Hi all. I tried googling several hours, and came up with some info, but not really enough. I'm interested in creating a parabolic microphone, or "collector", primarily used for high school football videos. I am in context of creating a clone (won't be as good, but hopefully will work) of the Klover 26". I found a 32" dish online to start with. I looked at the Klover details as far as mics, and see that they use omni directional mics. Also learned that Countryman EMW mics will be a better bet?
https://www.bhphotovideo.com/c/product/327257-REG/Countryman_MEMWP4S05B_EMW_Omnidirectional_Lavalier_Microphone.html

Also, from what I have been learning in the past week, I'm going to try and state the procedure for how I am going to record the event .If I am wrong, please feel free to correct me. My head is still kind of spinning from learning a lot of audio tech in the past week.

For the press Box: Plug a Tascam DR40 into the pa system, this way I can monitor the input level and set a safe level on a sound check.

For the Parabolic mic set up (with Assistant): Plug parabolic mic into the Tascam DR40 to control audio input and so my assistant can hear what it is picking up. A Rhode Wireless Film maker system will be joined with the Tascam DR40. I would then have the receiver on top of the camera, converted into one of the XLR connections. (Canon C100). I'm using wireless to prevent tripping hazards.

Thank-You guys and gals for your information here!
-Paul

Best of luck. My experiment some years ago soon had me heading back to shotguns. The biggest problem was nothing to do with the dish - it was the pan and tilt system. I was using a re-purposed satellite dish with the mic at the feed point - as a mic for speech, it worked rather well, but it needed accurate aiming and that was my problem. Now I realise why some commercial systems use transparent dishes! My aluminium dish had to be forward mounted on the heavy duty tripod to clear the legs, and then I ended up with an extension going the other way that needed a gym weight to counterbalance it. This meant even more weight and I had to use an elderly Vinten TV head to be able to balance it out and be strong enough. I built sights at the side so I could see the way it actually pointed, but neither me or my colleagues could keep up with fast action. It was also prone to wind, solved fairly easily, It was far too big to transport easily, being 3ft diameter, and took up far more space than it deserved.

With careful aiming it was pretty good, once you remove the low frequencies - but now I use 4 spaced shotguns, in hairy covers on short stands. You don't get the same result, audio wise - less conversation and words, but with the dish, you got some wonderful clarity, but nothing else, so you still need general mics. The dish sound is a bit strange, as I'm sure you've found - on headphones it's a bit disturbing!

I wish you luck - we did a few outings and then scrapped it for practical purposes. Far too much effort.

Another probable issue is, most feeds from a PA system are Line level. The microphone from the dish (or other) is Mic level; All the external L& R inputs on the DR-40 are switched globally, so you can't have one mic and one line w/o some sort of external matching device... be it a pad or mixer..
FWIW, my usage of parabolic dishes (expensive pro models) were enlightening... but didn't sound very good. YMMV.

Not sure I am following how you intend to do this? If you are recording the venue audio (from the press box) on your DR40, how do you propose to also use the DR40 down on the sideline for the parabolic mic operator to hear what he is aiming at? Or do you have TWO DR40s? Or do you have a press feed down on the sideline?

If you are using wireless to feed the parabolic mic into your camera, why not just use another wireless to feed the venue audio? Recording to a separate recorder just forces you to do a lot more work in post-production editing.

I would use something like a Rolls PM50 so that the parabolic mic operator to hear what he is doing. We are assuming that you have a person down on the sideline actively aiming the parabolic mic.

I would have 2 Tascam Dr40s. The reason for not havinng a wireless on the press box Tascam is distance. I think it may be too far for the signal to travel. I probably should just go with senheiser for strength? My assistant and I would be down on the field next to each other. So a 2 or 3 channel mixer would be needed to convert the signal coming from the tascan from the press box?Thank you for your help

I think it may be too far for the signal to travel.
Unless your high-school team is playing in an Olympic stadium, that does NOT seems like a reasonable assumption. You should at least try it.

What are you doing for ambient (crowd) sound pickup? A tight pattern from the field and a direct connection to the venue system will leave you with a pretty dry sound track if you have no audience reaction.

Part of my recommendation depends on how long the recording must run on battery power, and/or if you have a battery-powered mixer or AC power at your camera position.

If I was doing this most simply but hopefully effectively, and the recording time was short enough for safe battery power, I would use two wireless systems feeding the camera like Richard recommended. One from the parabolic mic (or whatever you replace the parabolic with if it becomes impractical), and one from the pressbox feed.

For backup I would also record the pressbox feed in the pressbox using one of your DR-40's but hopefully not need it.

