Adding sound effects to a layout

[teedoubleudee]

Looks that way.

Was a little disappointed with the volume so I’ve ordered a couple of lower impedance speakers as well. I tried to increase it by increasing the sound file volume but I could hear the clipping.

Possibly a mismatch in the speaker impedance. They can vary between 4 and 16 ohms in normal speakers but know nothing about these cube thingies

[Nokonium]

I had an 8 ohm that should give out about 2w, the 4 ohm should produce about 3w. That should be enough to have it loud enough without appreciable distortion.

[Nokonium]

Wired up the new speakers today

https://smile.amazon.co.uk/Gikfun-Speak ... ics&sr=1-3

What a difference to sound quality, not tinny and sound much much better. Possibly too loud for the farm sound effect and I cannot find a similar suitable 8 ohm speaker, that is one with holes for mounting. with this in mind and looking ahead to when I have a number of background sounds running at the same time I can see that I may need to balance their individual volume levels and I'm wondering how I can do that. I have some DC to DC buck converters that have a potentiometer to adjust the voltage, If I use this to adjust their output voltage to between 5v and say 3.5v will the MP3 player still work at the lower voltage and if it does will it reduce the gain through the amplifier and therefore the sound volume? If this works it will be by far the easiest solution. I know that I can adjust the amplitude of the sound file itself but that will mean a lot of faffing about as I cannot do it on the layout.

[Steve M]

I can’t help thinking that you are trying to make this more difficult than it needs to be.
In the other thread there is a link to mp3 boards complete with various controls including volume, track selection, repeat etc. They require a tf card (micro so) with a suitable soundfile and a power supply.
Speakers with the right ratings are easily available on eBay - look for TV spare parts.
All you need then is an on/off switch and they will happily play all day for less than a fiver each.
I use two for farm and harbour sounds + the Hornby TTS van.

[Nokonium]

Steve M, sorry but I’m from a quality management background, inbuilt into my basic thought processes is risk assessment, I therefore intuitively look at what could go wrong.

I have moved to the suggested MP3 module because, on assessment, it works better than the other one I tried. However when I tried following other links to other products eBay suggest that I had missed out.

I have looked extensively at speakers but failed to find suitable speakers, I.e. ones that have screw holes so that I can attach them to the underside of my baseboard, of a higher impedance. I can find similar speakers with 8 ohm impedance but cannot see how I can easily attach them to my baseboard.

My general scheme is to have east and west control panels for both lighting and sound. The power module (one for each sound effect because of the current required) and the MP3 player easily accessible (for replacement of the module or replacement of the SD card), then run connections from the MP3 player to the speaker, which is attached to the underside of the baseboard. I already have Control Panels where I can select what I want, with led indication of selection. I have three non track control panels, one for points and signals (Cobalt Alpha and DCC) and two DC panels, one controlling lighting and sound to the east and the other controlling lighting and sound to the west.

[Nokonium]

I have removed the non adjustable power step down module and replaced it with one of the adjustable ones, unfortunately adjusting the voltage doesn't have the desired effect so it is down to messing around with the recording volume on Audigy.

I have to add how much I like these adjustable voltage power step down modules - LM2596 DC to DC Buck Converter 3.0-40V to 1.5-35V Power Supply Step Down Module. A pack of 6 cost me £8.75 delivered from Amazon.

https://smile.amazon.co.uk/gp/product/B ... UTF8&psc=1

[Nokonium]

I think that I understand why the first board didn't work, it needed to work with an Arduino Uno

https://www.youtube.com/watch?v=fflIHcHf_Kg

The one in the video with switches on the breadboard can be used to select different tracks, makes me think that it could be used for custom station announcements.

[teedoubleudee]

Regarding station announcements, I made a module using a Hex switch and Picaxe mpu. You just turn the knob to desired sound and press the yellow button. The Picaxe deciphers the hex code and selects the appropriate track from the TF card. I know I could probably done it without the mpu but I used as a software learning exercise. The 4 little leds on the board are only for show and give the hexadecimal code the switch is set to.

[nigelwright7557]

I did a station announcement system many years ago.
I cant remember now which IC I used.
It had a record mode and playback mode.
I also play guitar so used my echo effects to enhance the voice.
For a little box it was pretty loud and went down well at shows.

[Tricky Dicky]

I have looked extensively at speakers but failed to find suitable speakers, I.e. ones that have screw holes so that I can attach them to the underside of my baseboard, of a higher impedance. I can find similar speakers with 8 ohm impedance but cannot see how I can easily attach them to my baseboard.

Small speakers without fixing holes can be held on their sound boards by driving in round headed screws against the edge of the speaker. Because the round head screw has a flat underside on the head the overlap grips the rim of the speaker. If that does not work a small washer usually does the trick.

Richard