Theoretically, I'd say upward firing through the coal laod, whatever it is, would reproduce high freq sound better, BUT...
Blackstone uses a solid coal load, with the underframe having openings beneath to allow the sound out by downward firing. My Blackstones all sound great, so I suspect in real life it makes no discernable difference with a good install that's properly enclosed.
I have thought of spraying the foam "coal" loads I made with 3M 77 adhesive and rolling them in coal. However, that tends to be messy and shed. It would probably work and look good as far as covering the speaker, so is probably worth experimenting with. Not enough difference to make it worth the potential messiness for me. The foam by itself looks pretty darn good.
375 also has one of these "coal" loads and it looks pretty good at 3'.
Mike Lehman
Urbana, IL
Thanks Mike, I didn't expect to see an answer here, after I moved my question to Rich's thread on where to put speakers.
I can see installing the speakers under the tender's coal load maybe being a better orientation of the speaker, for sound. Do you and others who have done so, feel this to be true?
Most of the time, I have never thought the plastic coal load molded into the tender, to look much like real coal and have added Woodland Scenic’s coal to make the load look better. The coal is glued into the tender using the same method I use for securing ballast and other scenic elements. I can see this being a problem with having the speaker pointed up through the coal. Certainly, you would want to glue the coal down, previous to installing the speaker. Has anyone tried this out? What did you do and how did you do it?
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
Mark,
There are various formulas for this, but the basics are usually enough given the size of these things. I think most people go for twice the volume required to enclose the speaker. Someone else will probably have better terminology, my CRS is not helping right now.
The Soundtraxx premade enclosures are an example. The simplest is just the bottom ring that the speaker attaches to and a back to seal it up. That bottom ring is just tall enough to clear the back of the speaker and wide enough for the speaker to set in (plus seals around the rim better.) You get three more rings IIRC that allow you to increase enclosure volume. One extra ring added, i.e. ~doubling the volume, gives pretty good performance.
So measure you speaker then douible the size of the box that wiuld enc;lose them and you should be close. Obviously, sometimes don't fit that way, so you have to settle for less than ideal.
Post moved to the thread on speaker placement in this forum, which is more probably where it should be.
BTW, I just posted some pics of the speaker and enclosure I built in the tender of my K-36 in a thread Rich started asking a similar question about enclosures.
http://cs.trains.com/mrr/f/744/p/243590/2712970.aspx#2712970
I'm totally OK with speaker stuff.
The speaker should be held tightly, with some form of gasket or sealant to ensure no leaks. If you use Soundtraxx speakers, I think they even make nice little sticky gaskets that fit for this purpose. Others may have them too.
Here's the link to what's available from Soundtraxx:
http://www.soundtraxx.com/access/baffles.php
O.K., wood it is! This fits with my supplies, I have lots of wood and like working with it. What can you tell me about installing the speaker: Should it be held loosely in the enclosure or secured somehow? How much room should be allowed around and on top of the speaker? The tender shell in this case is plastic with a plastic chassis underside. There is a lead weight I will reinstall, after I see if I have enough room for it.
Mike, are you o.k. with this small trip into speakers? as I can surly start a thread on this?
Here's my thoughts based on experience and experimentation.
I've made enclosures from plastic, wood and lead. The wood enclosures sound the best, even though lead has a zero resonant factor. On average, the plastic enclosures that come with speakers should have about twice the volume they do for optimum efficiency of the speaker. I beleve they are made "too small" in order to fit the largest speaker in the smallest space.
I've netted way better results using a slightly smaller speaker with a bigger enclosure in the same given space.
Lastly, round speakers are way more efficient than rectangular versions. The cone movement is equal across the surface of a round speaker. With a rectangular speaker, the cone movement is restricted to the amount given by the narrow side. Two 16mm round speakers will give better sound reproduction than a single 16mm X 34mm speaker in a like sized enclosure.
That's been MY findings based on a lot of experimenting.
Now .... how about them wheel wipers ? ....
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Cantankerous, but not obnoxious...maybe that is what it is
Plastic works well. I've also seen wood work.
Mike, I was just "blowing smoke up your skirt" a little, the reality is you are one of the most cantankerous model railroaders here!
So, if it turns out I need to build an enclosure, what’s the consensus on the best material to build them out of?
NP2626You must simply bring out the good manners in people!
My objective isn't an apology. I don't think there was anything really here to apologize about.
Thread drift tends to happen unless you gently push back against it. And I really try to relate to things as being a member of a community that encourages people in any forum I'm on to interact, not counteract. The internet doesn't inherently provide much in the way of self-monitoring, so I think you have to intentionally consider how your words sound to others as well as to appreciate that things that irritate you often aren't personal.
So I tend to explain my concerns but rarely take the things that spark them personally. It makes it easier to disagree and still count folks among those who are willing to have a good conversation just as much if not more than a good argument. Lord knows there's too much of the latter and never enough of the former.
Randy has good points on this, Mark. I will say that most speakers sold for this purpose now have a corresponding enclosure available at very nominal cost and this is often the low road to good performance. Otherwise, it's a lot like building your own stereo speakers. Looks simple, but the more you know about theory and materials, the more complex it can be.
I remember someone posting about experiments with that, making enclosures out of different materials. The denser and stiffer the better - you don't want the enclosure flexing with the sounds. I no longer have a link, but the experiments included enclosures from various plastics, metal, wood, and I think even a lead one.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
So, I don't believe George from Soundtraxx knew I was talking about a brass model, when he stated that I could use the tender shell as a speaker enclosure, as the materail the tender is made from was not specified.
This does beg the question, what is a good material to make speaker enclosures from?
Mike, not meaning to undermine your ideas about providing extra contact. More contact can't hurt and because sometimes room is very limited in the loco; or, tender, better contact with the track is maybe the only alternative.
