Push Button Speaker Box with Built in FM Receiver - As presented at the Perth 2023 Mini

[Skymaster]

Popping when turning off power to an amplifier is common. This is nothing to do with your setup and is due to the way the capacitors in the amp discharge.
The same also can occur at power on. It's unavoidable.

Most hi home theatre amps etc disconnect the speakers really fast to avoid the power off pop. You can hear the relays clicking as the protection kicks in.

 

[Croydon Lights]

What about turning the speakers on and off instead of the amplifier
Add a cheap double throw double pole solid state relay to cut the speakers off actviated by the timer contact (NO) and you could then use the other contacts (NC) on the timing relay to turn the LED light on and off when the music is playing
Not saying this is right but another idea at the problem

 

[burnt]

another idea is to use a relay and resistor on the volume trim pot to lower the volume.

 

[Johnnyboy]

Ok. Can anyone help? What am I doing wrong? Button works. Relay works. Is led light on relay supposed to always be on if just when music is playing? Also, I’m still getting a popping sound when music starts and ends. Here is a picture

Good to see it's working, unfortunately as Skymaster said, the pop is from when the amplifier turns on and off.

I had this issue and i just delt with it last year. This year i will be making some changes to keep the amplifier powered all the time and use relays for the speaker outputs as Croydon suggested using an additional 2 relays.

I'll hopefully have something working in the next week or two and an updated wiring diagram that you can reference. Enjoy the pop for a few more weeks! Additional parts are only about $6

 

[Skymaster]

Honestly - leave the pop there. No one will notice, and those that do will see it as a "hey, the button did something", especially if it's between songs.
Putting a delayed relay on the speakers for power-on means that they wont have sound for a second or two after hitting the button which may be a bit confusing.

Or as mentioned, leave the amp running all the time; that's probably the better option, especially if you power down your show outside of hours anyway. It'll be better for the amp.

 

[Katekate]

another idea is to use a relay and resistor on the volume trim pot to lower the volume.

the thing you could do with that is have it at a very low volume, then the button increases it.

 

[aimbrunone]

Thanks so much everyone for the suggestions. Not sure what my next plan will be. I may just leave it for this year. This is my first year doing a show and I’ve already done more in this first year than I originally planned! lol.

 

[Lindsayr]

Hi Johnny,

Thought I'd share my variation of your project. Decided to place the pi and fm transmitter in the same box as well as a small smart receiver. So far it works well (as long as transmitter is in low power mode).

Thanks for all your effort in putting together such in depth details!

Lindsay

 

[Johnnyboy]

Hi Johnny,

Thought I'd share my variation of your project. Decided to place the pi and fm transmitter in the same box as well as a small smart receiver. So far it works well (as long as transmitter is in low power mode).

Thanks for all your effort in putting together such in depth details!

Lindsay

Thats awesome! Nice way to combine everything in one box, looks like a reasonable amount of room to work in as well. Nice idea to add a smart receiver as well. Gives good use of all that power.

Glad I could help a little

 

[Croydon Lights]

Hi Johnny,

Modify the ciruit to use the timer NO contact to run added an double pole relay to cut output from the amplifier to speakers and at the same time ran a 4 core to the button which was used to turns off the light when the speakers are running and lights up when the speakers are off from the NC contact off the timer relay
The amplifier is always on and turn off when I shut the show down at the end of the night
It works well with no pop
I only cut the postive side of speaker wires with a double pole relay

 

[Rossjb]

I'm currently working on a variant that uses an ESP32 controlling the relay.
The idea being that the ESP32 can run the timer function but can also host a web application to configure it.
This allows me to disable the button remotely or let the music run indefinitely (for when I'm out there enjoying the lights).

I'll update more here later but here is a link to the code if anyone wants to follow along or contribute

GitHub - RossBille/push-for-sound

Contribute to RossBille/push-for-sound development by creating an account on GitHub.

github.com

 

[Lindsayr]

I'm currently working on a variant that uses an ESP32 controlling the relay.
The idea being that the ESP32 can run the timer function but can also host a web application to configure it.
This allows me to disable the button remotely or let the music run indefinitely (for when I'm out there enjoying the lights).

I'll update more here later but here is a link to the code if anyone wants to follow along or contribute

GitHub - RossBille/push-for-sound

Contribute to RossBille/push-for-sound development by creating an account on GitHub.

github.com

Love the idea!

 

[Hoodlum]

Some good options here
Something i never got to document on my 2023 build
I went with the button (with long 12v wiring to front fence ) triggering the timer relay which controlled the speaker output directly - there were some caveats i had to deal with using SP relay, like going mono, but it got me through the season ok.
I will do similar this year but with a DP relay (actually 2 SP relay's) so expect stereo!

if time permits i might just investigate the esp control of the speaker relay similar to Rossjb (i like this idea)

time to update my 2023 build log haha

 

[Johnnyboy]

New Update!

