Adding Sound Decoder to DCC Equipped Loco

[TrinityJayOne]

Apologies for the newb questions, I know this likely gets asked all the time but I'm really struggling to find answers. I'm returning to the hobby after nearly 20yrs away from it, picked up my first N-gauge loco the other day and want to get some sound happening. It is this one (http://www.internettrains.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=IT&Product_Code=ATL-51971&Category_Code=NSCLOCDSLATL4WD&Featured=). I looked at this replacement decoder (http://www.digitrax.com/prd_mobdec_sdn144a0.php), as it apparently fits an 8-40C and I can't imagine the addition of a wide cab making that any harder. My concern is that- A. the engine runs reeeeeeeeeeeeeally well with the factory-installed Atlas decoder and I don't want to mess this up, B. I don't want to lose the ditch light functionality I currently have. This LokSound (http://www.internettrains.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=IT&Product_Code=ESU-72846&Category_Code=PDSLCDESUMDD&Featured=) decoder looks even better, but it seems like it'd require more farting about to get it installed. Am I correct in saying either unit is going to require re-soldering of all the lights to the new board? (I haven't soldered anything in ages, but I was alright at it as a kid so I'm sure I could manage it now)

The second option is to showhorn a sound-only decoder into the cab, but the speaker would need to be small and I don't know how complex this would be and/or if it would make activating things like horns a pain (I assume you'd need to switch to the 2nd address for that?). I'm also aware of putting the sound into a trailing car, but I think the sound not coming from the train itself would get to me because I am slightly OCD about these things. :D

Thanks in advance for help, or links to a thread where this has already all been answered. :)

[gc53dfgc]

Well a drop in decoder will replace the current one. The LokSound decoder is the correct sound scheme while the tsunami is a GP38 or EMD645 prime mover while you need the GE FDL-16 decoder from them. All decoders you install to replace an old one will need to be soldered. The tsnuami will keep the current running characteristics and ditch light functionality.

http://www.modeltrainforum.com/showthread.php?t=5603
These are installs I did for HO but the principle stays the same when transfered to N scale.

[NIMT]

While the principals of decoder installs work for both HO and N they much harder with N!
The space involved to do the rework is so much more limited!
Most proper N sound installs require that you cut open the body and add aftermarket fans or holes to let sound out!
While you say that someone thinks that a drop-in decoder will work for another style of engine, I find that to rarely be the case.
Soldering a decoder into an N is not the problem it's cutting the frame to fit the decoder and speaker that can be the problem.
You can buy all the components and see if you can do it, but keep in mind most suppliers will not allow returns on opened or altered equipment.
N scale sound can be done, They also do Z too!
Just take your time and have a really good set of magnifying goggles to help you see, Don't force any parts into place, Test often, before installing lights, and replacing the body.
Installing Sound into an N scale engine will effect it's performance! You are using energy to create sound, Matching loco to run together between sound and non sound is extremely difficult.:cool:

[TrinityJayOne]

Installing Sound into an N scale engine will effect it's performance! You are using energy to create sound, Matching loco to run together between sound and non sound is extremely difficult.:cool:
Oh really? Didn't think of that. :eek: Reduced speed doesn't overly bother me as currently the model looks prototypical at much less than full throttle, but having to match power curves with non-sound would be a pain, you're right. At least it would only be an issue for MU I guess. Could always put sound in multiple locos! :laugh: