Where to get 8mmx12mm speaker

[rodsup9000]

  I'm converting almost all my locomotives on the my layout to ESU.
About half will have sound and the others will have LocPilot's.
 I need some good quality 8X12 speakers for the best price.

I've been using these from DigiKey (thanks @peteski for recommending them) for my FT and F units.   

https://www.digikey.com/en/products/detail/soberton-inc/SP-1511L-2/9924403?s=N4IgTCBcDaIMoAUC0BGArClAZJEC6AvkA

Thanks

[jdcolombo]

Digikey is out of stock on the Soberton 8x12mm, which I have used a lot of.

But I just did a project that used this speaker:
https://www.mouser.com/ProductDetail/Same-Sky/CMR-12062S-67?qs=w%2Fv1CP2dgqr46ud090%2FyZA%3D%3D

It is a 32-ohm 6mm x 12mm.  I was a bit concerned about the 32-ohm rating until someone (Peteski?) pointed out that the ESU LokSound 5 decoders are compatible with 32-ohm speakers, and I think it sounds better in an equivalent-depth enclosure than the Soberton 8x12mm.  If you want to hear it (I put it in the back of an F7), pm me and I'll find a way to send you a short video of it in operation.

Unfortunately, those speakers are currently out of stock at Mouser and aren't expected back in stock until May 2.   But Digikey has a speaker that appears to have similar specs from PUI:
https://www.digikey.com/en/products/detail/pui-audio-inc/AR01232MS-SC12-WP-R/8021810 

If you want to stick with a more conventional 8x12mm, 8-ohm speaker, Digikey has the following:

https://www.digikey.com/en/products/detail/challenge-electronics/CS12-00P43-02-1X/25557907

I haven't tried this one myself, but its specs look very similar to the Soberton 1208.

John C.

[Sumner]

.....  If you want to hear it (I put it in the back of an F7), pm me and I'll find a way to send you a short video of it in operation.....John C

Any chance of putting it up on YouTube?  If not I also just sent a PM,

Sumner

[jdcolombo]

@Sumner

Sent you the file directly by e-mail.

John C.

[rodsup9000]

  I'm getting ready to install sound into 6 VO 1000'S and saw you used 8X12 in your documentation.





Thanks JD I'll PM youRodney

[jdcolombo]

Yes, I did use the 8x12, but honestly I'd use this 6x12 today (and in fact, probably WILL do that on a couple of VO1000's I'm converting for a friend).

Sent you a direct e-mail with the audio file and another with a link to the video.

John C.

[peteski]

Yes, higher impedance speakers (16 or 32 ohm) will work with LokSound decoders but they they will not produce the same amount of audio power as equivalent lower impedance speakers. That likely will nto be a problem - the decoder's master volume migt have be turned up to get satisfactory volume level.

Here is a link to my post listing a range of speakers available from Digikey: https://www.therailwire.net/forum/index.php?topic=54697.msg750304#msg750304
Those are all the speakers I have actually purchased (some have not yet been used in my installations).  But that list is is over 2 years old, so some of the speakers are likely no longer available, or replaced by other similar speakers.

When choosing a speaker for a project, first thing to consider are the dimensions (including height).  Then if multiple speakers have similar dimensions, choose the one with higher efficiency rating and the widest frequency range.   Of course it is also important to use the largest possible enclosure.

[ednadolski]

https://www.therailwire.net/forum/index.php?topic=58598.0

[jdcolombo]

I had to turn up the volume a bit from what I usually use with an 8-ohm speaker, but it's still only about half of maximum.

I did a quick iPhone video of the F7 chassis with this speaker on it.  It's a bit shaky because I was holding my phone will trying to run the engine, but it will give you a good sense of the sound available.  The enclosure I used was just a simple box made with .030 styrene, 7mm high (not including the base).

I'm probably not going to post that video on YouTube just because the quality isn't up to my standards, but if anyone wants to see/hear it, send me a PM with your e-mail and I'll send it to you via Apple's Mail Drop.  Or I can e-mail you an audio-only file.

The bottom line is that it sounds a bit better to my ears than the Soberton 1208 12x8mm, and saves a couple of mm of width if that makes a difference.

John C.

[Lemosteam]

And now you need a box for that one too, right?

[jdcolombo]

And now you need a box for that one too, right?

