Please explain 2D/3D transducers working together?

So my new boat has a Humminbird transducer (2D) already glassed in the hull from the factory and I’m thinking about getting a 999ci HDSI for the console with the 3D transducer at the transom. So I know that the 3D transducer should only be used under 5mph or so, and the 2D transducer should be used when on plane. My question is, do you have to manually switch the transducers back & forth at the console or does the unit know when to use the 2D transducer vs the 3D transducer and switches automatically or are both transducers on all the time and the unit uses what it needs from both to display the best info on the screen?

The unit will do everything for you. There are ways to turn either transducer off by selecting connected transducer in the sonar menu, but not necessary. By simply scrolling through the various sonar displays, the unit will utilize the transducer best suited.

I should note that all this done thru a y-cable.

Thanks for the reply, that’s what I wanted to hear…I’ve always been a Lowrance guy, but wanted to take advantage of the already glasses in ducer and like Humminbird’s side imaging better than Lowrances.

Another quick question – I’ll get an adjustable RAM pivot mount for it on the dash, but how easy is it to quickly disconnect the cables and remove the screen during storage? Are all the cables individually connected to the back of the unit or do they attach to a quick disconnect type of connector?

I’m assuming the 3D your are talking about is actually the 360 model?

If so, and i’m not sure, but you can probably use the view button to select between viewing the 2d sonar vs the 360 vs SI, etc..

However, that’s 3 transducers connected to a singular unit. I have the quadbeam as well as the HDSI duecer, i have to run a switch as well as make the change in my settings.

As far as the cables go, the cords go into a quick disconnect bracket. That bracket can come off the back of your head unit in under 30 seconds.

Taking the cables out of the quick disconnect however will take you 5 minutes. Should be no reason to do that though.

Looking back at your post, you’ve got a CI unit, those aren’t 360 or SI or DI capable…So what’s this 3D transducer you talk about?

i edited my original post, Humminbird 999ci HD SI

That quick disconnect bracket sounds good, I’m just looking to quickly remove the unit whne traveling and leaving in storage.

I personally think lowrance has a leg up in sideimaging due to to the fact that the lss ducers have a dedicated down scan element whereas the hdsi ducer extrapolated the down imaging from the sidescan elements. Of course, that’s DI, not SI. The post above is correct, if you are using more than 2 ducers connected to the unit, you will need to install a ducer switch.

I’ll only use the Side Imaging ducer that will come with the 999ci HD SI along with the glassed in 2D ducer from the factory..

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I personally think lowrance has a leg up in sideimaging due to to the fact that the lss ducers have a dedicated down scan element whereas the hdsi ducer extrapolated the down imaging from the sidescan elements. Of course, that’s DI, not SI. The post above is correct, if you are using more than 2 ducers connected to the unit, you will need to install a ducer switch.

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FYI, the new ONIX with SI has its own DI ducer within the SI ducer so the detail on the di will be better than previous years.

The switch happens at the time you install the Y-cable. From that point forward your 2D sonar will come from your glassed in ‘ducer and your SI will come from the SI ‘ducer. It’s too bad the unit can’t be smart enough to switch 2D from one to the other based on GPS speed, but that’s not how it works.

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I personally think lowrance has a leg up in sideimaging due to to the fact that the lss ducers have a dedicated down scan element whereas the hdsi ducer extrapolated the down imaging from the sidescan elements. Of course, that’s DI, not SI. The post above is correct, if you are using more than 2 ducers connected to the unit, you will need to install a ducer switch.

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FYI, the new ONIX with SI has its own DI ducer within the SI ducer so the detail on the di will be better than previous years.

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Saw that in the onix thread. Thats good news, as that seemed to be the limiting factor between HB and lowrance.

I just bought a 999ci hd si and am mounting the supplied transducer to a dedicated deployment arm on the bow (homemade). I also have a transducer laying around from a few years ago that was a misrepresented purchase, it is a SHS 7W 3 D transducer. Is it of any use on the 999?

From what I’ve read, it doesn’t appear to be compatible with any of the newer units. Being a few year’s old, I would imagine it’s not gonna do you much good. Of course I can’t really tell what the purpose of the ducer was even for. Was it a DI ducer or more of a quadbeam ducer? 6 elements at 455khz doesn’t tell me much.

This ducer is for the discontinued 3D bottom contour units hbird 847 and 867. My concern is that if I try it, it would short out the head unit. On those units it displayed a 3D image looking like a wedge of pie showing humps and other contour irregularities. You can find these features in some offshore units produced for yachts $$$, they run a minimum of around $10,000 . this is only speculation, but I believe the next big “thing” will be 360 degree in 3D.

On your hdsi you can have both your hdsi and glassed in 2d transducers hooked into the $100 y-cable. The y-cable hooks to your unit. Leave the y-cable switch selected to the hdsi transducer. In the settings have your hdsi transducer selected. You are si, 2d, and si capable.

As I understand it, your bird will automatically display 2d from your hdsi until you flip the switch and change your settings to the 2d. Si and di won’t work.

My advice, tune your hdsi transducer location to work at high speeds.

The Hbird Y cable is only about $29 dollars.

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This ducer is for the discontinued 3D bottom contour units hbird 847 and 867. My concern is that if I try it, it would short out the head unit. On those units it displayed a 3D image looking like a wedge of pie showing humps and other contour irregularities. You can find these features in some offshore units produced for yachts $$$, they run a minimum of around $10,000 . this is only speculation, but I believe the next big “thing” will be 360 degree in 3D.

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This might be a better suited question on a site like sideimagingsoft.com where actual HB techs will answer your questions.