Have you considered going wireless, using portable Bluetooth speakers and smart phone or tablet. We have removed all the older stereo equipment, the associated wiring. No need to cut new holes in the cockpit or companionway bulkhead. The speakers we use are the NYNE VIBES. They have true wireless pairing, more than enough volume and can be placed wherever you desire. We typically place them in cup holders in the cockpit table. They can also be placed on the cabin top with a little help from some adhesive velcro strips. The pic below shows the red and blue speakers in front of the pedestal guard.
Our H30C only had interior hardwired speakers installed by the PO. I was glad to see the automobile style CD/FM stereo and tangled wiring leave the saloon and cabin ceiling.
We also have a subscription to Spotify, with unlimited downloads.