How to record bicycle rides with minimum wind noise?

[-sandro-]

Hello,
I'm new here!
I'm writing because I'm desperate trying to find a solution for my problem.
As a hobby I wanted to start a youtube channel where I would record videos of my hikings and walks, mainly in nature with no talking. Among that I wanted to add bicycles rides (nothing extreme) while capturing ambient sounds and the bike sounds. So a stereo wide audio is preferable.
For this purpose I tried to attach my recorder (tascam dr40, I know it's not that good) to my body since on the bike itself is a no go due to the bumps and rattling noise. The results are pretty usable. However for the wind noise I can't find a solution and I'm starting to think there isn't any in this case.
I attached the microphone on my back with a dead cat thinking it would block most of the wind, I was wrong.
I'm not getting any clipping but still the rumbling makes the overall product not watchable (it's supposed to be relaxing content ).
Do you have any suggestion? I think that even if I buy the most expensive dead cat out there it won't be able to stop this kind of wind coming from all sides. I was thinking some kind of a cage but I'm sure if they even exist or could make a difference.
We're talking about 20-25km/h average speeds with burst up to 45km/h even tough I think I should avoid these speeds all together since the turbulence becomes incontrollable.

Thank you so much in advance.
Sandro

[Hugh Robjohns]

I don't know what 'dead cat' you're using. Rycote make this one for the DR40, and I use something similar on my Olympus OM11:

https://mymic.rycote.com/products/tascam-dr-40-mini-windjammer/

However, these kinds of attachments are inherently limited in how much wind they can cope with, and poor fitting will compromise their abilities very significantly.

They have to be fitted tightly to ensure no air currents can get in around the mic capsules, and turbulent air flows over and around the recorder itself will cause mechanical noise that is passed directly to the mics as well. So shielding the recorder from as much direct air flow as you can is always helpful. I'm surprised you say placing it on your back didn't help.... but the devil is in the detail and you might need to experiment a bit to find a location that really is out of a turbulent air stream.

But fundamentally, these kinds of 'dead cats' don't create a large enough zone of still dead air around the mic capsules to provide a significant reduction in noise in strong wind conditions.

If you look at the windshields aimed at professional users you will see they work by creating a large zone of still, dead air around the mic by enclosing it in a large aerodynamic frame covered in a sound-transparent fabric, and then the 'dead cat' long-fibre fur is placed outside that. This kind of arrangement can cope with much higher wind speeds... although there will still be a practical limit.



Applying a high-pass filter will also help to reduce the audible intrusion of low frequency wind rumbles.

[Sam Spoons]

A while ago I had a broadly similar problem with drum overheads at a breezy outdoor (live) gig. Foolishly had not packed any pop filters but a suitably configured HPF almost entirely removed the problem. Drum overheads don't need much/any low end TBF but you could try that in post production on your recording.

[Hugh Robjohns]

...a suitably configured HPF almost entirely removed the problem. ...but you could try that in post production on your recording.

It can be very effective , as I mentioned above as well... but if the HPF comes after the mic preamp (which is almost always the case) you really do have to ensure that the mic preamp input stage itself isn't being overloaded by the often absolutely huge amounts of LF being generated by the wind -- especially if using omni mics (not a problem for the OP, but it can be when using lavalier mics etc).

You can set a level on the meter from the preamp output that looks to be below the converter's clipping level, but the input stage of the preamp itself can still be clipped by the VLF... Sometimes an input pad is required to prevent that -- which again is not an option for the OP's recorder.

[Sam Spoons]

Worth a try in post though, nothing to lose...

[-sandro-]

Hello everyone and thank you,
I'm using this windshield https://microphone-windscreen.com/winds ... dr-40?c=21
I'm not sure how it compares to the rode one but from the video sample of the product page I would say they're pretty similar.
I tried applying a HPF in post but it wasn't really effective.
I will post a WAVE sample of my last ride later so that you can try yourself if you want.

Do they make blimps used for shotgun mics for little recorders?

