Encoding Tennis Sounds

[Alan Van Vliet]

I am in the midst of setting up a tennis instructional web site that to a great extent focuses on "sound contact".

Shooting with a XL1S, I have been filming with the sound recording coming exclusively from the on camera mike. At some point in time, I will need to get a recording system with directional mikes for recording sound on both sides of the court from a distance of about 45 feet.

Presently, I am working with this uncompressed sound from the camera mike (not bad) and wondering where to start with an encoder that will deliver realistic sounds.

I plan on using a Quick Time format for starters.

Any thoughts as to what would be a good starting point regarding compressors, setting, etc.

BTW, video clips will be very short, in the 8 - 12 second time frame for the most part.

Thanks in advance.

Alan Van Vliet

[Ty Ford]

Hi Alan,

Any relation to Don Van Vliet (Capt. Beefheart)?

Anyway, what audio perspectives or effects are you trying to create?

Regards,

Ty Ford

[Alan Van Vliet]

Hello Ty,

Looks like you are up bright and early. Good to have you with us.

No relationship with Don Van Vliet, as far as I know.

There is a certain quality (timbre?) to the sound of a well struck ball. Watching the home run hitting contest one year at the All Star game, one of the announcers commented that you can just hear the difference.

I would like to capture the most realistic sound I can so players can learn to emulate the sounds of well struck balls.

The sounds I am capturing from the on camera mike lack quality, depth, timbre I suppose. I have been recording in normal mode, 1/60th of second on a XL1S with default audio settings.

Settings in Premiere are 48000 Hz 16 bit with a 1/2 second interleave and compressed in QT with a IMA 4:1 encoder.

Future plans are for more sophisticated recording and have started looking into ornithology mikes and outdoor recording equipment. I will need to have at least two mikes, one for each side of the court, that will need to cover a 90 degree range from 10 - 60 feet. I assume directional mikes would need to be manned at these distances.

Any thoughts would certainly be appreciated.

Regards, Al

[Ty Ford]

Wireless mic, snaked down the arm of the player and either taped to his/her wrist or extended onto the racquet and taped to the racquet.

Regards,

Ty Ford

[Alan Van Vliet]

Thanks Ty, I'll give it a try.

The trick is going to be primariy picking up the sounds of contact, while minimizing player sounds, breathing, clothes rustling etc.

Any thoughts on audio settings and compressor for current sounds?

48000 uncompressed
16 bit
stereo

Currently using an IMA 4:1 compressor in QT Pro.

Regards, AL

[Ty Ford]

Well it'll be impossible NOT to hear the players move. You'd also probably need wind protection for the mics if you mount then on the racquets. A racquet moves pretty quickly through the air when striking a ball.

Hmm, maybe mount the lav on the shirt or shoulder of the player and see how that picks up the "whap."

Do you need the actual sounds or could you record the ball hit sounds separately and "foley" them in during post production?

If you foley them in, you could set up a mic on a fixed stand (like a shotgun) and have someone smack tennis balls over the net. Record that a fairly close perspective to get the "whaps" you want and then add them to the sound of the real hits. The trick would be to align them perfectly with the real hits (no problem with most nonlinear systems if you can zoom in very close to place the beginning of each sound) AND not add to much of the folied sound to make the resuit sound too hyped.

Of course, if this were for an action film, you also want to lay in a track of howitzer firings or at least an American Eagle handgun firing at close range.

Smiles,

Ty Ford

[Glenn Chan]

Any thoughts on audio settings and compressor for current sounds?

48000 uncompressed
16 bit
stereo

Currently using an IMA 4:1 compressor in QT Pro.

IMA will have trouble with transients like objects hitting each other. Not sure about tennis balls hitting the raquet as the sound may not be exactly a spike in which case you might be ok. If you don't have transients or lots of high frequency sound than IMA will be lossless.

If you have QT Pro you can use the "mpeg4 audio" codec instead, which is similar to mp3 except better compression. It offers better compression than IMA but needs QT6 to play back.

If you have money, the pro qdesign codec is also good (see the trailers on apple.com). That costs money though.

Use mono instead of stereo probably... most people can't hear stereo.