EDIT 2/09/2024: Don't buy this amp, try something different. I tested it out on the weekend and it was terrible! Ended up buying a second hand 2 channel 240v amplifier. Waaaaay more power and clarity is fantastic at high volumes, I've now modified the box for a third time to function as just a time delay relay box rather than all in one box. Will update the wiring diagram in the near future.

I’ve been promising it for a little while now, but I have now updated my Push Button Audio Box, and ready to share the write up.


What’s wrong with the old design?
Nothing, but I wasn’t a fan of the ‘pop’ sound of when the relay was triggered and the amp made a sound through the speakers. This new design added in additional relays at the speaker output level so the amp stays on the whole time and no ‘pop’ sound! Yay!

The second reason is that my push button control box decided to take a bath……So what better time to try something new update the design.


New amp?
The original amp was quite good (120w x 2), and didn’t really have complaints, but the clarity wasn’t quite right over a certain volume so I wanted to try a larger (400w x2 2) amp. I haven’t tested it full out yet, but it does sound a little better. Time will tell if I made the right move.

Shopping List
Most of the shopping list remains unchanged from the original list, here is a list of things from the new build.

Store	Item	Number	Cost	Total
AliExpress	DC Power supply Plug Barrel 5.5x2.1mm (I bought a 10pack)	1​	$ 6.25	$ 6.25
	https://www.aliexpress.com/item/1005005992365932.html
AliExpress	AK380 Amplifier	1​	$ 33.63	$ 33.63
	AK380/G8/AK370/AK270/AK170 800W 12V Home Car Hifi Power Amplifier Stereo BASS Audio Amp Speaker Class D Car Home Sound Power Amp - AliExpress 44 Smarter Shopping, Better Living! Aliexpress.com www.aliexpress.com
Temu	1 Channel Relay - 12V	2​	$ 1.96	$ 3.92
	https://share.temu.com/I09r5Etg9IA
AliExpress	DC Power Plug - 90Degree 5.5x2.1mm	1​	$ 5.06	$ 5.06
	https://www.aliexpress.com/item/1005005732345958.html
Temu	A Mini DC-DC Buck Step Down Converter Board 12-30V to 5V	1​	$ 2.20	$ 2.20
	https://share.temu.com/FwQeyMywzjA
Temu	3.5mm to 3.5mm Audio Cable with 90 Degree Elbow	1​	$ 1.87	$ 1.87
	https://share.temu.com/NsAjfKy76wA
Hanson	BOX-290X190X140	1​	$ 34.00	$ 34.00
Electronics	https://www.hansonelectronics.com.au/product/box-290x190x140/
AliExpress	Various Quick Wire Connectors (Approx price as I had a lot)	1​	$ 5.00	$ 5.00
	https://www.aliexpress.com/item/1005003870395163.html
	*Prices as of 25/07/2024 (all prices inc shipping in AUD)			$ 91.93

Photos of all the items.


Updated Wiring Diagram



Push Button Wiring


Tips

• For the Push button wiring, use a standard 3wire pigtail at the button and into the box, it lets you then use standard extension cables and control the length as you like it. It also lets you separate the button as its quite awkward with a long wire.
• Use a standard 2wire pigtail for power in, same reason as above as you can use standard 2core extension cables to place the box where you want it.
• Lay everything out and plan your cable runs. I ‘adjusted’ many many times
• Allow a little more room from the outside of the box into the connector. It was tight!
• Using some plastic spacers with hot glue to hold the aerial wire in place worked really well. Doesn't interfere with the lid closing at all.

Lessons Learnt

• The Amp I ordered had a built in FM receiver, so I originally thought I wouldn’t need the old one. However I found that when the amp lost power, it would default back to the AUX in and not FM. It also didn’t hold radio station channels when powered down. Very fortunate it defaulted to AUX in otherwise I would have needed to rethink the design.
• I could have used a 2channel relay rather than 2 x 1channel relay but it’s what I had on hand.
• The 1 channel relays I did have are the old style with pins sticking out rather than screw connectors. I would recommend the screw connector type as most people don’t have the 3wire connectors that I do from a previous hobby (thanks RC Heli days!)
• I had to use a few wire splicing connectors as I only had 1:3 on hand. If I had a 1:5/1:6 it would have been simpler. Use what you have I guess.
• The wire splicing connectors I had are big! Needed to put a spacer on the bolts that connect to the case.
• The amp over the case bolts……didn’t feel like re-doing it all so the bottom plate is only held in with 2 screws rather than 4. Woops!
• I went a little overboard with trying to keep it neat. Neat does not make it work any better! OCD kicking in for sure.

The Pics!



Thanks all and keep sharing your push button creations. Really nice to see so many people benefit from the thread.

 

[Skymaster]

Thats a much better design switching the speaker lines.
I do rate AliExpress and their dodgy advertising. 800W from that amp, from a 12V 3A input Someone needs to go back to school and re-learn their times tables