# Best way to enclose Sound System Speakers?



## noela (May 22, 2008)

I know that there are several schools of thought on what should be done with speakers for sound systems to get the best sound.
I am putting this out here to see what actually works the best, rather than just acoustical engineering.
I have found that not enclosing the speaker is definitely not the best way to go, because the sounds go everywhere, and not necessarily directly out from the speaker, in some cases, making the car or engine that is holding the speaker a echo chamber. 
I have used fiberglass insulation and packed it around speakers, when the chamber is isolated (as in the fuel tank application). I have custom made cardboard enclosures for installations in freight and passenger cars. I have seen and heard the "hard" type enclosures (plastic, wood, etc.) and they seem to work well also.
What is your preference? How well do you like the "plastic" enclosures (could be PVC or other)? How about making your own out of ABS plastic?
Thoughts and directions, as always, are appreciated.
Thank you.


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## Pete Thornton (Jan 2, 2008)

Noela, 

The speaker in my mikado tender is facing upwards, with holes drilled in the floor to let tyhe sound out, so I'm essentially using the back of the speaker. The tender is brass and otherwise enclosed.


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## Chrisp (Jan 3, 2008)

I used a PVC tube to good effect on a loco project. The tube really enhances the "depth" and lower end range of the sound.

I posted an image of this project on the Forum here http://www.mylargescale.com/Communi....aspx#7442


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## Greg Elmassian (Jan 3, 2008)

I think there was a recent thread all about this that would also be worth reading. There was a lot of information about the size and rigidity of the enclosure. 

Search might turn something up. 

Regards, Greg


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## Dean Whipple (Jan 2, 2008)

a quick way is to glue a foam cup to the back of the speaker......works great........


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## noela (May 22, 2008)

I haven't found a preponderance of information on this subject, and the responses have been great.
For the Doodlebug project that I am doing next I will be using a QSI 1.77 in. speaker, and will have to fabricate an enclosure out of ABS plastic, as I have determined that there is only one really good place to put this as I need most of the rest of the room for the battery and electronics, without marring the visible interior to make this unit completely self contained.


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## Martino2579 (Jun 4, 2008)

I have used pill containers - or tablet containers, or whatever they are called. The little brown/orange pots that medication comes in from the pharmacy! 

Cut down to the right length and then mount the speaker on it with bathroom sealant. 

I've been using 1" speakers and it works a treat.


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## Jim Agnew (Jan 2, 2008)

I use various size plastic cups that condiments such as butter are packaged in. A 15oz. container is a good fit over a 3" speaker. I use silicon sealant to glue the cup to the speaker.


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## Greg Elmassian (Jan 3, 2008)

Search "speaker enclosure":

*http://www.mylargescale.com/Communi...spx#158948* 


Nice discussion... search is not all that tough... not always perfect, but usually worth a try.

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

After all that, no room!


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## Torby (Jan 2, 2008)

I used a pipe cap once. Worked pretty well.


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## mgilger (Feb 22, 2008)

I typically go through a dozen cans of spray paint each year. I use the discarded caps to put on the back of the speakers. I cut a small notch out to pass the wires through, then use a glue gun to attach the cap. Seems to work good. 

Mark


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## grandpopswalt (Dec 27, 2007)

Using a rigid cup or cap enclosure should certainly improve the sound quality and volume over just attaching the speaker to the tender floor. Has anyone tried a tuned port in the enclosure? If it works for such a small speaker it could improve the low frequency response. 

Walt


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## Greg Elmassian (Jan 3, 2008)

Yep, tuned port was also discussed on the other threads. You need a speaker that can handle it of course, because it allows greater cone excursion. 

The more rigid the enclosure, the better bass you get. Bass is the hardest to reproduce in our scale. I run the largest (and highest quality) speaker I can fit, then the enclosure can also be bigger. 

Regards, Greg


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## pimanjc (Jan 2, 2008)

To mount the speaker [from JonB.] in my brass K-4 the front coal doors were removed and a speaker grill was made from plastic.










Then the back of the speaker was covered with a portion of a styrofoam cup.









I am very pleased with the results. The forward mounted speaker makes it seem like the engine, not the tender, is producing the sound. On Youtube, do a search for "pimanjc" and there are several videos of the K-4 with good demonstration of the sound results.

JimC.


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## Greg Elmassian (Jan 3, 2008)

On my mallet, the tender was so far from the cylinders, it sounded funny. Put a down firing speaker at the cylinders, bored a large hole firing downwards and it really sounds realistic, put a second speaker inside for more bass. 

Regards, Greg


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## RimfireJim (Mar 25, 2009)

Posted By Greg Elmassian on 06 May 2010 08:26 PM 
On my mallet, the tender was so far from the cylinders, it sounded funny. Put a down firing speaker at the cylinders, bored a large hole firing downwards and it really sounds realistic, put a second speaker inside for more bass. 

Regards, Greg 
That's something that's bothered me about a lot of the large scale steam locos I've heard on other people's layouts. I've been around enough real, full-size steam locomotives to know how they should sound, and when I'm standing trackside with a scale loco trundling by and the sound is clearly coming from the wrong end (and usually sounding like it's inside a plastic box, to boot), any sense of realism is destroyed. This is not nearly as much of an issue in the smaller scales where the error is a smaller proportion of the listening distance.

On another large-scale forum, I asked if anyone had experimented with using a passive crossover circuit (filter) to separate the treble and bass and used a small speaker near the stack for the former and a large speaker in the tender for the latter. Didn't get much response on that one. Seems to me there is a lot of opportunity for improvement over the typical installation.


It sounds like those of you who are using plastic boxes or foam cups for speaker enclosures are happy with the results, so if it works for you, fine, but I have to say that those kinds of materials are far from what a speaker system designer would use. You want enclosures with mass and rigidity to get the maximum from your speaker, especially in the bass range. This explains some of what's going on: http://en.wikipedia.org/wiki/Loudspeaker_enclosure


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## Greg Elmassian (Jan 3, 2008)

I believe passive crossover, or even a simple high pass on the tweeter would be fine. Put a tweeter somewhere in smokebox, woofer somewhere else.... 

Of course a real crossover would be better. And yes, I keep mentioning something more rigid, but not many people notice the bass component, just lower midrange... 

Regards, Greg


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