Acoustically transparent waterproof fabric

[shenlung]

Good day. Is there any waterproof material that can be used to weatherize a horn speaker with minimal loss. I would like to mount material between driver and horn and then test for loss.

Thanks

[Cal Weldon]

Please tell us your application. I find your question and test procedure a bit confusing.

[shenlung]

Originally Posted by Cal Weldon

Please tell us your application. I find your question and test procedure a bit confusing.

The application is an array of speaker horns, The speakers consist of a driver made by B&C speaker and a horn that bolts to the driver. I would like to waterproof the individual drivesr by placing some waterproof/resistant material between horn and driver, or on the face (front) of horn.

We wish to experiment with different fabrics and test the horns to find out how much attenuation is created with the fabric installed. I am looking for suggestions of different weatherproof fabrics that also breath well to minimize acoustic attenuation.

Thad

[Cal Weldon]

Hi Thad,

I am still confused. The horn itself is waterproof. The outside of the driver should be also. The joint of driver to horn is waterproof with the gasket. Are you worried about water blowing into the horn? If so I would hang some speaker cloth at the mouth of the horn not at the throat as I'm not sure what you're looking for exists. I'm not Chemist but if air passes through it freely, water will too?

I think you better tell us more about how you will be using these so we can actually help.

[shenlung]

The front of driver which is not shown, has a fine screen type material. These are high powered and an array of them is being used in a hailing system that has electronically steered audio by changing phase between driver elements.
The idea is to replace the fine screen with some type of waterproof material with minimal acoustic loss. We already have a system developed that covers the whole array which attenuates ~3dB and is a pain to remove and reinstall. We want to squeeze every bit of power out of these. I am setting up an experiment to try different materials and measure the performance. I would just like to know what commercial fabrics are available such as Gortex etc that might be usable.

No the driver is not waterproof, here is datasheet for driver that is close. Actual driver spec is not published.
http://www.bcspeakers.com/CPD/produc...?id=0000000034
Horn datasheet
http://www.bcspeakers.com/CPD/produc...?id=0000000007

[Speedskater]

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GORE-TEX® Fabrics

[Enzo]

The problem is that air must flow freely through the fabric. You can get waterproof fabric, but all that means is that water won;t hurt the fabric. If you want to prevent water from going through the fabric, that is an entirely separate matter. Now you are asking for the equivalent of a screen door that won;t pass air. Anything you put across the throat of the horn that won't allow water through is pretty much going to seriously attenuate the motion of air, and thus your sound levels.

The mesh screen is there to keep out dirt and debris. Generally we keep water out of outdoor horns by not aiming them upwards. Or mounting a shield above them.

[454Casull]

Yes, if it's just weather, a rain+splash guard should work.

[Cal Weldon]

Or a cover over them for that matter.

EDIT: Maybe that's what you meant.

[mdocod]

A covered structure is the most logical approach to keeping things reasonably dry. Obviously, if this is an elevated speaker, it will be more subjected to wind that will drive precipitation into the horn on some occasions regardless. I think the best way to deal with this is some thin fabric that is reasonably transparent. The thin fabric will more or less halt any major driven ingress of moisture especially if assisted by a "roof" of sorts. Keeping every last bit of moisture out in all possible weather conditions is impossible outdoors. The fabric will of course become saturated, but that's no big deal, since it will still act as an effective barrier as it absorbs the horizontal impact of precipitation and eventually "drains" it downward. Any sort of thin screen or fiber mesh can more or less stop a large ingress of water in this application.

A "roof" structure over the horn may actually provide some desirable loading characteristics to improve SPL at the listening position.

Purposefully placing the speakers higher up, and aiming them downward would further help the situation if they aren't already up in the air.