Sugar Cube Speaker Endoresment
....from a Soundtraxx forum
[soundtraxx] Re: Speaker sound chamber shape
As I always do on this list, I pay close attention to the proffered wisdom, such as this rich thread on how we choose and install the best speakers for our miniature installations. What is obvious is that the solid acoustical science that lies at bottom of what we wish to do is only a shadow under all the not-so-solid applied art that we must apply to reach our individual sound goals. In this regard, I am keenly interested in the science, but am fairly relaxed in how rigidly that science is applied to get the results that are pleasing to me.
As perhaps mentioned before (I apologize if repeating), I have been on a long program of upgrading operating characteristics and installing sound in a lifetime of my own valued brass locomotives- most finished, and a few fine plastic ones. This has been long enough that I am now contemplating sound replacements in some of my early DSD/DSX installs, and now perhaps even some early Tsunami installs. Here are some relevant speaker choice observations:
1) I have made speaker enclosures out of most everything, and my ears do not discern (or perhaps care about!) significant differences between them. Some of my most successful enclosures have been made from laminated paper (Strathmore/Bristol Board). I seal the paper with whatever paint or lacquer that is handy. The high base speakers have been a standard.
2) I stopped worrying about “how to let the sound out”., after years of worrying about it. The sound seems to find its own way out; and in the tender, the sheet sides seem to transmit (as Mark Gurries has commented).
3) I have never, ever been satisfied with a silent smooth soundless steam locomotive trundling along into view towing a chuffing, tolling, whistling, steaming, clanking, and squeaking TENDER. However, like everyone else, I put up with it because the alternative was no sound at all (some of my most beloved locomotives remained without sound because I simply could not enjoy such sound misdirection as tender speakers engender.
4) The sugar cube speakers (there must be a better name!) have been revolutionary game changers. Great sound (to MY ears) in the smallest of packages.. Although I know never to way never, I no longer use any speakers but the sugar cubes. Any paper cone speaker problem is solved with a sugar cube install- usually in some more appropriate place. I have absolutely stopped any and all tender speaker installs.
5) For several years, I routinely have been installing sugar cubes in the smoke boxes, behind the door and in front of the weight. Some I have done in pairs, others as singles. I prefer the larger singles to paired smaller cubes. Only a few times have I had to remove small amounts of weight to provide room. I spent a lot of sweaty time meticulously opening up the exhaust stack opening to let the sound out. The overall results have been quite good, superior (superior!) to tender sound, but again, creating opening for sound egress, e.g. the exhaust stack, was a useless task that made no discernible difference.
6) In one instance (a large 3-½ lb. C&O H-8 2-6-6-6), the speakers were placed on the forward firebox wall facing to the rear. The sound quality is terrific, but….the sound is also projected noticeably to the rear (begging for a change!).
7) On my most recent, and (to my mind) my most successful installs, I have moved the speakers facing toward the ballast from above the drive line. I have done this on one very large locomotive, and two very small ones, and both I and critical visitors note how clear and “locomotive-centric” the sound is.
I do NOT ever remove any weighting.
Almost all of my sugar cubes are Knowles with 3D enclosures from Streamlined Backshop- which has a remarkably varied enclosure collection. The enclosures are beefy enough to be able to do significant shaping to fit curved areas etc. I have cut some enclosures down for clearance reasons, noting no obvious adverse sound changes. I alter them with styrene or paper. I fasten the speakers to the enclosures with fine beads of flexible Barge cement.
I have a collection of the iPhone4 speakers, but have yet found no opportunity to use them in a place where they will fit.
Among all the things I do not know in all of this is exactly what are the limits of enclosure depth, etc. for the sugar cubes. How shallow can one go? There are places where I would favor one larger cube with a shallow enclosure rather than two smaller cubes on standard enclosures.
The sugar cubes, coupled to small decoders, and 32/36 gauge wiring have together revolutionized sound decoder installations.
Denny
Denny S. Anspach, MD
Sacramento, CA 95864