Well, gee, that would be really excellent!

But not sure on the depth.  Thinking 6mm but let me do some measurements . . .

John C.

[GGNInNScale]

Hi to all    For a given amplifier, an 8 Ohm speaker will give more audible loudness than a 32 Ohm speaker.  Simple physics.  Power is Vrms^2/Resistance.  The amplifier does not know the load value.  It only knows to put out a certain voltage based on its' input drive signal.  This is "Vrms" since the sound is actually an AC signal.  You can think of it in current terms as well- the voltage is V, the resistance is R Ohms.  So current, Irms,  is V/R through the load (speaker), or Power = Irms^2 * R.  It does not matter which way you look at it.
So, for example, say the amplifier puts out 8 Vrms, the speaker is 8 Ohms, so the power would be 8*8/8 or 8 Watts (huge).  For the 32 Ohm case-  8*8/32 or 2 Watts.   So, since your ear is logarithmic, you would hear about 6dB less sound from the 32 Ohm speaker.  Most people can just detect a 2-3dB change, 6dB is easily heard.   Exactly how much of the amplifier's electrical energy is converted to sound depends on the speaker design, and the coupling of the speaker cone to the air.  This is an entire field of study for the last 100+ years...  BTW- I have been building high end audio and rock speakers since the late 1960s.  Also, I have found OWS speakers to be really good for efficiency, and they are about a dollar each in 4 or 5 sizes for N scale use.

[jdcolombo]

While a 32-ohm speaker indeed will sound quieter at the same output voltage level than an 8-ohm speaker, if the amplifier is capable of supplying sufficient drive voltage to the 32-ohm speaker, you can simply "turn up the volume" to make the 32-ohm speaker louder.  Yes, the 8-ohm speaker would sound louder at that same level, but at some point you reach the speaker's input voltage limit before distortion or blowing up the voice coil.  Or (more likely), you get to the point where it's loud enough, and any more would be overkill.  It's not just a matter of speaker impedance; it's also a matter of amplifier capability, the speaker's maximum input voltage before distortion, and what SPL you want out of it.  And higher-impedance speakers actually are an easier load for many amplifiers because the current requirements for driving the speaker are more modest than for lower-impedance speakers.  Magnepan planar speakers (4-ohm load) require an amplifier capable of a lot of current output to get SPL's that equal 8-ohm cone speakers.  Again, it's Ohm's law: I=V/R, so if you need 20v at 4 ohms, that's 5 amps of current, but 20v at 8 ohms is 2.5 amps.   I remember many years ago the Apogee planar speakers that were a 2-ohm load, and dealers demo-ed them with massive Krell solid state amps that could probably have moonlighted as welding equipment (though my McIntosh MC312 will swing 60 amps, so I guess I shouldn't complain).  This is why some very early sound decoders (e.g., the LokSound V3) specified 100-ohm speakers - the micro-sized audio amplifiers of the day simply weren't up to the current delivery required for an 8-ohm speaker.  They could supply adequate voltage swing at 100 ohms, but not at 32 or 16 or 8 or 4 ohms.  But the amp's circuitry has to be designed for stable output at high impedances, too.

In the end, the only question is whether the decoder's audio amplifier is capable of driving whatever speaker you choose to a volume level that is "loud enough".  The F7 install that I just finished using a 32-ohm 6x12mm ended up with the master output volume level at 140, which is about 2/3 of the maximum value for the LokSound 5.  And it certainly is loud enough for my basement layout room, which is 14' x 32' with a 7 1/2' high drop tile ceiling.  In fact, not sure how much louder I could drive it without causing serious distortion in the midrange, and it might be (probably is) TOO loud for normal operations.  We'll see what my friend says when he picks it up, but I don't think he's going to want it any louder.

John C.

[jdcolombo]

BTW, since we're talking about speakers, here's my favorite rock speaker setup of all time:

[ Guests cannot view attachments ]

The Grateful Dead's Wall of Sound, 604 speakers (mostly JBL's I think), powered by 48 McIntosh MC2300 amps delivering 28,000 watts total.

Wonder what a good recording of an EMD 567B or Alco 12-cylinder 251 would sound like through that . . . 

John C.

[peteski]

Wonder what a good recording of an EMD 567B or Alco 12-cylinder 251 would sound like through that . . . 

It would likely sound (and feel) totally life-like!