Model Railroading > Scale Trains SD40T-2 and SD40-2 Iphone Speaker Upgrade

Since I was asked to make a seperate thread on this, I took some better photos to show the process. 

1 - This is where the speaker will sit.  The speaker is from an Iphone 4S, and is sometimes called the "Buzzer" or "Loudspeaker".   They can be had rather cheaply online.   

2 - The speaker needs to be trimmed down to approximatly 1 3/8" long.  This will not effect the sound in any way.   You can trim these down to the solder tabs with no real change in sound.   This is not a precise science either.  

3 -  This is the finished speaker.  You MUST cap the end of them, and reseal it.  This is easily done with some .020" styrene and super glue, making sure to get a good bead all the way around.  



Edited 1 time(s). Last edit at 04/01/19 15:43 by sixaxlecentury.

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4 - Pop off the decoder, and look for the speaker wires on the board.  They are marked S+ and S-, seen here circled.   Carefully unsolder these wires.  

5 - Take off the little plastic cap in the back and trace out those wires.  There is two black, and two red.   Cut them right at the weight.  Be very careful NOT to cut the power pickups, as they are also black and red.    Take one of each wire, and reattach them to the board. 

You CAN skip this if you are not comfortable soldering to the board.   You can simply cut  the wires flush as described, and just reroute them to the front.   I choose to chop them to keep it a little cleaner.   

6 -  Run two wires up to the new speaker, solder the leads,  make SURE to shrink wrap each one as they are very close together.   

Done.  I literally just did 4 of these in 45 minutes, start to finish.   There is no reason to even bother pulling out the old speakers unless you really want to.    This is the exact same procedure with the SD40-2, but one thing to note, if they have a beacon or strobe light, the speaker needs to be cut a touch shorter, as the shell uses two spring loaded prongs that touch contacts on the lighting board, which must be kept clear.  

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How much of an improvement in sound do you get?

It is literally night and day. The iPhone has more bass, its clearer, and the sound is now right at the exhaust stack, it buried in the weights by the trucks.

OK. Stupid question #1. Where did you get the iPhone speaker?

gandydancer4 Wrote:
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> OK. Stupid question #1. Where did you get the
> iPhone speaker?

They are bountiful on ebay.    Bill over at PDC also sells them in 4 packs.  http://pdc.ca/rr/catalog/product/harnesses-keep-alives-and-other-accessories/63

I'd be interested to hear a before and after to tell the difference. This kind of thing is always surprising to me because I'd think these manufactures are putting the best speaker than can in their products already. I just find it hard to believe a 1/2 an old phone speaker is an upgrade. 

Rapido uses these exact Iphone speakers.  

The issue with the stock ones is they crackle, which to me tells me its a cheap speaker, and no amount of volume tuning helps.  The other issue is they are in an enclosure that is not sealed tight enough.  

Thanks for posting this write up. Been wanting to try this speakers for awhile now anyway.

My speakers arrived today. I didnt realize how thin they actually are. Have you toyed with the idea of running two of them?  I just might try that. Also noticed that the speaker chamber had some sort of poly fill to increase bass response. These speakers are no joke.