Shock mount, blimp and windscreen

Hi Petrus,

That is a great answer. :)

Regards
Leigh

Petrus said:
MattinSTL was faster, we had a night here...

Yes, Pettersen, your mic is not a shotgun, only hypercardioid at best. Putting mic inside a solid tube brings on all kinds or reflections, standing waves etc which never make the sound better. The pickup pattern will change in strange ways, too. Also wrapping the contraption in too much of non- acoustic foam wrecks havoc with higher frequences.

What comes to the suspension it might work, even though pro systems take into consideration also the weight of the mic to find the right resonance frequency of the system to fight exectly those freqnces where handling noices are the worst. Thus just criscrossing a bunch of rubber bands is not necessarily the optimum solution. This part is not nearly as critical as the tube thing, though, as it is difficult to make the sound worse with rubber bands, but with the solid tube that is quaranteed.

I am certain that the contraption you have made blocks wind, but at what cost???? (sound quality).
 
Hi MattinSTL,

I have a question for you.

I have seen lots of professional microphone has the wire matrix similar to wire mesh pencil cup you posted.

May I ask why these metal wire won't reflect the sound to effect the sound quality. I thought that metal wire is hard material and sound hit the wire will reflect.

TIA

Regards
Leigh
 
For every mesh (no matter the composition) there is a percentage of free space... not to mention the fact that the actual WIRE of the mesh is round anyway. A wire mesh cup, or tube like this is probably 75% open. A cardboard tube is 0% open. Let's say (just so I can get a usable number) that the cardboard tube is 1% open... in that case the wire mesh tube is still 7,500% more open then the cardboard tube and therefor 7,500% more acoustically transparent.

Plastic also reflects sound... but I never had a problem with transparency using any of the blimps I've owned.

Your mic is metal also by the way... and the percentage of open space which allows sound in is WAY lower (probably 15%) then a wire or plastic mesh tube... just be sure to have AT LEAST 2" of dead airspace surrounding the mic on ALL sides and it will sound good.

Beyond that I don't want to get into a hair-splitting analysis of the internal/external reflections of a wire mesh.

In the realm of reality there are certain (seemingly obvious) compromises which must be accepted in order to do or create anything. The presence of wires in order to create a structure by which to support a proper wind protection surface is something we can debate... but SOMETHING has to be there. Your thinking... in using chopsticks to hold a cloth over your mic... is not THAT far from DPA's concept... and it's a good direction to go in... but in a circumstance of actually challenging wind you will find that you need to strike a compromise of structural integrity and acoustic transparency... and I'd have to add (in my humble opinion)... a reasonably professional appearance.
 
Wow, I've really learned a lot now! Thanks a lot :dankk2:

I was wondering, if I drilled holes in the cardboard cylinder, or filled the inside with foam, would that work?

Also, did any of you listen to the sound test? I don't think it sounds too bad, but I'd really like to know what you think.

Can you give me some hint how to download your files?

First you must scroll down the page and hit the "free" buttom. Then wait for a couple of seconds and type the security letters. Last thing you do is to hit the "download from Net-Mirror 'Alpha" button.
 
Pettersen said:
First you must scroll down the page and hit the "free" buttom. Then wait for a couple of seconds and type the security letters. Last thing you do is to hit the "download from Net-Mirror 'Alpha" button.

I got following error

Download-session expired. Direct-links last a few minutes for free users and a few days for premium-users.
You requested this download-session from a different IP than yours. If you use AOL, try a different browser.


I have tried IE and mozilla browser both. I am using ADSL which shares IP.

Regards
Leigh
 
Drilling holeswill help, but you would have to drill an awful lot of them to make it worth while in my opinion.

I used wire mesh like chicken wire for mine, which works well and was dirt cheep ;-)

And before people get there panties in a wad about criticism, relax a bit and realize where it is coming from. Nobody insulted anybody. They just remarked that if someone thinks that a shotgun mic doesn't pick up sound from the sides, they don't know a lot about audio. That is a true statement. It's also something that has been discussed at length on this site. You can learn a lot here by doing searches and looking through the forums. Which is something you might want to do before building something. There isn't much that hasn't been tried here (especially by guys like MattinSTL who seems to spend a lot of time trying to develop good quality DIY stuff for those of us without money to burn...and does a great job) If that little comment was that big of a deal for you, what are you going to do when someone criticizes your movies?
 
No, I don't know a lot about audio, but I like to build things. That's probably my main concern, I just build things without doing any research first :)

When telling someone your opinion, it's really important to back up your opinions and telling what could be better. For we are all here to learn, aren't we?

By the way, I've learned something now; never build something without doing your research first :)

Still, I don't understand why a cardiod condenser like the AKG1000 should pick up sound from the sides when it's totally closed except for the hole in the front which is, obviously, not covered by cardboard. Someone explain?
 
Does this help?

akg1000.jpg


Just so you know I'm not trying to be a smart-ass... do you understand this graph? The surface of the mic diaphragm is the center of it... and the drawn lines each represent the mic's sensitivity in that direction to that frequency. So if you look up at the center of the graph and then look 90 degrees directly to the right... you see that the frequencies between 2k-4k are only 5db down from where they would be directly out the front of the mic. So if you place a tube over the sides of the mic you will block any incident reflected sound which helps define the acoustic space... and at the same time you will capture other frequencies which will most likely play havoc on that mic's smooth frequency response. It's likely that whatever resonance frequencies there are for that tube will be amplified and that will change the frequency response and tonal character of the mic in those frequency ranges... or simply put, the mic will sound like it's in a tube.

I wanted to post this to show you that even very directional mics still hear sound to the sides... it's just at a reduced level... and blocking this sound all together may improve the sound in some cases and make it worse in others.