You could lower the sampling rate if there isn't much high frequency sound. You can shotgun your audio settings (export lots of different versions) if you truly want to optimize your clips. Probably 32khz is good as most people's equipment on computer can't reproduce the high frequencies too well, although 22khz may be sufficient for your material.

Check sound quality on headphones or really good monitors.

[Alan Van Vliet]

Ty, thanks for your input..

I do need the actual sounds from the different strokes. As every shot has a different sound, players learn to recognize the type of shots from the specific sounds and respond accordingly. (e.g. more spin - higher pitch, etc).

As we will be creating hundreds of clips, I really do need to record it one time live. When filming from a distance of 45 feet or so, I primarily pick up the sound of the players footwork (which is needed) and the sounds of contact.

Other sounds are minimal (clothes rustling, labored breathing - mine). Any suggestions as to what type of mikes would work for these purposes, I would need al least two as I will be recording both sides of the court at the same time.

I also plan to film some professional matches, and would love to be able to strategically place mikes to pick up their sounds (totally different sound) during play.

Thanks again for your ideas.

Regards, Al

[Alan Van Vliet]

Glenn,

I am now using the Sorenson 3 codec (per Rob) which also uses MPEG 4 audio. It has a AAC (low complexity) compressor set at a default rate of 96 k/bits per second.

I also took your advice and lowered the sampling rate. It is interesting, but at 32, 000 hz the sound is much cleaner, and more realistic, than at the uncompressed rate of 48000 hz.

Thanks for the suggestions. I am real pleased with the results.

Regards, Al

[Ty Ford]

<<<-- Originally posted by Alan Van Vliet : Ty, thanks for your input..

I do need the actual sounds from the different strokes. As every shot has a different sound, players learn to recognize the type of shots from the specific sounds and respond accordingly. (e.g. more spin - higher pitch, etc).

As we will be creating hundreds of clips, I really do need to record it one time live. When filming from a distance of 45 feet or so, I primarily pick up the sound of the players footwork (which is needed) and the sounds of contact.

+++Right. Foot noise will be be a major problem on hard courts. You may have to research what shoes make less noise, or use a clay court.+++

Other sounds are minimal (clothes rustling, labored breathing - mine). Any suggestions as to what type of mikes would work for these purposes, I would need al least two as I will be recording both sides of the court at the same time.

+++Ok, going out on a limb here. Sony ECM 88b mics (because they are small and because each mic has two diaphragms wired in reverse polarity to reduce vibration pickup) with pop filters affixed with clear tape to the handle of the racquet. Probably the mic should be right at the yoke, but the further out the handle it gets, the more swinging and the more subject to wind noise it might be.+++

I also plan to film some professional matches, and would love to be able to strategically place mikes to pick up their sounds (totally different sound) during play.

+++Again the court surface/shoe choice makes a difference. Hard courts make for squeeky shoe noises. My first thought would be to try two AT835ST in stereo mode, placed at shoulder height. Each behind a player and aimed toward the net. Or if you had the money, two Neumann RSM 191.

Hedge your bet by placing shotguns at but not on the net and aimed at each baseline. Record all mics to separate tracks.+++

Regards,

Ty Ford

[Alan Van Vliet]

Hello Ty,

Thanks for your response and great ideas.

As the weather allows, I will begin to do some experimenting. I do have access to some mikes that we can tape on the handles to see how well it will work out.

One concern is the amount of vibration that will come through the handle from a well struck ball, as there is a tremendous amount of force involved.

I'll post results as soon as I can.

Regards, AL

[Ty Ford]

<<<-- Originally posted by Alan Van Vliet : Hello Ty,

Thanks for your response and great ideas.

As the weather allows, I will begin to do some experimenting. I do have access to some mikes that we can tape on the handles to see how well it will work out.

One concern is the amount of vibration that will come through the handle from a well struck ball, as there is a tremendous amount of force involved.

I'll post results as soon as I can.

Regards, AL -->>>

Al, use the Sony ECM 88b lav to reduce the vibration as I mentioned above. There is an older AKG lav that is made this way, but they are the only two I know of that have the noise cancelling ability.

Ty Ford