a furry "dead cat" cover.

Question 2: K6 roll-off filter switch

After reading the manual, I still not quite sure how much this roll-off filter will impact on the recording sound. If you have experience with K6, which would you suggest? I assume the switch label "Straight line" means OFF roll-off filter, right?
Bird song usually has very little low frequency content. The roll off filter helps to prevent preamplifier saturaton dude to loud low frequency wind noise. Remember that when wind induced low frequency noise is too loud you can't fix it after recording. That's why a low frequency roll off is present in so many microphones.


Question 3: Surrounding sound

I have done a brief recording test at home, the mic seems pickup a lot of sound from surrounding, neighbour's dog barking, human voice etc. Is it because I did not have windscreen put on? I tested with in-camera recording level to low and still picking up much surrounding sound. Or can I further process it in software?
A directional microphone will never be as directional as, say, a flashlight. A directional microphone will always attenuate off axis sounds improving the signal to noise ratio for the main direction So they will improve your recording.

But a directional microphone, especially a shotgun, won't do miracles. Parabolic reflectors are much more directional.

That said, indoor testing can be deceiving because sound bounces all over the place indoors. If you want to have an idea of the effect of a directional microphone test it outdoors with your headphones connected to the recorder. Especially if you have a somewhat nearby road you will notice how pointing the microphone properly reduces the road noise. But it will not make it disappear.

in short: A shotgun microphone helps a lot (and the ME66 has other very good properties such as a high sensitivity and low noise floor) but don't expect offending sounds to disappear. And a different recording won't help that.

You can further reduce some background sounds in post production, such as traffic noise, by simple equalization or even using some "clever" (I wouldn't say intelligent) filters that you can train with the background noise you want to reduce.
 

marcsantacurz

Well-known member
I use the Auray WSS-2018 windscreen. It seem to work well on eliminating wind noise.

As Borjam mentioned, trying to take out low frequency later is hard, so if you don't need the low frequency (there are some birds with low calls), it's best to trim it before it hits the recorder. It also means that the recorder, if using auto gain (AGC), will consider the low frequency noise less with picking an amplification amount.

The only thing I'd add to Borjam is if you're using AGC on the camera and the dog barking is the main sound, it will amplify that. If you have, say, a subject across the room talking to the mic and an off-axis dog barking, you should be able to notice the difference.

When I use my ME66/K6 on my Nikon, I often use manual gain, not AGC, so I can set it to the right sensitivity for the subject and not have the camera change the gain when the bird is quiet.

Marc
 

dixonlau

Well-known member
Malaysia
I use the Auray WSS-2018 windscreen. It seem to work well on eliminating wind noise.

As Borjam mentioned, trying to take out low frequency later is hard, so if you don't need the low frequency (there are some birds with low calls), it's best to trim it before it hits the recorder. It also means that the recorder, if using auto gain (AGC), will consider the low frequency noise less with picking an amplification amount.

The only thing I'd add to Borjam is if you're using AGC on the camera and the dog barking is the main sound, it will amplify that. If you have, say, a subject across the room talking to the mic and an off-axis dog barking, you should be able to notice the difference.

When I use my ME66/K6 on my Nikon, I often use manual gain, not AGC, so I can set it to the right sensitivity for the subject and not have the camera change the gain when the bird is quiet.

Marc

Thank you for your feedback. Looks like I will need further post-process the audio if I want more clean sound. Will test it out in actual field later days.

By the way, do you connect your ME66/K6 into some devices before connect to your camera? or you direct connect to your camera? I'm still very near in this kind of audio recording.
 

marcsantacurz

Well-known member
I go straight to the Nikon using the Sennheiser XLR-3.5mm adapter. I use a rechargable battery in the K6.

If I had a real recorder, I'd probably skip the battery in the K6 and use phantom power.
 

NorthernHarrier

Active member
K6 Roll-off Filter, Windscreen

I bought a Movo Photo WS220 windscreen, as an inexpensive alternative to a Rhode or something else more costly. I have not had an opportunity to test it yet on my ME66/K6, but I think it will be an improvement over the foam-only windscreen I was using previously.

As for the bass roll-off filter, I believe you are correct about the closed, versus the open position of the switch. Some people have cautioned others about using the filter, but for birds, I think it is reasonable to use it in most cases. There aren't many birds that have vocalizations with frequencies above the cut-off point of this particular filter. When you are going after one of those birds with lower-frequency vocalizations, you can always switch the filter off.
 

horukuru

Here I Come !
I turn it on too on the same setup with my Tascam DR-44WL and using T-link cable to record on channel 3 and 4. The Movo looks nice!
 

Jon.Bryant

Active member
On the issue of surrounding sound, as Borjam says a shotgun mic cannot perform miracles.

When I bought my first shotgun mic I too was disappointing by the fact that it picked up off axis sound. In reality sound reflects off surfaces and diffracts (bend) around objects - diffraction in particular is more pronounces for lower frequency noise - these effects mean that even off axis sound may be reaching the mic via a different path.

Shotgun mics use a mic housed in an interference tube, which effectively creates interference waves to cancel out off axis sound - prior to looking into this, I always through that somehow the mic actually amplified the sound in front, rather than filtering out sound off axis, but amplification of front sound only occurs with mics housed in parabolas.

Typically this filtering mechanism is effective for high pitched sound, but not very effective for low pitched sound, which I think is probably due to the way the low pitch sound diffracts - anyway it seems a consistent shortfall for all shotgun mics. It is a bit fiddly, but this can be worked out by looking at the frequency response charts for the mic, which should show attenuation for various frequencies from different directions - in these diagrams 3dB of attenuation is approximately a halving of loudness. The diagrams are however, for the mic testes in a studio, so without the effects of reflected sound, so are very much a best case.

As a barking dog covers a range of frequencies but- particular if it is a large dog - includes low frequency sound, some parts of the sound will be attenuated more than others, with the lower pitched sounds attenuated the least.

This is not perfect for recording birds, where I would generally prefer the lower pitched sound attenuated more, but I think this is beyond the capabilities of the technology and the laws of physics. Even with a directional mic, I therefore think that it is best to works when things are as quiet as practical (i.e. early mornings) and get the mic as close to target as reasonable practical, so that the ratio of any unwanted sound is reduced.
 

Borjam

Registered User
Supporter
Shotgun mics use a mic housed in an interference tube, which effectively creates interference waves to cancel out off axis sound - prior to looking into this, I always through that somehow the mic actually amplified the sound in front, rather than filtering out sound off axis, but amplification of front sound only occurs with mics housed in parabolas.

Typically this filtering mechanism is effective for high pitched sound, but not very effective for low pitched sound, which I think is probably due to the way the low pitch sound diffracts - anyway it seems a consistent shortfall for all shotgun mics.

It is also related to wavelength and the length of the interference tube itself.

In order to understand how an interference tube picture a sound source perpendicular to the microphone axis. Sound enters the interference tube through the side slits and each slit offers a different travel length. That means the phase for sound entering each slit is different.

Now, in order to have phase cancellation you need a minimum length for the interference tube. Otherwise, low frequencies will arrive slightly off phase from each other maybe offering some attenuation but not enough to offer cancellation.

Anyway, birds in particular are very high pass filtering friendly.
 

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