Where to get 8mmx12mm speaker

[jdcolombo]

Basically, all these small speakers sound the same at a given size with a proper enclosure.  None of them have any real bass, and all of them begin to roll off below 800hz, and then fall off a cliff below 500hz.  Larger sizes (11x15, 13x18 and up) will do a bit better, and better as the size gets larger. 

As Peteski noted, the problem with the factory speakers isn't the speaker, it's the enclosure, or lack thereof, or lack of sealing thereof.  I understand why it is the way it is: these things have to be assembled, so the manufacturers have traded sound quality for assembly ease.  But I have yet to come across a factory sound install (even in HO scale) that I couldn't DRASTICALLY improve by using a proper sealed enclosure with whatever size speaker will fit.

John C.

[tehachapifan]

Basically, all these small speakers sound the same at a given size with a proper enclosure.  None of them have any real bass, and all of them begin to roll off below 800hz, and then fall off a cliff below 500hz.  Larger sizes (11x15, 13x18 and up) will do a bit better, and better as the size gets larger. 

As Peteski noted, the problem with the factory speakers isn't the speaker, it's the enclosure, or lack thereof, or lack of sealing thereof.  I understand why it is the way it is: these things have to be assembled, so the manufacturers have traded sound quality for assembly ease.  But I have yet to come across a factory sound install (even in HO scale) that I couldn't DRASTICALLY improve by using a proper sealed enclosure with whatever size speaker will fit.

John C.

Completely agree with all of this except that my lone Atlas N SD45 sample has great sound out of the box. Incredibly robust! As good as any of my custom installs with scratch-built enclosures. No other factory sound unit I've heard comes remotely close to what Atlas did with this particular release.

[jwaldo]

It doesn't help that so many stock locos actively defeat any space that might serve as a speaker enclosure by 'helpfully' putting holes in it. My BLI SW7 has a speaker the size of a pinkie nail in the fuel tank, but it IMMEDIATELY sounded better after I covered up the factory holes to 'let the sound out' of the bottom of the tank.

Thanks, that 9x16 is my go-to speaker and really like it.  I have the 8x15 but haven't used it.  The other two I don't have but will keep them in mind if I have an install where they would work.

Someone on here mentioned a 9x25 (CMS-250903-18SP-X8)  and I ordered a few and like them but so far only used them with a really large enclosure in my HandCab-DC...

.... I'm going to try one of these in a GE U50 and maybe if I like it a couple larger engines.  In the video the speaker in the boxcar is the 9x16 that you linked to.

I know next to nothing about reading the specs but from what little I've picked up on here thought they weren't great but still liked the sound.  John posted info on the frequency response curve and from what he said maybe these aren't so bad in the low freqences as they look pretty good down to 600 or so.  Am I reading and interpreting this right?

https://www.sameskydevices.com/product/resource/cms-250903-18sp-x8.pdf

Sumner

I'm excited to see how this turns out. The U50 has so much space inside that you could fit a huge speaker like that PLUS a really optimized resonance chamber in there without having to mill anything off the frame.

[Sumner]

.....I'm excited to see how this turns out. The U50 has so much space inside that you could fit a huge speaker like that PLUS a really optimized resonance chamber in there without having to mill anything off the frame.....

I think I'll take a break from my CAD work on trestle supports and work on this U50 tomorrow.  One problem is the way that insulated frame screw protrudes up....



.... at the back of the frame (to the left where the decode is installed above).  Kind of 'screws' things up.  I just tested the LokSound for fit and can get it in up front where the forward light is above with just a touch of milling there.  I think I can mill the back of the frame and drop that frame screw and insulator down some.  First though I'm going to design a speaker enclosure that would saddle that screw and see what I think about that.  I'm going to try the 9X25 speaker first.

I have no idea how I'd design an "optimized resonance chamber".  Any suggestions on that?

Without milling the top of the rear frame down some there isn't that much height there, about .120.  If I can get that screw further down then the total area without milling would be 1.600 x .430 x .220  (LxWxH) inches that there is to work with.  The speaker takes up .990 x .360 x .120 inches up of that plus wall thicknesses of the enclosure itself.  As you can see above I have .700" to work with past the speaker that can be full height.

I'll work on a basic enclosure tonight or first thing in the morning and check back to see if you or anyone else has suggestions.....thanks.

Sumner

P.S.  More U50 pictures without the shell on some previous installs here....

https://1fatgmc.com/RailRoad/Decoder-1/page-6.html