Can I use this line level converter in home?

I wasn't sure if this is the right place to post this for a response as I am new and not well versed in everything audio.
Anyway...I got the below line to RCA converter to use in a car stereo application but was wondering if I could use it for home as well. I have a powered sub that only has RCA input and a very old school Technics stereo with no dedicated sub out. I can hook the sub to an RCA out, but that sends a signal that does not vary with the volume control, so bass level is set only by volume on the sub.
On the Amazon site this question for home use did come up, but I dont really rely on Amazon replies. Some said you can, others said no because car audio is 4 ohms and home is usually 8 ohms for speakers. That made no sense to me at all. My assumption is that as long as the speaker level feeds don't send too many watts (40w per channel)then things will be fine. So if I have this hooked up to a regular home stereo and don't play it too loud, will it work? Or is it likely to blow up or just not work at all?
Thanks


Amazon.com: PAC SNI-35 Variable LOC Line Out Converter: Car Electronics
 
Hi nikg

Yes, you can use it. it will not blow up or blow something else up.

However, sometimes you get what you pay for, or don't get what you don't pay for. That's a pretty inexpensive unit, and the text in the listing, although confusing, seems to say there is a transformer inside. This would not be a power transformer, but one for signals. In theory these can be very clean and nice, but probably not for $8.99--you'll notice they don't promise anything above 10khz, so you're missing something. With a subwoofer, who knows, might not be too awful, but if you have it already, there's no reason not to give it a shot.

FYI, there are better speaker- to line-level converters out there that have a buffer/preamp stage, but they do need to ve fed 12vdc. I used one to create a volume-controlled line signal from my tv, and it sounds fine for that purpose.