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Sound & Sugar-Cube Speakers Locos and rolling stock
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Prolific poster 8,773 posts railandsail Prolific poster 8,773 posts
railandsail

Sound and Sugar-cube Speakers

This was just recently posted on a Soundtraxx discussion I had started about the incompatibilities that could arise when running MTH locos with other DCC equipped locos. I found this 'sounds portion' very interesting,...

Quote:

QUESTION: What size sugar cube speaker to install in smokebox?

REPLY: My pragmatic response to this query would be “the largest that can be fitted”.

I have now placed a lot of these small speakers (with enclosures) in the smoke boxes of my varied brass locomotives, and each install is different. I do favor the 13x, and 11x sugar cubes if they will fit, but have also gone down to 9x and 8x (both in pairs). They all seem to work well, and sound great- enough different from each other to make it interesting. I use the 3D enclosures from Streamlined Backshop, each of which has enough meat so that one can quite effectively sand, file, or even -with care- a saw to thin and shape the sides to fit.

I have detected no auditory advantage (to my ears, anyway) with dual speakers, except when desired volume with quality sound cannot be obtained in any other way (such as with the small 8x speakers).

Generally, I have firmly moved to never, ever again put speakers in tenders, and I already have removed tender speakers in some in favor of smokebox sugar cubes, or sugar cubes in boiler, fire box, or form fitted under cab roof. What tremendous improvements! The SP cab forwards are an exception, where the the smokebox is separated from the tender by only an apron. Even so, I would bet that two fine sugar cubes alone in the smokebox would do the trick (I have a brass Winton 2-6-6-6 Allegheny with two 13x sugar cubes in the fire box that simply sounds as this gigantic locomotive should sound..

A truly successful recent install was in a KTM LS&MS 4-6-0 (1964). This graceful lank locomotive simply did not have enough room for decoder (Tsu 2 Micro) and speaker of adequate size- without compromising fundamental operating requirements. I installed the decoder in the tender, and a 11x sugar cube facing down in the boiler space above the driveline. The results are spectacular (i.e. spectacular). Tender and locomotive are connected with TCS micro connectors (a six and a two), and wires effectively disguised with a generous application by a black Sharpie pen.

Denny S. Anspach MD
Sacramento CA

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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railandsail Prolific poster 8,773 posts
railandsail

No Speakers in Tenders ,...only Sugar-Cubes !!

Generally, I have firmly moved to never, ever again put speakers in tenders, and I already have removed tender speakers in some in favor of smokebox sugar cubes, or sugar cubes in boiler, fire box, or form fitted under cab roof. What tremendous improvements!
 

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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railandsail Prolific poster 8,773 posts
railandsail

This was a recent reply to

This was a recent reply to that idea, and the video that was referenced is one I had viewed a number of times some number of years ago when I was really following the subject

Quote:

The first loco I put sound in, I just used a regular speaker box inside the shell. Sounds ok... just ok. Then I watched this video and my next two installs were 1000 times better:

MRH DCC columnist Bruce Petrarca
https://www.youtube.com/watch?time_continue=4&v=j4kgLeDltxg

 

 

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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railandsail Prolific poster 8,773 posts
railandsail

Put the sounds in the place they are supposed to be

 

Quote:
I notice those in the club who run steam, even with HO, the sound seems unrealistic when the speaker is in the tender, especially with the longer locos. One member added a small, additional speaker in the smoke box that enhanced the chuff and sharper steam sounds markedly. Put the sounds in the place they are supposed to be.
tootnkumin

 

Back a number of years ago I was doing a lot of reading (and some posting) of this sound subject (and yes KB02 I remember that video well). At that time there was very little (almost none) of the cell phone speakers being utilized. We were looking for spaces where conventional speakers could be placed, and in the loco shell itself,... that offered almost no possibilities.....so the tender installation became the place.

Then it became a study of how to envelop those speakers to the best effect,...very much akin to the old tech of stereo h-fi home speakers. But the sound was still emanating from the tender, not the loco itself. I recall seeing one experiment done by a friend of mine where he placed the speakers in the tender, BUT had them facing out a relief in the front of the tender, blasting into the fireman's cabin on the loco. It was a very surprising the effect !!

