Exhaust Speaker Grille?


Ranger_10x

New Member
I am adding DCC sound to a HO FT-a loco but there's no place to put the speaker to allow the sound to escape to the outside. Wondering if there is some type of (open) wire mesh exhaust grill that I could put on top that would fit in (appearance-wise). Wouldn't have to be pretty or prototypical. Other idea is to put the speaker in the non-powered b unit (plenty of room there) but not sure how to wire the two together. Suggestions?
 
you could try using the wire ribbons from a art store like Michael's. They are made of wire and have a fine mesh. Just an idea.

Dave
 
I am adding DCC sound to a HO FT-a loco but there's no place to put the speaker to allow the sound to escape to the outside. Wondering if there is some type of (open) wire mesh exhaust grill that I could put on top that would fit in (appearance-wise). Wouldn't have to be pretty or prototypical. Other idea is to put the speaker in the non-powered b unit (plenty of room there) but not sure how to wire the two together. Suggestions?
I have mine in the B unit, but most people just "fire" the speakers down through the openings for the trucks.
StewartSound.JPG
 
you could try using the wire ribbons from a art store like Michael's. They are made of wire and have a fine mesh. Just an idea.

Dave

I was thinking something like that but would want some kind of micro-connector so I could uncouple the A from the B. Is that wire super flexible? I have an MTH K4 that uses an electrical connection built into the drawbar to the tender - that would be ideal.
 
I have mine in the B unit, but most people just "fire" the speakers down through the openings for the trucks.
StewartSound.JPG
So Iron Horse - I take from your photo that your B is powered? And also assume it then has its own decoder so you can run the speaker off of it? If I'm correct about that then do you consist the A & B together by using the same address? As my brain is catching up my wallet is starting to groan at the thought of upgrading to a powered B unit. Thanks a lot! Lol
 
So Iron Horse - I take from your photo that your B is powered?
No, that is all my super tuned base ported speaker.

And also assume it then has its own decoder so you can run the speaker off of it? If I'm correct about that then do you consist the A & B together by using the same address?
Yes, that white blob on the front of the unit is the "plastic" sleeve around the sound decoder.

Track power is transferred from unit to unit through the micro plugs at either end of the unit. One could just as easily use 4 pin plugs for either the speakers or motor between units.

I programmed all the decoders to the same channel but that is because the units are always hooked together. It would have been just as easy to have them on different channels and actually "consist" them in the DCC unit to all run together.
 
Big Bad Baffle

No, that is all my super tuned base ported speaker.

Yes, that white blob on the front of the unit is the "plastic" sleeve around the sound decoder.

Track power is transferred from unit to unit through the micro plugs at either end of the unit. One could just as easily use 4 pin plugs for either the speakers or motor between units.

I programmed all the decoders to the same channel but that is because the units are always hooked together. It would have been just as easy to have them on different channels and actually "consist" them in the DCC unit to all run together.

Iron Horse, you must get great sound from that arrangement. I guess the 'B' for your b-unit stands for Boom Box!
 
Glad you posted your "B" unit, I'm considering doing something similar with an Alco PB dummy, but run the speaker/s? within from one or other of the 2 sound decoder powered units either side of it.
 
Glad you posted your "B" unit, I'm considering doing something similar with an Alco PB dummy, but run the speaker/s? within from one or other of the 2 sound decoder powered units either side of it.
Yes, an ALCO PB unit makes a really good speaker enclosure. Plenty of room for baffles and air channels. One can also use the rooftop round vent for either a port or for an upward firing speaker. What you are proposing is what Precision Craft did with their PAs, and what Broadway Limited does for their EB units. Sound decoder in A unit sends the audio signal to the speaker in the B unit.

Below is another dummy unit I've done which is an Athearn blue box. I cut out the bottom of the fuel tank so that the speaker could fire downward with minimal obstructions and still keep the magnet weight closer to the center of the unit. The inside of the body (speaker enclosure) needs to be beefed up a bit more. It vibrates sometimes. Vibration = lost sound quality(fidelity) & volume.
bigspeaker.jpg
 
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I am adding DCC sound to a HO FT-a loco but there's no place to put the speaker to allow the sound to escape to the outside. Wondering if there is some type of (open) wire mesh exhaust grill that I could put on top that would fit in (appearance-wise). Wouldn't have to be pretty or prototypical.
Oh, missed a question in there. Unfortunately the FT unit has only 4 vents on the roof, none of them mesh type. The dynamic brakes were mounted on the roof not through the roof so they have no grills. I think it would be a major effort trying to put sound up through (around) them. That is one I have never attempted.
 
You really don't want the sound to "escape" through any openings. If anything, you want to seal up any and all openings. A sealed shell acts like a second order speaker enclosure. The sound resonates within the shell and comes out the bottom. The entire engine becomes a sound chamber.

With any openings in the shell, it becomes clear that is where the sound is coming from. If the speaker is right under the exhaust and the horn is right in the same area, you could get away with it, but the sound reproduction is still sharply directional and weaker than if it were using the inside of the shell as an enclosure as well. That fills the entire engine with sound. As the sound eminates from below the engine, it's hard to pinpoint exactly where the speaker is located.

Don't take MY word for it, compare both ways yourself. I've done hundreds of sound installs and my experimentations clearly told me to seal up the shells.

Mark.
 
Mark, your reply is interesting, what are your thoughts on the use of more than one speaker, it it's possible to mount, say a larger bass reflex near the motor/exhaust position and a smaller, higher frequency one towards where the horn and bell are? Can they be tuned in any way and if so, is there a better decoder to use in this circumstance?
 
