Boombox Wall With Google Home? Advice Welcome!

Hello Fellow Boombox Fanatics! I saw this on reddit with no solutions, and had the same question as this person, so I am reposting it here with some modifications:

I would like to connect 8 boomboxes to my Google Home system, and would love ideas on how to do it.

The Goal: I have Google Home speakers, which play off my phone through Bluetooth. I want to be able to play the same song on all of my Google Home speakers, and these 8 boomboxes, at the same time.

The Current Plan:

1. Use a Chromecast Audio (example) (discontinued device that plays bluetooth music with a 3.5" output jack), connected to
   
   
2. a headphone y-splitter (example), which is connected to
   
   
3. two 5-way splitters (example), and, connected to each of those,
   
   
4. three 3.5"-to-RCA cables (example)
   
   
5. I'll hook each to the RCA line-in on the back of each boombox.
   

Plan B: Is there a Bluetooth-to-FM transmitter powerful enough so that I can get good sound quality? The one I have for my phone is pretty weak, and I don't think I can do this and also use the Google Home feature, so this is a distant second choice.

Is there a simpler, more effective way to do this? Will I loose a ton of volume by splitting the output so many times? I do not want to mod the boomboxes to be bluetooth.

Advice welcome!!!

Example (not mine):

 

I suspect the output split across several RCA cables will become garbage.
I have an FM transmitter that accepts Bluetooth or SD card, here it is:
Amazon.com: FMUSER 1W Low Power FM Radio Transmitter, 0-1W Adjustable PLL Stereo FM Broadcast Transmitter Set Long Range Coverage, No Battery, for Conference/Outdoor Drive-in Theater/Parking Lot Church: MP3 Players & Accessories

But that was 3 years ago, so maybe there's a better one now.......I haven't been looking.

 

WOOOHOOO!!!!!!!!!!!!!!!!!!!!!!!!!!! I think this will allow me to use all of my boomboxes at once! Thank you!!!!

 

Yeah we used it to drive a hotel banquet room full of radios.

 

I suspect the FCC might have had something to say about Amazon selling that. A colleague built something similar for a pirate radio station back in the 1980s. Thinking about the lower power versions which are readily available, the main limitation is probably the antenna. The optimum length for a 100MHz antenna is two 75cm rods configured as a dipole, which if you think about it is what boxes like the one bottom left in your photo have. Anything less won't work as well.

 

True, but the main selling point is portability. It's more difficult to carry a dipole antenna around.
It worked well enough at a distance of 40-50 feet, using only 0.3 watt.
Audio quality is the bigger issue. Frequent interference from cables, and the bass doesn't seem deep enough.

 

Forgive my question not related to the theme ... Some of them I know more or less ... others just don't .... you can make a list of boomboxes in pictures??

 

My point was that the FCC might have frowned upon Amazon selling such a powerful transmitter, in the same way that they would frown on someone selling mobile phone or GPS jammers. Apparently sixty one metres is the maximum permitted range for unlicenced transmitters.
https://www.fcc.gov/media/radio/low-power-radio-general-information
That should be enough for a Boom Room.

