I don't have a Jensen Radio, but I did this to my Travel Trailer's radio by using the auxiliary input and a splitter. The main issue is getting audio output from the TV to your radio. Below is what I have used to get my sound through my radio speakers in the ceiling for the same reason as you stated (A/C too loud) but note this will only play your ROKU sound through the stereo -
see the second way you could do it so that your TV and ROKU all go through your stereo speakers which is the way I have mine currently. However this first way is how I have it setup in my living room so my ROKU goes through my Surround Sound System. (same principal).
This is how I did it.
First, you plug in your ROKU to the input side of the device above (the HDMI cable).
Second, you plug in an HDMI cabel into the output side of the device above and run it to your TV.
Third, my trailer already had RCA Jacks (Red and White cable ends) hanging out the wall for me to run audio between the TV and stereo (it came prewired like that from the factory). So I simply plugged my red and white (right and left) audio jacks into the device seen above which is on the output side which then ran to my stereo.
Fourth, I had to pull my stereo out and change the RCA jacks to the input side of my stereo (the auxilary input RCA jacks on the back of my radio), because the dealer had them installed as an output from the stereo ( I am guessing the dealer was thinking I might want to run audio from my stereo to my TV? Seems really wierd they wired it that way, but that's how they had it connected).
5th, we plugged in the power and listened to the audio now through the Stereo when it is set on auxiliary 2...
Note - this is the way I setup my Travel Trailer Below:
This is a second way to do it and I think the best way, if you want to hear the
regular TV and
ROKU through the
Stereo you need to use a different adapater as seen below. I like this one better as well because it has a volume knob on the converter too.
First, most TV's (including my own) have a
Optical Audio Output on the back of it (note many TV's that I have seen don't have an RCA cable type audio output unfortunately, but the majority
do have the Optical Audio Output, which is one type of input needed for this converter to work - see pics), so all you have to do is plug in your
Optical Audio Output cable into your TV and then
into the converter box above on the
input side. Also plug in your
USB cable from the
converter box to the
back of your TV to power it up (note if your TV doesn't have a USB then buy a cube that you will need to plug into an outlet to power the converter).
Second, plug in your two RCA jacks (Red for right and white for Left) which then go to your stereo's audio input RCA's on the back of the radio. These RCA jacks you see were hanging out the wall where the TV mounts, they came standard in the trailer so I didn't need to run them to the radio since they were already there.
Third, just
flip the switch to optical on the converter and you should have sound through your radio's auxilary channel
providing your RCA jacks are plugged in the back of the radio correctly. I say this because I had to
switch my RCA Jacks over to the input side of the radio for auxiliary (see pictures below).
This is how I have mine setup now and it sounds Great!
When your done just use some zipties to strap the converter to the back of the TV with its volume knob outward so you can adjust it if needed (be sure it is set all the way up + in the beginning so you are getting sound to your radio, then adjust if necessary).
I hope this helps and enjoy your sound!
A-Texan