[Hugh Robjohns]

Do they make blimps used for shotgun mics for little recorders?

Not that I've ever seen... it would make it very hard to operate the recorder and observe the meters.

[-sandro-]

...a suitably configured HPF almost entirely removed the problem. ...but you could try that in post production on your recording.

It can be very effective , as I mentioned above as well... but if the HPF comes after the mic preamp (which is almost always the case) you really do have to ensure that the mic preamp input stage itself isn't being overloaded by the often absolutely huge amounts of LF being generated by the wind -- especially if using omni mics (not a problem for the OP, but it can be when using lavalier mics etc).

You can set a level on the meter from the preamp output that looks to be below the converter's clipping level, but the input stage of the preamp itself can still be clipped by the VLF... Sometimes an input pad is required to prevent that -- which again is not an option for the OP's recorder.

I'm trying to understand what you mean here (sorry I'm still a novice in the world).
I set a cut-off at 120Hz on the recorder. And still in post the removal didn't work because as you said there was a huge amount of LF generated by the wind.

[Hugh Robjohns]

I'm trying to understand what you mean here (sorry I'm still a novice in the world).

Wind noise can cause a microphone to generate a very strong output at extremely low frequencies. That signal level can, in some situations, overload the mic pre-amp's very first input stage (or the mic input transformer if present).

The gain control in a preamp normally affects the later stages of circuitry, so while it's possible to turn down the output level of the preamp, it's already been overloaded. So the meters can look fine, but the sound is already distorted...

This isn't something that happens often, but it certainly can happen in extreme wind conditions and I've suffered it myself on more than one occasion in my former professional life working on Outside Broadcasts and exposed locations shoots.

The solution is an in-line balanced mic attenuator placed between mic and preamp (you can also get in-line balanced mic-level high-pass filters to cure the same problem too).

Of course, these solutions aren't practical with your recorder...

But what I'm saying is that it's possible the LF problems you're getting could be caused by preamp overload beyond your control, and nothing you do in post-production will resolve that. Only a much more effective windshield would improve that situation.

And a much more effective windshield is a much bigger windshield with a good volume of still air between the surface of the windshield and the mic capsules.

[Luke W]

Now that we're a few good and sensible replies in, I just can't help thinking that this is the perfect chance to go for an exercise bike and a green screen.

"Cyclist Jumps Volcano" has got YouTube star written all over it.

[-sandro-]

Got it now!

Unfortunately this is just a hobby I want to try so I can't afford to spend a lot on money on this with high end equipment.
Is there a maybe a portable recorder that can do this? That is a HPF filter before the pre-amps? Or maybe external mics with function to attach to the recorder?

As for the windshield, what about two in top of each other?
I should try to use a rubber band that runs along the "joint" of the windshield maybe. In my tests I tried to run it "vertically" above the windshield and that definitely pressed the windshield on the mics and made things worse. Just the lower the noise though not solve it.

[Hugh Robjohns]

As for the windshield, what about two in top of each other?

I suspect that would give a rather muffled sound. As I say, it's really about creating that volume of still air around the mics, and moving the surface of the windshield -- which is where the noise is generated -- further away from the mics.

So building a larger DIY enclosure for the recorder is probably the way to go -- but make it as smooth and streamlined as you can to minimise turbulence, and cover it with an artificial fur fabric.

[ManFromGlass]

This is a long shot and maybe useless but if there were wind turbulence tests of a rider on a bike available to watch then you might find a less turbulent place on your body to place the recorder. Not a solution but might help a bit. Is there less wind just below the shoulder blades or just above the lower back?
Or what about a home made fur covered back pack? Like a wire cage covered in fur that you strap on?

[CS70]

Got it now!

Unfortunately this is just a hobby I want to try so I can't afford to spend a lot on money on this with high end equipment.

