Home speakers with car receiver possible?

You can add a resistor, sure. All it will do is turn the volume down. Much easier to just turn the volume down I would think. 

The receiver will be fine with those speakers. Just hook em up and enjoy. There is nothing like the sweet sounds of nature washed out by car audio. Of that I am certain. Why else would people drive to the woods but to turn it into what they had back home?

I appreciate that you have your own opinion. I think a bit of quite classical music in the evening or being able to hear a news broadcast is relevant and valuable, for me anyway. Cheers

If you read the earlier message, ,and don’t get the sarcastic humor, maybe I need to buy you a Modelo?

  Yes, that will work fine. 
Smile more, silly. 

I have been thinking about perhaps installing a set of Polk Atrium 4 speakers. These however indicate 8ohm resistance. I think the JVC car receiver (KE-X840BTS) would prefer lower ohms?
What can I do?

8Ω speakers are OK to connect to the JVC car receiver, but it can't provide volume level as loud as 4Ω speakers, you can turn the volume control up to compensate.

I’m sure 4 ohm speakers will push the head set to it’s max. The 8 ohm speakers will be a bit quieter. No resistors needed. You have the installation instructions? It will give you the minimums and maximums ohms.

Need an A/B switch for inside or out.

I suppose you could use the fader option. Fade the outside to ZERO for the inside to work on it’s own, otherwise all 8 vs 4 inside.. OR the A/B switch option..

If you’re going to do a marine install remember the ground.. Keep it large enough and every joint use sealing butt connectors. Don’t cheap out.. 12 vdc can drive some very good home electricians nuts. Remember marine depends on the actual wire to carry the ground.. Don’t bond to a common lug or frame marine requires a ground for every circuit and that circuit directly to the 12 volt battery ground.  Marine requires that.. automotive does not.. the frame is common in automotive along with the firewall, to the ground lug.. it’s different..

Low voltage with potential high amperage and green connection don’t work well.. That can happen in one season of setting.. Use protection on the DC supply, keep battery terminals clean and treated with corrosion inhibiters and contact enhancers..

50 years of cleaning batteries. I’m pretty good at it.. :-) LEAD Contacts... NoCo is one of the best.. Red terminal pads and red contact spray.. Wipe off the excess, don’t drench it without wiping after. It’s good from -80 F to 200+ F

Enjoy