Chests? They sound as though they've got bad ones (7)
I believe the answer is:
coffers
'chests?' is the definition.
(coffer is a kind of chest)
'they sound as though they've got bad ones' is the wordplay.
I cannot quite see how this works, but
'bad' could be 'off' (I've seen this before) and 'off' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for coffers that I've seen before include "Treasury funds" , "Treasure chests" , "Strongboxes" , "Treasury boxes" , "Financial resources or money boxes" .)