I agree with the earlier post that said "do what works"... so if you have had luck with your setup then please don't change it on my behalf... I just want to inject the facts into this thread for anybody else that is contemplating building their own DIY mount and screen... this way they can approach it with the same design considerations that are engineered into a professional setup.
 
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Nearly all microphone elements are inherently omnidirectional. (We're not going to talk about ribbon transducers or boundary effect microphones here)

Just so we're all on the same page here; the types of microphones we use in this application convert acoustical energy into electrical impulses by sensing the compression and rarefaction of the air.

The way they are made to selectively accept/reject sound from different directions is actually very low tech, and very clever. The body of the microphone is designed with venting to let sound pressure interface with the transducer from the rear of the microphone as well as the front. Since sound entering these vents is 180° out of phase with the pressure hitting the front of the transducer, it damps the motion of the element, effectively cancelling itself out. Since the vents are aimed in varying degrees to the rear of the microphone, sound directly in front of the mic will be affected very little, and sound to the sides and rear will be attenuated.

A cardioid pattern microphone is named for its heart shaped response pattern: it rejects almost all sound behind the mic and gradually increases sensitivity as you move to the front. A hypercardiod pattern aims its vents more to the side of the microphone, so it is very rejective of sound coming from the sides but has a tiny "spotlight" of sensitivity directly to the rear that can be nearly as sensitive as the business end of the mic. This is an acceptable trade off in many applications as there often isn't any undesireble sound coming from that direction.

So, what makes a shotgun mic different? The size of the vents. In a standard microphone as I've described above, they exhibit what is referred to as "proximity effect": the closer the microphone gets to the source, the more low frequencies you hear. As you back the mic off the sound gets thinner, and as you get closer, the sound gets boomier. Also, as you look at a frequency response graph like the one above, you can see that they are more directional at high frequencies and at lower frequencies they go back to being more or less omnidirectional. This is because the lowest frequency that can be rejected is a function of the size and area of the venting, determining how long of a wavelength can interact with the back of the element. A shotgun mic has a long body with a series of openings so that it can maintain tight directionality across a very broad frequency spectrum. That's why it's important to make all sides of a blimp as acoustically transparent as possible.

Cheers,
Joe
 
That's what I was trying to say with my home schooled education... unfortunately I never graduated from the living room.
 
c1000 is not a shotgun mic...... it's a small diaphragm cardioid studio condenser mic. i have a pair of them. they do pick up from the sides much more than a true shotgun would. another thing to consider is that when you block the sides of a cardioid pattern mic like this, you lose all bottom end and spike the mids. this can be fixed somewhat in post with eq but as they say, garbage in, garbage out. i would get a real shotgun since you are going to all this trouble pimping your sound rig. other than that, good job. looks cool.
 
Wow, you guys are really great! I have learned very much in this single thread, and I really apreciate you're taking the time to explain everything as detailed and good as you've done :) I'm working on a solution to the cardboard problem, and I will post whatever I'll come up with.

Thanks again:dankk2:
 
So if you use the sound transparent foam you don't need the fur? If you get the fur you don't need the foam? Or you need both?

I found a peanut bird feeder at Lowes, 4 bucks, 3.5" diameter, 11" tall. Looks like it will work wonderfully.
 
All for $169!

All for $169!

I took a risk and bought this setup:

http://cgi.ebay.com/Blimp-Windkorb-Windshield-Mic-Suspension-Fur-coverFree_W0QQitemZ110012951348QQihZ001QQcategoryZ3319QQtcZphotoQQcmdZViewItem

The only part of the setup I might change is the windscreen. The metal zippers clang around and make noise which is an easy fix. I kinda have my doubts on how effetive the fur will be at stopping wind noise. I'm looking at the sennheiser and rycote windscreens to replace it with. One more thing... I have the Audio-Technica AT-835B and there is not enough room for a normal XLR to fit all the way and close the end cap. There is only about .75(3/4") inch left after the cap is on. I'm going to buy an XRL cable with a 90 degree bend to make the fit. Considering the price I paid I think this setup will work great. The full sennheiser setup without tax is around $800. If anyone is considering the $169 setup above let me know and I'll post some tests.

-Kev
 
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I know that this thread is VERY old, but whatever advice you can give me, would be greatly appreciated.

I'm embarking on a construction of my own blimp for less than £20-30. These are the materials that I'll be using:
- Bird feeder (£3) - to make the frame. Diameter 6cm
- 2 round tea sifters (£3) for the FRONT and BACK end caps
- 2 plastic jars with diameter 6cm (£2) - I will cut off the caps so as to make both end caps easily screwable onto the frame
- 300mmX200mm of Ultra fine mesh (£4) http://www.ebay.co.uk/itm/Fine-Stainless-Steel-wire-mesh-Insect-Reptile-Vent-Vivarium-/110876648077?_trksid=p3984.m185&_trkparms=algo%3DRIC.CFNPRP%26its%3DI%26itu%3DUA%26otn%3D5%26pmod%3D110876648077%26ps%3D63#ht_500wt_1077 I'M NOT ENTIRELY SURE IF THIS FINE MESH WILL AFFECT THE SOUND TRANSPARENCY. PLEASE HELP!
- Micro fiber cloth OR nylon stockings (£1)
- 6 Rubber bands (£0) - to hold the mic inside the bird feeder in X pattern
- 2 fluffy faux-fur lady's ankle warmers (£5) http://www.ebay.co.uk/itm/300698800758 hopefully these are good enough fake fur to block the wind. I will just saw the ends of these fluffies together. They are 40cm long, so should hold the entire blip pretty nicely.

So what do you think? Will it work? I'm especially concerned with a small (6cm) of the birdfeeder, but I hope that adding the fine mesh should suplement that. Or am I wrong?

Please help!
 
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