For ambient sound, I would mount your other DR-40 on a stand near your camera and put good wind protection on it. Slate it and the camera together occasionally both visually and with audio while the parabolic is nearby during a break in the action. Your mic operator would use a separate monitoring device like Richard also recommended.

Have a mic mounted on the camera but not connected. If you have a total failure of one or both wireless feeds, plug that mic into the camera.

I'm happy to hear the Rhode system might be able to handle it, I probably did over assume it. As far as the live audience, I was thinking of having 3 mics, all in front of the grand stands on the ground, evenly spaced out. The mics I was thinking of using are cardioid condenser microphones and then a mixer connected (on the ground too). Would it be best to have the pa directly hooked up to a wireless sent directly to the Mixer along with the 3 mics for the crowd (wired to the mixer), and parabolic mic having a wireless then sent to the mixer as well? So Pretty much having the mixer as a main hub, then having a wireless (A Y splitter to send both audio on seperate wireless units) to both cameras as one?I'm probably making things more difficult than they should be. I do like the idea of recording the pa announcer as a back up and using the second tascam for recording the crowd! I do have outlets available for power supply.Thank-You again for your help!

Remember that any mixing you do from multiple sources down to a limited number of recording channels becomes permanent when it's recorded. Once it's mixed together you can't undo that.

Since you have two cameras, I would record the PA feed to channel one of both cameras. With one of them mounted close to the audio mixer so you don't have to use wireless.

Having the PA feed on both cameras makes it very easy to sync them later.

To reduce mixing of multiple sources, I'd put the parabolic on the second channel of the camera closest to the mixer.

I'd put any ambient mix onto the second channel of the second camera.

That way you have 2 identical PA feeds for sync and backup, a separate parabolic track and a separate ambient feed. You haven't permanently mixed anything that's critically important. If after the event, you don't like your live ambient mix you did with extra mics you could probably get by with the ambient recording you made with the second DR-40.

If you are sending the PA feed wirelessly to the audio mixer, I would use the first DR-40 to record it in the pressbox as a backup, it's too important a feed to lose and it probably won't sound good if you are forced to pick the PA up solely with your ambient mics.

I'm not familiar with the Rode system. Most of the other wireless systems (Sennheiser, Sony, Shure, Audio-Technica) have pretty good range outside with their UHF systems set to High transmitting power. Some of the 2.4gHz systems aren't designed to go as far. You'd have to test it, preferably at a game the week before so it's a realistic test in that RF environment.

Other considerations are the construction of the pressbox and its windows. If it's old-school industrial construction it might have wire mesh in the window glass and that would be a serious problem for transmitting wirelessly unless you can get the transmitter outside for example.

Erm, if I may stick my nose into a subject I'm not 100% comfortable with:

This scares the bejesus out of me:

" I am in context of creating a clone (won't be as good, but hopefully will work) of the Klover 26". I found a 32" dish online to start with."

Do I take it we're, no, you're, attempting a CBS or SKY live event with a Sunday School budget?

Won't fly, can't fly. Period.

Unless you have done this 20+ times before and have ironed out every wrinkle, every glitch, every weak point and every "this will sink the entire bloody ship if we fuck up" event, don't even try it.

The Klover 26 was found way too impractical for stadium sports, which is why they developed the much smaller systems, a 32" would be utterly impossible, even for an experienced operator, which it is doubtful you have.

Do not attempt this.

Keep it (much) simpler or fall flat on your face.

Another question: Who's paying for all this?

If you're a multi - millionaire, good luck, you can probably afford all these little bells and whistles being suggested (the bit about trying to out engineer Klover says it all), if you're an ordinary shmuck like the rest of us, where's the revenue stream to pay for it?

This is college (er, high school?) football, nobody pays squat for coverage of that.

I may be becoming terminally cynical in my dotage, but this simply reeks of over-reach, pure and simple.

My two cents from a hardened campaigner.


CS

Getting quality amateur audio recording is not easy or cheap. There are a variety of on-line sources for moderate cost parabolic kits. Aiming and practice using are going to be key issues once a system is build. The Klover 16" might be a better model to emulate than 32". The size is more manageable, and the nominal effective range should be adequate for football.

In part it depends on your budget. Klover offers a 9" as well for camcorder mounting.

Wildtronics, LLC - professional parabolic microphones and more (http://www.wildtronics.com/index.html#.WNUtjWe1vkg) is one source of kits and parts. Their 22" might be interesting, and they offer an economical 11" as well.

I suspect a ref's whistle blown at the focal point would be pretty noticeable <G>.

Does this help - radio link from a shotgun on the touchline.
Shotgun v camera mic on Vimeo

Videomaker ran a how-to-make-one article a few years ago:
https://www.videomaker.com/article/f20/17144-how-to-build-a-parabolic-mic-dish
But I suspect the improvised things they used for reflectors were not very very good.

