A128 Transducer Question

[scottor]

Thank you for your knowledgeable response.
I fish the bottom between 250 – 450 feet and chase albacore tuna at 7 knots targeting to locater tuna at depth less than 150 feet.
Can I use the DSM 300 I have between my A128 and a chirp transducer?
What would give me the best performance searching the bottom at the depth I noted above?
• Use the CPT 120 direct to the A1128? OR
• Add a CP370 and a 600 to 1000 watt chirp transducer?
I am also strongly considering to retain the DSM 300 and the current Airmar transducer connected to my new A128 for use as a straight sonar view.
Thank you for your feedback.
Scott