Alternatively devices like this are available if you can get them through customs
https://www.ebay.co.uk/itm/ST-15BV3-15W-76-108Mhz-LCD-Digital-PLL-stereo-high-power-FM-transmitter/273937751821?_trkparms=ispr=1&hash=item3fc7f65f0d:g:bEYAAOSw6iJe5z7M&amdata=enc:AQAFAAACgBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkY3FSd4Ad8xn3oRtkVexxrMckaf%2Bb%2BbrOETU3rgxswFUlkeOwb3QmIhSYay4V8Q4IOli2VgAiMNFA2UX2T7ddLQK93Bhisr039Iqq%2BPX5r1owe7%2B0IEw5sAaOs7FBHNf%2F6boDfox%2BC4CQX65XV8kTn1LVOSiG80WbKZibtDgIYgB%2FKFUxJ4pG4keuwqon53jEp6ScbYZwbJOyp1sYkw69UmHpg51nau0DcJtx0v5ZdHrpT%2BFQ6o%2BcRw9nOwZm31v3uDV%2FisgRs5nugvrwMhjLqWkY%2BKTQ4pJfIuiOXFrWcgzVAuZEuBJ93XYhF8rc3IUHh01G9Oc7oLxsxC7fiq7SfUEKVrXsxIRvTZz59dfdRMUQ7H1JVqKnEncUusXbka2QWO9tEVd1A9pHfPBlHHu8pzAJwOWbNGdV18Dl7pSK8rXEI%2FjIBVzOXpZKyde9ENpTKSq5BsZ05eEUp%2FwMeUbSyDfP93mICg9FomYO%2F%2B8t4YkXIXU0YS6N5mWrVGEWit3IoWDxCKkIriPzjQG6iLv4Bir%2B9g%2FVbJK%2BY2O6G%2F4zf6hdNLro8a1dfJvlBoDaHzsrva7x%2B7BvXq%2F8yqXbL%2FrCaJXG2Nejed74fF0BtsXgItSOmirL0QBZyXDHsfKaEH9ZpfECF0aS1%2BA0H3XsKhrVOkx55SZefl1OEmoSYNtK%2BTlg4EIPIHUbMAxLlgZiBfNWhluSiHtJ1wkY%2BkrjZ59FtsWhtUhyiipO0Yo%2F93HDQM6BZRKwy%2BzIWpOVbzZxFeS1okqEX%2F%2Bw%2B7J%2BAbIM5%2Bd4GoaBA2wlY2%2B8Vu4Wd%2FvuRHA%3D|cksum:2739377518212161860b7c0b440fbe6e1774cdd544f1|ampidL_CLK|clp:2334524
and have plenty of funds for a Lawyer if you need one.

 

beautiful.., FCC ?.. yu guys in the US? well i never... London Calling here!

yu guys got it hard... jammers .. really a no no? poor you! thas sad man... over here no-one would know what one was... same with stunners... a jammer though... man hours and hours of fun .. soooooo simple too...

 

soooo.. the boomcase girl surely deserves a mention for her tireless speaker care.

 

and the JVC RCM90

 

oh gad help me

 

handy for that quiet spell... yu know how annoyin it can be

 

oh yeah and channel changer infra red leds! the most fun yu can have with a mr noseys cam!...pixel slaughter at the flick of ya switch

 

oh man... thas a find ... thankyou... very cool seller. Im watching the vishay pots now yum...and a power amp for £50 ; with that beaut i’ll save messel mor’n a week in solder labour. Thankyou ..Its sll about prep buying from China isnt it just .. nice one Longman.
],)

 

Red Alert on KissFM ‘82

 

Boogie Boy

 

The Wiz

 

oh man i just saw the boxes.. i couldnt read any of it.., ok .. so ya want to deliver a hot signal to 8 machines from a single source... you should buffer your output. Itll struggle to achieve 8 inputs... but not at all if its buffered.
This is a really good project to enjoy getting into electronics with.. and if you do.. i’ll hold your hand, provide a cool circuit.. a BOM for the nearest provider to you. Youll also find that each input may prrfer a slightly diff impedance and volume/amplitude... again buffered circuits do exactly that. You will then be able to achieve the very best that temple of loud could provide... mismatching and volume diffs will mean a loss of bass and well
youll be pissed!

Product wise the AV guys will generate a off the peg number ...Kramer does an eight out from one in on mini jacks that the ‘bay often have for cheap £30-£50 (they sell a bit more new). Ask an editor pal for the one he pokkited a decade ago from a suite long gone... theyre very portable property and well... if ya work in audio yu accumulate problem solvers. theres a transformer option..great if yuve a buncha lovely bits of iron... ok to get four going .. gets expensive doing 8...
never been one to missup a challenge... er Nokia phone chargers... theres a draw full in most home in the kitchen... those 240v ac to 5v dc slate coloured psus contain a transformer that because of economy of scale is actually a great audio set-up step-down splitter and general help. yeah .. good iron fo free in just about every ones kitchen drawer by the door!
if ya funcy getting ta hands dirty .. im bang into sharing .., fk it ill build ya one if yu have a solder allergy!!!

 

ipods had a better legacy transmitter than a chromecast which comes with a heapa stuff yu dont want... itll fk with your everything until you smash it and reinstall all your software OS and bios everywhere .., Chromecast is pernicious. but hey im
a concerned citizen and it behoves us all to comprehend networks .. ports .. sudo’s and complex sopht that Chrome is.., its a complete remote operating system and its daughters are the same. We talking good audio everywhere with no annoying conflicts.... put ya big pants on man. Thas a job yu dont wanna toy with.