Here are a few photos for installing baffles in HO PCM & BLI F3 & F7. I use an old paper tube holder slit lengthwise and reduced in diameter to 28mm using a 27.45mm glass bottle.
I used 5 minute epoxy to seal tube overlap and the coated the outside of the tube with a thin coating of 5 minute epoxy after tube tube overlap was dry.
I used a piece of 040" styrene for the cover. Sealed the cover in place with a thin coating of bath caulk.
Bath caulk to attach the baffle to the loco.
I will do this with the B unit and also my PCM F3 A/B units which are identical inside.
The idea came from a fellow in South Africa who did this with his PCM diesel.
A nice one evening project while watching the Red Sox lose again.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Now the real question, did it actually improve the sound? I'd think the paper would be too flexible to actually 'contain' the sound pressure waves, plus if the speaker on those is sealed to the bottom of the frame, there already is a much larger baffle formed by the entire shell.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
My original post I said, coated the tube with 5 minute epoxy. This makes a very rigid tube along with the 0.040" styrene cover plate.
Without an anechoic chamber and proper test equipment, it would be difficult to know how much improvement. Remember, DCC sound is a very subjective.
I will try a side by side comparison with shells in place as my PCM has a LokSound decoder versus the BLI has the Tsunami. Both are 28mm speakers but one is 100 ohm, the other 8 ohm.
Not sure my 69 year old ears could tell the difference.
The idea came from John Burkhardt of South Africa who has done a lot of DCC installs.
Do a Google search for John Burkhardt DCC installs.