Shotgun mics basically reduce sound pick-up from the sides and back, But effective forward sensitivity is limited by their self-noise. Parabolics do offer real gain based on the dish size and do not have the inherent noise floor issue of shotgun mics. Accurate shape, positioning of the pick-up, and aiming is essential.

In some cases parabolic mics are used in football primarily to pick up "sounds of the game action", not vocal audio. Everyone knows your not going to eves drop on the huddle.

So....if it was me I would skip the parabolic effort and expense. I would watch Bull Durham one more time to get ideas about how they faked baseball audio. I would prerecord a bunch of nasty sounding hits and other things and use those prerecorded stingers to blow away the audience. This is high school football we are talking about. It is not ESPN. Have some fun with it it!

Steve

Videomaker ran a how-to-make-one article a few years ago:
https://www.videomaker.com/article/f20/17144-how-to-build-a-parabolic-mic-dish
The first photo in that article brings to mind the old saying: Garbage in, garbage out. Originally coined in regard to digital data, it applies to audio as well.

How will most people reading that article work out if their bin lid or saucepan is remotely parabolic? At best, some of those products are merely shields from sounds coming from other directions. Gain from proper dishes with a real focal point are good, but moving the feed point on a real dish just an inch or two wrecks the performance, so using a plastic lid is totally random!

Best way to get audio from the heart of the action is to do what we do on Rugby and put a radio mic on the ref.

Of course you get all the decisions too and even some choice language but it actually does add to the game coverage if mixed in correctly.

As for parabolic mic's they all sound dreadful with narrow bandwidth and tend to be only used to record birdsong in the UK, we tend to use 416 and 816 mic's on most sports in the UK.

As a sidenote I tend to find the NFL audio for TV very tiring to listen to and they seem to add huge amounts of gain momentarily to get the kick off and the crowd is distant and very mushy and ill defined.

It all ends up as just noise most of the time with little definition and after sitting on the end of it all for up to 7 hours of coverage at work it is very exhausting.

The Videomaker article provides a point of departure, and some ideas for a low budget experimenter. It was not suggested as an authoritative source. It is up to the end user to decide whether or not it meets his/her needs. It certainly will not meet the needs of networks, except perhaps as a way to do it in a stealth-mode.

I have played with home-brewed parabolic arrangements. To render a normal audio frequency range comfortable for the human hearing requires reflectors larger than are practicable to use.

For a "must get it right" mission critical event coverage, as I have myself been previously counselled here, you owe a respect to the people who have commissioned you to make product for them. The advice of others here suggesting options besides a parabolic arrangement are worth considering seriously.

There's nothing wrong with recording from a parabolic source to its own dedicated audio channel so long as you have other audio going to its own channel. ANY air movement is going to be a deal killer. Please DO NOT contaminate your audio with a parabolic source going into a live mix.

All that lamentation just said, there is an arrangement which is easy to construct. It uses a fairly common pay TV satellite dish made of powder-coated steel. The dish is not an entire parabola, but has been muchly cropped at the sides, has an offset feed relative to the total dish size but is a faitfhul parabolic segment.

To make it work as a mic reflector, the dish has to be inverted on its four-bolt mounting frame. In use across a flat field, the dish front rim is inclined upwards so that the feed post is relatively level to the ground.

The best mics I had in my kit I found to be lavalier type, Sony ECM55B. It was a simple task to cut some soft foam to fit in the space where the transponder fits to a bent post. A small hole was cut in the foam to support the mic and insulate it acoustically from the metal frame.

Mounting the dish to a tripod is not hard but preventing handling noise clanking its way around the dish into the mic is another matter.

Fixed adjustment of the original hinge bolts and clamping bolts can be made easier by replacing the existing fasteners with bolts, adding flat washers between all rubbing surfaces and using wingnuts.

A sandwich of flat washers and spring washers under the wingnut is desirable to enable tensioning of the fasteners without firming down hard. This enables trim adjustments of the angle to be forced against a light friction without the dish flopping freely.

To mount the dish on a conventional camera tripod required a short metal pole with a flat base to match the tripod baseplate with a tripod screw thread tappen into the bottom. There needs as mentioned above in previous posts, a rear countermass to balance the weight of the dish across the tripod tilt and pan axial centres.

You also need some sort of sighting device which can be as simple as a piece of PVC tube to look through or an old telescope gunsight.

My version shown in this video clip was temporarily mounted on a garage light stand.

As well as the concentration effect of the dish, the signal from the mic was fed and heavily amplified via a Sound Devices MixPre to a Zoom H4n recorder.

