transducer sound

[dlampitoc]

Hi all,
Sea trialed a new installation today. dff3d and the diff-amp 2kw chirp. The 2kw chirp is loud in the aluminum boat. both transducers are in a sealed box. I have been told that commercial guys put sandbags on top of the transducers to deaden the sound. Is that the best option or is there a better way? Thanks

 

[Johnny Electron]

In all my years, never heard of such a thing. I would be worried about overheating the transducer. Sandbags? Really? That guy wasn't also trying to sell you a bridge, was he? No seriously, most people like hearing that the sounder is working correctly. If really that loud, you might take some acoustic material to the hull around the transducer to damping any resonation of the sound into the metal. I wouldn't suggest it be right near or on top of the transducer. Big transducers need cooling not only from the water but also the top areas to disperse any built up heat.

 

[Magnetron]

I talked with our commercial tanker folks and they have not heard of the sandbag thing. Rather, of all the sounds in a commercial ship, the XDR is the more soothing of sounds. Could you provide some photos of the installation, perhaps there's an option to add some dampeners.

Just a thought, :sail

- Maggy

 

[Deep Blue]

dlampitoc,

Can you tell me what kind of transducer that you currently have installed onboard the boat. Its is a wet-faced transducer, or is it a shoot-thru-the hull style transducer..? :questions

- Deep Blue

 

[dlampitoc]

We have a custom pocket mount with the PM111LH and the SS54 together. It is only the PM111LH that you can hear. The pocket is keel-shaped and sits about 75mm below the hull and the lid on the tank is 300mm above the hull. Perfect picture at 30 knots yesterday. 7metre Aluminum boat

 

[dlampitoc]

you don't hear it when you are underway, but when your drifting, can definitely hear it.

 

[dlampitoc]

maybe fill the box with propylene glycol to cover the transducer. Do you think that would absorb the noise?

 

[dlampitoc]

Johnny Electron, the guys talking about putting sandbags on top of transducers were professional lobster fishermen. Don't think they would be spinning yarns.

 

[Magnetron]

Johnny Electron, the guys talking about putting sandbags on top of transducers were professional lobster fishermen. Don't think they would be spinning yarns.

Just never heard of this happening. When I talked to the commercial guys, they actually said the sound of the XDR is one of the more soothing of sounds they hear compared to all the other noises on a ship.

In general, the only real concern over covering an XDR is going to be heat dissipation and keeping the cable free and flexible. Let us know what technique you used and how it worked.

- Maggy

 

[Quitsa]

I own a steel hulled commercial scallop boat that I don't operate myself normally but have been on from time to time. The possibility of hearing a transducer ping over the sound of a big low speed Diesel engine with dry exhaust, two generators, two hydraulic pumps, and the miscellaneous clanging and banging of the dredge chains etc etc is an amusing thought. Oh I forgot the loud rock music favored by the crew.

 

[dlampitoc]

got a reply from airman, and they said to insulate the outside of the box. Which I guess, is the same thing as packing sandbags around the box. Cheers

 

[Magnetron]

got a reply from airman, and they said to insulate the outside of the box. Which I guess, is the same thing as packing sandbags around the box. Cheers

Perhaps not quite sandbags, but some type of sound dampening is okay I presume. Unless you specifically asked about sandbags.

Perhaps if you put some of those sticky rubberized mats used to keep tools from sliding around a toolbox in and around the XDR tank it should dampen it some.

Anyway you can post a clip or video of the noise? :sorry

Just Curious, :sail

- Maggy