DCC Sound

[MickMoignard]

I'm Mick Moignard, here from 11 to 12 and 2 to 3. Questions here....

Have you been able to take a look at my slide deck 8 things for a good sound install at https://www.scaleforum.org/wordpress/wp ... nstall.pdf? That's the basis of my demonstration at real shows, but feel free to ask whatever questions you have. I'll do my best to help.

[Matt Harris]

Hi Mick,

I've read through the 8 Criteria for a good DCC Sound Install presentation and this all seems rather clear to me.

About the only question surrounds the speaker installation - do you have any other tips and tricks for this?

Thanks for sharing.

Matt H

[MickMoignard]

About the only question surrounds the speaker installation - do you have any other tips and tricks for this?

That's one of those length of a piece of string questions.... Personally in steam locos I always try to get the speaker in the smokebox, or if not, as close as I can. My only P4 steam loco (I actually model Colorado 3-foot in HO Scale), a Brassmasters Black 5 with a resin boiler, has the speaker between the frames just behind the cylinders. I feel that a good speaker located properlyis better than a better speaker in the tender, for example.

The thing you must do is make sure that the speaker is properly enclosed. For sugar cube/mobile phone speakers, that means enclosing the diaphragm side. Thet do not work properly if this face is exposed. I've seen several locos where the owner said the sound was terrible and what Icould I do which has naked speaker drivers in the loco, no box or enclosure at all, and yes, all they did was buzz.

Do you have any specific issues, models, speaker types that you're having trouble with?

[Matt Harris]

Do you have any specific issues, models, speaker types that you're having trouble with?

Mick,

I don't have any specific issues per-se, rather some general principles as a 'what to watch for'.

Mostly, it is with the installation into diesels, both main-line and shunters.

Right now, I do have a Judith Edge Ruston 48DS that I'm thinking of a sound install which might be rather challenging...

[MickMoignard]

It's also worth saying that the speaker should be firmly attached to the model, rather than flapping about. If it is loose, you risk rattles and of course and shorting the connections to the inside of the model.

Another common problem is shorting the speaker leads to the track when installing and testing. Just don't do that, because it will always kill the decoider amplifier. Do be careful...

And if course make sure that the speaker impedance and power capacity match the decoder. If you use a decoder that needs and 8-ohm speaker and has a 2-watt output with a 0.5watt 4ohm speaker, either speaker, amplifier or both will fail quite quickly. Best to double up if need be; two 8-ohm 1-watt speakers in series make a 16-ohm 2-watt speaker, which will be fine for most decoders. just make sure that the speakers are in phase, wired +ve to -ve between the two.

[Matt Harris]

That's all really helpful, thanks

[MickMoignard]

Right now, I do have a Judith Edge Ruston 48DS that I'm thinking of a sound install which might be rather challenging...

I have an HOn3 Fairmont track speeder (think Wickham trolley equivalent) that's about 30mm long and 18 or so mm wide. I'm a Soundtraxx user, but this is so small that a Zimo MX648 was all that would fit, driving a 9*12 sugar cube speaker driver which has no box (no room), just a plate across the mouth. Tiny Mashima motor and lights....

Look under the cab roof, check for space under bonnets with a lump of blutak. Place on the cjassis, insert into body, and then remove. What size and space is the blutak? is it the same size as a speaker? If so, then a speaker should fit there. In P4, look between the frames, too. Lotsa space in there in many locos.

[MickMoignard]

I'll be back around 14:00: keep asking the questions....

Mick

[Matt Harris]

Look under the cab roof, check for space under bonnets with a lump of blutak. Place on the cjassis, insert into body, and then remove. What size and space is the blutak? is it the same size as a speaker? If so, then a speaker should fit there. In P4, look between the frames, too. Lotsa space in there in many locos.

Now THAT is a really useful nugget - thanks!

[MickMoignard]

Another tip not mentioned in 8 things... is neat wiring joints. You don't need to bare more than 2mm at te end of a piece of wire to solder it. That's all you need to connect to a decoder pad, or to solder to a speaker or motor terminal. You just do not need miles of bare wire about. The only exception might be when you want to twist two together that are side by side to get a solder joint and then I would trim it back as well. Remember too that many wire insulations shrink back a bit under the heat. You were also born with the best strippers for this small wire too - your fingernails. 1.2 mm heatshrink tube works with most decoder wires, you can get this from Eileens among others. Having some 1.6m to hand also helps.

[MickMoignard]

And while I'm leaving tips - you can stretch larger diameter heatshrink tube with a pair of needlenose pilers if you need it a little larger. I sometimes do this to make a piece big enough to go over the terminal end of a speaker once it's been boxed and connected. You don't want the terminals shorting onto the inside of your brass boiler.

[peter3292004]

Good morning (afternoon) from the USA.
Thank-you for sharing an excellent presentation.

Regards Peter (7149)

[MickMoignard]

Here's another idea. If you take an 0402 wired LED, encase it in about 3mm of clear heatshrink. amd paint to and bottom so that you have an appriximation of a handlamp. Take a plastic (not metal) figure, and drill from one hand up the arm to the shoulder with a 0.5mm drill. Then from foot up leg to shoulder. Join the two holes at the back of the shoulder with a slot carved with a craft knife or scalpel. Thread wires from lamp up arm and down leg, position handlamp appropriately in the hand. Fill shoulder slot with putty and paint figure. You'll need a 30kohm resistor to make the LED suitably dim.

I have one of these on a piece of clear plasticard. The resistor is on the underside and the wires then spread out in a loop each side, held with superglue. The wires were then sanded clean. Plonked on powered track you have a lookout chap with handlamp to protect a track crew or somesuch.

I have another standing on the back platform of a caboose wired to a function on a Soundtraxx Soundcar https://soundtraxx.com/products/tsunami-soundcar. That decoder's clever automagic consisting, as well as making appropriate clicketyclack sounds also enables me to turn his andlamp on and off from the loco.

[MickMoignard]

Another tip: your soldering iron. I speak often with people who say that they have little success in soldering, and find they're using 18 or 25 watt irons. Such things are a total waste of time. They provide so little heat (and I mean heat volume, not temperature) that the copper wire you're soldering or the brass in the etched kit (remember, brass is mostly copper) draws away all the heat almost as fast as it is supplied, and you have to heat everything up over several seconds to get the solder to start to melt. This is largely why people have such trouble making etched kits with other bits falling off; soldering iron just not powerful enough to make the current joint well enough fast enough.

Use a 50W minimum iron - termerature controlled is good too. Such a thing will make you able to get heat volume in quickly to get a decent joint made quickly whether you are soldering wire, electronic parts or etches.

For use on electronic stuff, try and make sure that the iron doesn't leak electrically - some leak several volts at the tip, which is not alwasy electronically good. Irons designed for electronic use will be fine. I used Antex TC50 and later one of their soldering stations with no problems for years. I now use an Ersa Icon-1 (shout out to Kevin Wilson for the tip) and love it. Hugely powerful, and measures the temperature at the tip. 150W over short periods and fully military approved. Great for decoder installs but also man enough on structural stuff that I use my RSU a lot less than I used to.

And when soldering anything even vaguely electrical or electronic NEVER EVER use any flux other than rosin flux. The type of stuff that you slosh all over etched kits will wreck your decoder, LEDs, speakers, PCBs and everything else withing a couple of months. Just don't...

[MickMoignard]

I'll check back later on; bye for now.

[MickMoignard]

If you have any more questions, can I suggest you direct them to me at mick@mickmoignard.com as I might not be very assiduous at checking back here....

Cheers

Mick