PARABOLIC TEST - EARLY MORNING BIRDS. - YouTube

Confused - I get something like that with any microphone in my garden? The point is the increase in wanted sound compared to unwanted sound, and there is a hell of a lot of ambient background noise. How about pointing it at yourself 30m away and speaking in a normal voice? Honestly - nothing in that clip allows a listener to determine anything whatsoever without some kind of comparison, or images, or structured test.

Here's an alternative
http://www.limelight.org.uk/Birdchirp.mp3
Is it a dish, a cardioid or an omni? Impossible to tell - it's actually my iPhone.

I'd genuinely love to hear your dish work - so I am not being picky, but the test isn't a test without some kind of base line to run it against.

Paul.

I don't take your comment as being picky and my unthorough experiment as such might be explained as follows. My recording is not the paragon of perfection and was never intended to be. My comment I have "played with" home-brewed parabolic arrangements discloses the lack of depth in my experiments.

I recommended against the use of a home-brewed parabolic arrangement for a high value professional task and posted this example purely for curiosity interest and for folk taking responsibility for their own experiments to know a few build methods.

I know you can gain the hell out of modern microphones and pre-ampliers to achieve a similar sound. What you were hearing was the mike zoned in upon the small bird in the tree canopy some 50 metres distant.

The narrow band of pickup from the reflector also picked up some crows furthur distant across the road and the highway traffic 2km away down the valley. It was aimed through a forest and there would be some return of off-axis sounds from tree-trunks and leaves.

The dish crispens high frequency sounds and is most pinpoint with them. The lower frequencies from other directions can and do penetrate. I was receiving more ambient background noise when using a Sony C74 directional on the same subject with the same gain levels.

With this dish, the sound of a ticking alarm clock hanging in a rose bush can be zoned in from about 20 metres against ambient background noise.

With a much larger complete satellite transmission dish, the clock can be zoned in from about 60 metres and a fuller sound can be drawn in. However the larger dish is very impractical to use.

My intention with that dish was to aim it to a particular fixed point an aerobatic aircraft was going to fly into and record the unique sound of torn air when the pilot executed an "avalanche" manouvre.

That is not a parabolic microphone it is just a metal sat dish designed for video HF transmission signal used with an ECM mic in front of it.

The whole point of a parabolic mic is that it focusses the sound waves to a single point and as sound waves are a lot shorter than video RF waves the dish needs to be a lot more curved.

As Paul has said you are not really getting any benefit from this set-up over a traditional short shotgun and you might as well just take any lump of metal or wood and use it as a "reflector" . Note your body would probably do just as a good a job and you are not actually creating a parabolic anything and just rejecting certain sounds that are 180 degrees from the mic.

The other aspect to a parabolic set-up is that the focal point of the hot spot is phase coherent, just plonking a mic in front of a lump of metal that is full of holes anyway is asking for trouble.

Sorry to sound (no pun intended) negative but this is akin to just plonking a jam jar on the front of your camera and hoping that you will get lovely pictures.

OK fun to play around with but this is just re-inventing a wheel that is actually rather square.

;0)

Gary.


I do not disagree with you. The profile of the sat dish is not an entire parabola that is true. It is a very small area out of a true larger diameter parabola.

It does not have the apparent acoustic gain of an entire parabola but it does have a fine point of acoustic focus which is at the same position where the original waveguide and UHF pre-amp was positioned.

It does not "seem" to have the rear cone of pickup some shotgun mikes have so airiness of overhead tree canopies and back echo from tree trunks "seems" to be less when chasing birds and frogs. To be sure, a precise comparative test would have to be done.

"---- and as sound waves are a lot shorter than video RF waves the dish needs to be a lot more curved." = true.

Acoustic at 3000Hz wavelength = 0.1146m
Acoustic at 800Hz wavelength = 0.43m

Foxtel 700MHz wavelength = 0.429m

The force of the barrier of denial is strong in me. The sat dish was an experiment. If one does not have a decent low-noise shotgun mike, then the Foxtel dish is of some use.

However, a parabolic dish is not something I would use on a sports ground in preference to having the umpire wired with a radio-mike or a good shotgun mike aimed at the action.

A full spun aluminium parabolic OB dish I have is about 1.5M in diameter. It is much more effective as an acoustic reflector but also too much of a handful to be useful.

The little shotgun mike I have did not pick up the ticking clock in the rose bush but my whistling nose whiskers could be heard when I forgot to hold my breath.

Don't get me wrong it is always fun to play around with sound and as a recent purchaser of a very nice analogue allen and heath CMC 32 console for less than $200 it puts my $500k Calrec Apollo into some perspective as it still sounds better but in my 37+ years in TV and film I have never ever actually used a parabolic mic and when I hear the incoming sound from NFL Fox and CBS coverage for SKY UK I know why as it just sounds dreadful.