Meanwhile what really surprises me about the cell phone speaker success is that I was always a believer that sound was better produced by being able to move 'quantities' of air, thus larger speakers. Doesn't seem to be necessarily so with this sugar-cube speaker technology.

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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railandsail Prolific poster 8,773 posts
railandsail

Sound from Front of Tender?

I'm investigating this whole subject of optimum sound installations in HO model trains. I ran across this PDF document with good explanations and nice illustrations. Thought this forum might find it interesting.


http://www.qsisolutions.com/pdf/loco...ics_design.pdf

Quote:
As I re-read this PDF document several times I became aware of a possible speaker installation that was not covered in this document....excerpt:

"Separate back wave from front wave: It is important for sound quality that the inside cab area be sealed as much as possible to prevent the back wave from escaping through grills, vents, fans or other openings in the diesel or electric locomotive cab or through the openings in the chassis where the motors connect to the trucks. If there is any leakage of the back-wave to the outside, it will mix with the speaker front-wave and cause destructive inference in some base tones and perhaps constructive interference for some of the higher frequency tones. The respective path lengths for the front-wave and the escaping back-wave and the position of the listener will determine which frequency components are degraded or changed. Usually, since the acoustic chamber and path lengths are short, any back wave escaping from the locomotive causes degradation of the sound. If the back wave is allowed to escape close to the front-wave, the degradation is more severe. As the scale of the model decreases, this becomes more of a problem since the distances between front and back waves become smaller.

Vent the front-wave sound under the locomotive: Propagating sound upward into the open air seems to produce lower quality sound unless you are directly over the speaker. The sound has no opportunity to reflect against different parts of the layout such as buildings, mountains, etc. that add both volume and presence. Our experience is that the best design choice is to propagate the sound under the locomotive. The next best choice is out the sides of the locomotive through vents and grills. If sound is vented under the locomotive, always be aware of the affect of trucks and other obstacles and other factors that can either improve or degrade sound quality. Do not vent sound straight down too close to the track where it can be reflected back and decrease volume and sound quality. Venting the sound directly under the fuel tank usually does not produce good sound in smaller gauges (HO and N) since there is little space between the bottom of the fuel tank where the sound is vented, and the top of the track. Sound usually reflects back from the track resulting in poor volume and presence. Venting through the gear tower and chassis over the open truck areas seems to produce the best sound."

What I find interesting here is no mention of venting the 'front-wave' from the front of the tender, verses out the bottom, or out the coal load?? Why does this interest me? I have at least 4 locos with vandy tenders (C&O) that I wish to install sound into. He covers vandy tenders to some considerable degree, but does not mention this possibility.

I happen to have a friend who has a relatively cheap little IHC steamer that has its sound vented out the front bulkhead of the tender right into the cab area of the loco....the sound is GREAT. On the other hand I have a 2-8-8-2 with the sound vented out the coal load that I consider substandard. So I am giving real serious consideration to experimenting with one of my Spectrum C&O Heavy Mountains with their vandy tenders and venting the sound forward out of the tender.

Has anyone else seen such an installation? Does anyone have a photo and/or illustration of the 'factory sound' installation in these Spectrum models??

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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Greg Williams GregW66 Prolific poster 1,305 posts
Greg Williams GregW66

In the middle of it all

I'm in the middle of a steam sound install and bought all materials before I heard the Sugar Cubes. Now I am regretting the rectangular speaker I've chosen, and heavily modified the tender for. I'm going to have to rethink it.
Greg Williams
Superintendent - Eastern Canada Division - NMRA
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railandsail Prolific poster 8,773 posts
railandsail

Inventory of Speakers

I've got a number of regular speakers as well to eventually install in some of my locos when i get to that stage. likely I will use some of them, and supplement them with sugar cubes in the loco itself.

Brian

1) First Ideas: Help Designing Dbl-Deck Plan in Dedicated Shed
2) Next Idea: Another Interesting Trackplan to Consider
3) Final Plan: Trans-Continental Connector
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