HDSI/Compact Transducer split to one unit?

I have a Gen 1 Helix 9 SI, and took my boat out for the first time over the weekend since I put my new motor on and updated my transducer set up. I have sonar skimmer and a HDSI transducer on the starboard side, running to a y cable/splitter to make it work. My new outboard likes to be trimmed in far enough that I have virtually no side imaging on the left channel in shallow water.

I still have my original compact SI ducer, can I run that on the port side with a Y cable with the HDSI on the starboard? I know the piezo is longer in the HDSI and you have to select that as the transducer in the setup, but will the unit know the difference if the left channel is running off a compact transducer? They run the same frequencies, so I am thinking that while my image may be a little less crisp on the compact/port side, that it will be a fair bit better than the nothing I have in shallow water right now.

I could just buy another HDSI, but my electronics are worth more than the boat they are riding on already and a 1436 with dual side imaging transducers on the back is a little silly.

I forgot that the compact transducer doesn't run 800khz, but I use 455khz 99% of the time so I suspect that as long as I dont try to run it at the higher frequency it will work. I wonder if I should switch the transducer selection to compact on the unit so I dont have the 800khz option. I doubt that there is a difference in the output to the transducer in 455khz, or a difference in how the unit would interpret the return between compact and HDSI selected.

It is definitely feasible to use 2 side imaging xducers along with the AS SILR Y Cable ... this cable has been discontinued but the newer M 9 SILR Y cable will still work for your scenario ... https://humminbird.johnsonoutdoors.c...splitter-cable

*Right SI, 2d and temp would come from the starboard mounted SI xducer ... so continue to use the AS SIDBY Cable and the 2d xducer connected to the starboard mounted SI xducer ...
*Left SI would come from the port mounted SI xducer ...

The HB core unit does not auto detect anything in an xducer except the temperature sensor .. so it will not know which side imaging xducers are connected ... the compact SI xducer will just have a little less detail than the Hi-def SI xducer ...

The compact SI xducer is fully capable of 800kHz ... the misunderstanding is that originally the compact SI xducer was packaged with head units that could not transmit the 800kHz frequency - thereby leading some to believe it was an xducer limitation - when in fact it was a head unit transmitter limitation ...

Rickie

Awesome, thanks for the detailed reply. I am glad that the compact ducer will run 800khz, I never ran it as I bought a HSDI back in the day and was thinking it would be odd to package a unit with a transducer that wasnt a match to its capabilities.