Hi All,
I'm trying to figure out best placement for a speaker on an LGB Porter. I have seen a few installations where the speaker is placed in the top of the smoke stack, but this won't work for my Porter because it has a smoke unit.
Bachmann places speakers in the cab for its On30 porters with factory equipped sound and I think this may be my only option. Luckily there is quite a bit of room in the LGB cab for a speaker enclosure, which could be disguised as a small pile of cord wood.
Speaker baffles work better than enclosures, but I'm having trouble thinking of a way to accomplish this on a tenderless locomotive. Has anyone seen this accomplished?
A few options. I put a 1" speaker in the boiler itself, up at the smokebox. I don't know how much room the smoke unit takes. It's a 1" speaker, though, and you'll notice it sounding a little "thin" compared to the larger speakers in your other locos.
In my Porter, I built a coal bunker on the fireman's side to hide the battery. If you're using track power, you can use that space to build a speaker enclosure for a 1.5 - 2" speaker. You've got about 7/8" to play with between the boiler and inside of the cab wall. You may find an oval speaker which would fit in that space.
Later,
K
I've not done this myself, but have seen three possible solutions.
1. Thin wall balsa wood box with holes drilled through the floor of the cab for sound to pass.
2. Air gap on back side of the box.
3. By far the best sound and probably the hardest to make. Build the skelatal frame of the box. Find fabric with a wood grain. Slice into strips. Sew the strips together to form the planking of the box. Glue the fabric 'planks' to the box frame and cover the corners with balsa strips and a diagonal brace.
Tom Trigg
Thanks for the suggestions. I'll be considering all of them closely when I finally get the Porter in front of me and I can take measurements.
I've thought of another option that may reproduce the baffle effect I'm hoping to achieve. There is quite a bit of surface area on the cab roof. I'm thinking of attaching 2-4 of the Wow speakers to the underside of the cab roof and then making a false ceiling to hide them. The ceiling would be made with styrene strips simulating wood paneling, with enough gaps between the strips to allow positive pressure waves to pass through.
I'm then going to see if I can make some kind of holes at the front of the cab, possible disguised with trim, to allow the negative pressure to equalize so the false ceiling acts as a proper baffle. I don't know if this will provide the 8" of travel that is recommended for maximizing a speaker's effects, but I'm hoping it will be close.
I silconed my speaker the magnet part of the speaker directly to the ceiling of the roof. Remember 99% of people viewing ii will be looking down, not up and you can get a fair side speaker up there. The sound bounces all around that cab on the way out. Have only had 1 speaker come loose out of 7 and just cleaned the silicone off and redid. Bill
Get the Garden Railways newsletter delivered to your inbox twice a month