SoundTraxx Tsunami sound decoder fit in N-scale tenders?

The 1amp version might fit in an N-scale tender. The dimentions on the decoder are: 1.68" by 0.68" by 0.25" So the question really is, what tender are we talking about (since tenders come in different shapes and sizes). Paul

Here is a LifeLike 2-8-8-2 with a sound decoder & speaker in tender and decoder chip in engine. I wonder how much larger the Tsunami decoder is? - not sure what the size of this one is. Engine -http://www.tonystrains.com/gallery/n2882-wi-sound-a.htm Tender - http://www.tonystrains.com/gallery/n2882-wi-sound-b.htm

A little late to the party, but I found this thread yesterday. I've just completed a Tsunami install in a Key Brass (Samhongsa) GS-4. The Tsunami package fits into the tender with minimal side clearance. There is enough room on each end to allow rear tender lighting and some slack wire, but the GS-4's tender is fairly large and boxy. I used a .63" speaker from TTX. It's extemely low-profile, and delivers good sound quality. No size problems stacking the decoder atop the speaker. The Tsunami is unwieldy enough that you'll need a fairly good space inside the tender. It also runs fairly warm, the back side of the decoder has a heat speader! It won't melt anything, but it might raise a few eyebrows if you're anywhere near the current limit. It will work for most large locomotives, but you might need to remove pre-installed "DCC-ready" boards (eg. Con Cor) to make room, and anything with a Vanderbilt tender is right out. I'm still programming the innumerable CVs to get it just right, but all in all, this is a phenomenally good decoder. The sound quality is astounding, even in such a small space. For reference, I've previously done quite a few installs (a dozen locomotives or so, and a number of passenger cars, all Digitrax, none merely "drop-in"). Gallery: http://www.nscale.net/mod-photoshare-showimages-fid-507.html

I can comment on the modern (90's CC/China) version, which I owned a while ago. I have little/no knowledge of the older (70's Kato) version. The length of the CC J3a tender can accomodate the TSU-1000. Double-check the inside clearance, though, as I can't say for sure that the width is sufficient. It'll be close. However, there are two immediate problems that will require solutions to install a Tsunami (or any sound decoder) in this tender:

The tender's cast weight takes up a large portion of the inside space, and will probably not allow a thick decoder to stack on top of it. You'll need to find an alternate weight (flattened lead?). and a way to mount it, because: The tender weight covers two copper strips for the tender power pickups, which traverse the entire length of the tender. This means that either the speaker must be installed facing upward through the coal (with very small holes drilled there), or you must re-engineer the pickup mechanism to allow speaker to be mounted downward in the center of the tender. IIRC, the tender also has a water scoop between the trucks, so you might have to be creative in providing speaker holes if you opt for center mounting.

The Tsunami is heavier than most decoders, but it probably needs supplemental weight to insure smooth operation. I didn't have to tackle this problem since the tender shell on my install was brass. The tender only had two small extra brass plates for added weight, and the Tsunami was about the same. The toolbox weight idea is a good one. In this case, the speaker would have to be mounted facing up into the coal. Link to Tony's speakers: http://www.tonystrains.com/products/tteexclusive_spkr.htm Again, I used the .63" round speaker. (The mini-oval might also work, depending on space, but didn't notice it at the time.)

Regarding the enclosure question: When a speaker creates sound, it does so by creating pressure waves in the air. If the back of the speaker is exposed to the same body of air as the front, the air quickly move from one side of the speaker to the other, which equalizes the pressure, and the sound disippates. HowStuffWorks link: http://electronics.howstuffworks.com/speaker9.htm For diesel installations, the body of the diesel doesn't provide a resonance cavity for the sound, so adding an enclosure is almost requried to get good volume/quality of sound. Tenders are naturally boxy and (relatively) empty, so they already possess the acoustic qualities that an enclosure provides. To get the best response from a tender installation, the speaker should be sealed to the tender body around the edges, so that air will only move through the speaker holes/grill. No other enclosure is necessary. See my photo (from the gallery) for a detailed picture of my speaker install: http://www.nscale.net/index.php?module=photoshare&func=viewimage&iid=3846&thumbnail=0&viewkey= I made a gasket to seal the speaker using 3M double-stick tape. It's made of foam rubber, so it seals very well. I only used one side of the tape, and the speaker is held in place by friction.