Sub woofer naive question day


I am a geezer and have had decent audio equipment for better than fifty years. But have never owned a sub woofer. What is the proper way to implement the speaker into a system with an integrated amp that does not have a specific sub tap? The amp has a line out and a pre out. 

hbarrel

Does the subwoofer have speaker level connections?  What type of speakers are you using? 

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Currently Spendor D9. But will be getting some Burchardt e50’s and their sub10. 
I believe the answer to the question is yes. 
However this will answer the question

Guess I cannot post a screen shot. 
In amongst the pictures is a schematic of electrical layout. 
https://buchardtaudio.com/collections/active-speakers/products/sub10