However, how is it that you get people to apologize after they derail; or, contradict the thrust of your threads? You must simply bring out the good manners in people!
The other Mark, again!
I went back to see how you are now installing wipers, thinking I was going to see some real innovative engineering. Then it finally did dawn on me that your smarter than that and don't install wipers anymore, you just install the Current Keeper, Stay Alives, ect.
Other Mark
Mark R,
No, definitely no hard feelings. I know you didn't intend it as a hijack or put down. I just wanted to focus on the wiper aspect of things here, because it was a specific question about them that started this.
Looks good. Nice neat job, too, compared to my road-weary examples, which didn't look all that hot when newly done.
NP2626Mark, Can I ask you to show us how you do it now?
Mark/NP2626,
I think (other) Mark means that he does this sort of thing with keep-alives now. But I don't want to presume that.
NP2626 Mark, Can I ask you to show us how you do it now?
Mark, Can I ask you to show us how you do it now?
Read my first response in this thread ....
Again, my apologies for the hi-jacking Mike. Just so there's no hard feelings, here's a couple pictures of how I used to do it ....
Mark R.I'm sure that would be fine if the interiors were DESIGNED for sound - the majority of brass aren't.
Precisely my point, thanks.
Mark R.Sorry for veering off-topic - will save further discussion for a different thread ....
Yeah, I didn't start the thread with the idea of making it one-up-manship a la mode. It was to illustrate something for a fellow forum member. This is the sort of thing that discourages people from posting much of anything, because someone jumps in with, "You should have done it differently and entirely better..."
Which usually works better in it's own thread, I'll agree.
Not sounding miffed here, really, but it's a good example to reflect on about why some things inadvertently (I'm sure) rub people the wrong way.
Meanwhile, back at the ranch...
Still hoping for others who use wipers to post up pics of their wiper installs, provided they haven't been discouraged from even bothering.
mlehman Mark R. he whole inside of a tender cavity (sealed or not) is not an ideal enclosure for a speaker. I suspect George thinks that way because Soundtraxx engineers the tender as part of the sound system on the Blackstones. Get away from that and the possibilities are a bit more hazy, especially with brass. But it seems to work plenty fine on my K-27 and C-19 locos.
Mark R. he whole inside of a tender cavity (sealed or not) is not an ideal enclosure for a speaker.
I suspect George thinks that way because Soundtraxx engineers the tender as part of the sound system on the Blackstones. Get away from that and the possibilities are a bit more hazy, especially with brass. But it seems to work plenty fine on my K-27 and C-19 locos.
I'm sure that would be fine if the interiors were DESIGNED for sound - the majority of brass aren't.
Using the entire tender shell as the enclosure would be like mounting your home stereo speakers in the living room wall and relying on the adjacent bathroom to be the enclosure ! Sure, they would work, and probably sound "ok", but it would be far from an optimal installation.
Sorry for veering off-topic - will save further discussion for a different thread ....
Mark R. I've added the TCS Keep Alive modules to many Loksound and Tsunami decoders. They can be added to ANY decoder really. You just have to find the positive (use the blue light wire) and negative (input diode) connection.
I've added the TCS Keep Alive modules to many Loksound and Tsunami decoders. They can be added to ANY decoder really. You just have to find the positive (use the blue light wire) and negative (input diode) connection.
Rich
Alton Junction
Mark R.he whole inside of a tender cavity (sealed or not) is not an ideal enclosure for a speaker.
Mark R.As for finding room in a narrow gauge tender - I've installed a Loksound Micro decoder, speaker and an ESU stay alive module (not to mention lights) in a Hi-Rail truck .... I'm sure they would fit in your tender ! Smile, Wink & Grin
Well, come on down. Have the border patrol call me if there are any issues...I'll have the iron hot, will even put some Canadian beer in the fridge.
NP2626 George at Sountraxx told me I could use the tender body as a speaker enclosure. My guess is that you would need to seal the joint between the body and chassie, to get this to work right. I think thi is because sound from the back of the speaker is out of phase with the soiund from the front?!?
George at Sountraxx told me I could use the tender body as a speaker enclosure. My guess is that you would need to seal the joint between the body and chassie, to get this to work right. I think thi is because sound from the back of the speaker is out of phase with the soiund from the front?!?
When installing a speaker in a brass tender, I always make a separate enclosure to mount the speaker in. The speaker is sealed to this enclosure. I then mount the enclosure / speaker to the floor of the tender. The size of the speaker enclosure is important. The speaker needs to be able to compress the air on the back to some degree to be optimally efficient, otherwise the cone is just vibrating in free air and resonating within the enclosure. The whole inside of a tender cavity (sealed or not) is not an ideal enclosure for a speaker.
As for finding room in a narrow gauge tender - I've installed a Loksound Micro decoder, speaker and an ESU stay alive module (not to mention lights) in a Hi-Rail truck .... I'm sure they would fit in your tender !
Mark R. I started using TCS Keep Alive modules. Solder two wires and no more need to install wheel wipers and all the extra wiring !
I started using TCS Keep Alive modules. Solder two wires and no more need to install wheel wipers and all the extra wiring !
Yeah, that is possible. I won't argue with George, he knows his stuff.
He's absolutely right about the need to isolate the sound coming from the back from that coming from the front, which is what the speaker enclosure does.
But considering how many little openings there are in the typical brass tender, it could be a bit of a challenge. Sometimes things tend to rattle and buzz with brass, too. That can all be overcome. The sealing of the tender shell to the frame is probably the trickiest part. When I go to shoving all the wires, etc in to button everything up, having gooey stuff or a gasket to worry about would probably drive me nuts at that point in the process.