Mark, your reply is interesting, what are your thoughts on the use of more than one speaker, it it's possible to mount, say a larger bass reflex near the motor/exhaust position and a smaller, higher frequency one towards where the horn and bell are? Can they be tuned in any way and if so, is there a better decoder to use in this circumstance?

The enclosure itself has a lot to do with how it sounds as well. A plastic box to mount a speaker in - while very simple - is far from ideal. Try mounting your home stereo speakers in a plastic tote box and see how they sound ! That's when I moved to making my speaker enclosures from thin 3-ply wood, the type model ship builders used. This vastly improved the richness of the sound from the same speaker. That was my go-to set-up until these cell phone speakers became common.

I started the experiment process all over again with these little speakers, trying all different kinds. I've finally settled on the HTC ONE M8 cell phone speakers. These provide amazing sound for their size. The MTC ad for this cell phone touts it as Boomsound ....

http://www.htc.com/us/smartphones/htc-one-m8/boomsound/

These speakers can be found all over ebay and come like this ....

speaker.jpg

The dimensions are 45mm X 11mm X 6mm at the extremes. They are small enough to easily fit in any engine shell. For some really impressive sound, mount one at each end of your engine. I've yet to experiment with them to the extent of digging the speaker out of the enclosure and mounting it in a small wood enclosure, but I'm sure the net result should be even better.

Mark.
 
I have been trying to find some light plywood of the sort you mentioned on our ebay without luck, can import it at exorbitant prices and even more exorbitant shipping, so will try the couple of hobby shops we have here, or a craft shop. Wouldn't want anything much thicker than 1/16"?. I got some claimed iPhone4s speakers, but they are really tiny, 3/8 x 9/32 x 5/32 and no way of telling which contact is + or -. Can get the ones you showed and I came across a review of one installed in one of the new Athearn RTR SD40 w/sound locos, which said it was much better than the factory fitted (no surprise 'cause I have 2). Found out that the Tsunami decoder in them is similar to the "Sound Value", Bachmann are using, which is based on the old Tsunami.

Did see some of those HTC ONE M8 with enclosures on a local ebay site and the same elsewhere without their enclosure.

If there is room, would you suggest increasing the capacity of the enclosure to fit the space, or is there an optimum size that works best. I was even thinking of making an enclosure with one end open and making an end bit that would fit within the walls of the box, attach it to a stick and slide it back and forth inside to find how capacity affects the sound quality.
 
I use the 1/32" plywood for my speaker enclosures. I get mine from a local guy who makes laser cut buildings, but Micro Mark carries it ....

http://www.micromark.com/SearchResult.aspx?deptIdFilter=0&searchPhrase=plywood

Unless you are using multiple speakers, the polarity doesn't matter. If you are using two speakers (or more) just designate the terminals yourself and wire them appropriately in series or parallel. Be careful when purchasing the HTC ONE M8 speakers. The phone has two speakers in it - the ringer and the loudspeaker. The ringer is the speaker by itself, the loudspeaker is the one in the enclosure. Not sure if the rating for both speakers are the same or not .... yet. They "look" the same, but I'm not sure if they are.

Cell phone speakers require a very small enclosure - usually around 1 to 1.5 cubic centimeters - that diaphram doesn't move as much as a typical cone type speaker. A larger enclosure will end up diminishing the sound. It is also VERY important that the enclosure be sealed air tight to the speaker. Even the slightest leak will greatly affect the sound quality.

Mark.
 
I followed the advise in this video when I mounted a speak in my Hudson. I get AMAZING sound out of it now with just an MRC speaker.
https://www.youtube.com/watch?v=j4kgLeDltxg

As for the grills, I would interested in finding them as well. I would like to put sound in my Bachmann GP-40. I would disagree slightly in that there should be an opening for the sound to come out of the shell, but you would want to seal the rest of the speaker up so the sound waves have further to travel (watch the video and that statement will make more sense).

There are as many theories on sound as there are model railroaders, though, I'm sure.
 
I am adding DCC sound to a HO FT-a loco but there's no place to put the speaker to allow the sound to escape to the outside. Wondering if there is some type of (open) wire mesh exhaust grill that I could put on top that would fit in (appearance-wise). Wouldn't have to be pretty or prototypical. Other idea is to put the speaker in the non-powered b unit (plenty of room there) but not sure how to wire the two together. Suggestions?

By the way, back to original question, check out Cannon: http://shop.cannonandco.net/ or Plano: http://www.planomodelproducts.com/dieseld_scq.html
 
There are as many theories on sound as there are model railroaders, though, I'm sure.

Seems that way. Something that's puzzled me about Athearn's Genesis SD70ACe's and ES44AC models, and now the RTR SD40's. The speakers in both of the ACe and ES are mounted vertically in a separate weight behind the motor and fire into a recess in the weight, the back of the speaker being exposed and facing the side of the long hood. Earlier versions apparently had a port in the bottom of the weight's enclosure, presumably to allow sound out. Newer ones have that sealed off, and I saw an article or vid where the author advised doing the same to the early ones. With the SD40's, they have made a weight that extends out over the rear gear tower and mounted the speaker in a recessed enclosure in that weight, from the top, firing down into that enclosure. In one article I read about using these Cell speakers it said they must only fire into an enclosure, not out.

Here is a good sound comparison between the stock Athearn SD40 speaker (not the same as the ones fitted to my 2) and an iPhone4 speaker
https://www.youtube.com/watch?v=H9jHqkbllzg
 
Been looking for those HTC speakers on ebay.com.au (our one), but there are loads of "generic" ones at all sorts of prices that you have to wonder how good they will be.
 



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