Just for clarity, a microphone which has a built in high-pass filter in the input stage is not necessarily "high end". You just need a small one. The behringer B5 for example, -10dB HPF on the mic (just the first I found). Your recorder should have an XLR input and even phantom power so all you need is a cable and a mount to the bike - perhaps a dampened one to attach to the bike, but you could also DYI some dampening using foam pieces, rubber and a clamp for example. You still put a foam cap or the cat on the mic, and see what happens.
Also, a GoPro without waterproof case might do just fine..

[-sandro-]

This is the test from yesterday. Don't mind the handling-like noise because the recorder was temporarily in my backpack pocket. As you can hear in the middle of the recording the wind noise became louder. I can think of two reasons:
- the windshield moved inside the back pack pocket so more air could come in
- the mic was more directed towards a more windy direction

https://gofile.io/d/Zjx71M

I'll look into the DIY cage...

Is there a cheap lavalier-like mic a HPF? Or another record that has that built in?

[Dan LB]

In my experience I have found it difficult to protect the built-in mics of these small ‘pocket’ recorders from wind. The Rycote windshield I have for my handheld recorder is mostly useless.

The solution I have found is definitely to use external mics. It’s much easier to shield an individual mic from wind.

My ‘pocket’ rig is an Olympus LS-P4 combined with a pair of LOM mikroUši mics shielded by Bubblebee windbubbles and sometimes Rode WS8 windshields if I need more wind protection but it’s imperative that the opening of the windshield is sealed from airflow so it does its job. It’s a very affordable and very effective setup.

[-sandro-]

The solution I have found is definitely to use external mics. It’s much easier to shield an individual mic from wind.

Hey Dan,
thank you for this input, I'll look into it. Since I was planning to buy the Roland CS 10EM anyway do you think I could do the same with these mics?

Also, do you know if it's possible to connect these 3.5mm stereo mics into the Tascam dr-40 that has two mono xlr-1/4 inputs? I would need to split the stereo signal, is there an adapter for this purpose?

[Dan LB]

I was planning to buy the Roland CS 10EM anyway do you think I could do the same with these mics?

Not as easily done with the Roland CS-10EM as they are also earphones, and they certainly won’t fit into something like the windbubbles. It will be difficult to apply wind protection to them when they’re stuck in your ears without a specialist solution like this:
https://www.thomann.de/ie/soundman_wind ... rofone.htm

I’ve not heard the Roland mics and I’d be curious to see if they’re any good.

Also, do you know if it's possible to connect these 3.5mm stereo mics into the Tascam dr-40 that has two mono xlr-1/4 inputs? I would need to split the stereo signal, is there an adapter for this purpose?

The Roland CS-10EM requires what’s called ‘plug in power’.
It is basically a DC voltage (usually 5V) that is sent from the recorder to the mics and is most commonly found on a dedicated 3.5mm microphone input.

The Tascam DR40 doesn’t have this feature. The only way to get signals in is via its XLR or 1/4” Jack inputs. The XLR inputs are able to supply phantom power but this is 48V and not suitable for the Roland mics. An adapter such as the Soundman PPA will sort out the interfacing but it’s not cheap at around €130. Røde also make the VXLR+ which does a similar job but only in mono so you'd need two. They’re only around €25 each however I’m not sure if splitting the stereo signal and using two Røde adapters will work. I’m also not aware of an off-the-shelf cable for splitting the stereo signal so you’d likely have to make that yourself.

Anyway, having said all of that, if using mics with a 3.5mm connection then a recorder with a dedicated 3.5mm microphone input (such as the Olympus that I have) will make things far easier and neater and there’s less things to go wrong. The use of adaptors is not the right way to do this. They are unreliable and they’ll break and/or get lost.

If you already have the Tascam DR40, then I would buy some mics with XLR outputs. The Line Audio OM1 or CM4 would be my first choice if budget is an issue.

[-sandro-]

In your tests what wind speeds were those separate mics able to withstand?

[Dan LB]

I wouldn’t be able to give you any numbers but with the WS8s I can record in a fairly strong breeze. If you need to record in stronger winds then look to Rycote or Cinela.