groovy- Stalling over turn outs was my biggest concern with these short wheel based locomotives so I am glad to hear you have not had any problems.  You are certainly well rounded on these little Bachmann "critters". I'm going to take your suggestion and mount the speaker underneath the cab roof and I do appreciate you taking the time to share your experiences with me.

groovy- Cool...and thanks for the offer.  I've installed about 5-6 Select Micro's but all in larger loco's and I know what you mean about the loudness.  The default volume level is high enough to rattle the rafters..  With the advent of these  next generation membrane speakers I started putting two speakers wired in parallel in each loco and have beenvery pleased the the results.  Clear, crisp and robust.  I got onto a Company called Knowles that has been making these membrane speakers for cell phones, tablets ect.  The one I have been using is a 13mm x 18mm.  Now they just introduced a membrane speaker using silicone for the membrane that is supposed to outdo all the others.  It only comes in an 11mm x15mm configuration.  I think I'll order one of those and a TDS Super-Sonic and see which one sounds the best to me.  I've never had a loco as small as this 45 tonner but I am intrigued with it.  The other concern I have is stalling. on turn outs.  Have you experienced any problems with this?  Thanks for indulging me.

groovy- So you glued the SuperSonic and enclosure to the roof of the cab firing down, right?  Looks like the body shell is one piece so did you open any of the side windows to let the sound out or does it sound ok as is?

I'm seeing mixed reviews on the actual hole size for the speaker.  Some report the diameter is 10mm while others are saying 13mm.  I guess the only way to find out is when I get the locomotive.  Either way I'm beginning to abandon the idea of using the hole in the air tanks and leave the weight in there and go with a membrane speaker like a Zimo or SuperSonic.  By the way groovy, where did you end up mounting your SuperSonic?

Actually, Lenz makes a Keep Alive that will fit in both the 44 and 45 tonners, at least when using the ESU micro decoder.  It's called a Lenz Power-1 USP Energy Module and is sold by Tony's Train Exchange.  Downside...it's $65 plus shipping.  Yikes!

Thanks for the help and advise guys. 

Thank you for the idea.

Thanks for the article Hunt.  He has a YouTube vid that somewhat mirrors his article and refers to a 4 ohm, 10mm speaker but doesn't mention the brand.  LokSound offers 4 ohm speakers but they don't list a 10 mm.  May try and contact him directly.

Again, thanks for the link.

Hello guys (and gals),

I am brand new to this forum so please excuse my ignorance if this topic has been rehashed a thousand times before.
I have a 45 tonner on the way and would like to add sound.  My concern is with speaker selection and from what I've been able to gather the factory provides a 10 mm hole in the gas tank for this purpose.  I am familiar with membrane sub mini speakers having installed quite a few but can not find any of the correct dimensions to fit in this locomotive.

So I'm curious if there are any members out there that have installed sound in one of these critters and if so what speaker configuration you used.  As a sidebar, I will be incorporating a LokSound Select micro for the sound decoder.

Much obliged for any thoughts or suggestions.

Side Rod