I have found six brands of sound decoder that work well in N scale.
MRC.
I don't use many of them for many reasons. The sound volume can be improved by replacing the speaker, but the rest of it is what is.
MRC also makes a sound-only decoder that is a curious item and the price is right. It is too big to fit in an N scale locomotive with motor and all but can be squeezed into a hollow shell (like a sound box car) if tilted diagonally. Quality seems to be good on the these also. I have used enough for long enough to create a reliable sample size and not failed one yet... knock on wood. In fact, the first sound car built used this decoder and the owner reports that it still chuggs right along two years later... literally.
PROS: Good sound quality. I really like Sounders
CONS: Goofy CV logic and control design (completely non-standard). Quality. Little or no light options (at least on the stuff I tried).
Digitrax SDN series.
Low cost, programmable, digitrax motor and light control. Pretty nice for what it is. The sound volume can be improved by replacing the speaker. My only complaint here is the lighting control doesn't work the way I want and the lack of files available to program. I usually settle on something that is close. Anyone know of an aftermarket sound file dealer? In many cases, close means that it is a steam or diesel engine. The compact size of the SDN144PS allows it to be used in many applications. The other models I've used work equally well.
You may find references to the "Digitrax Stall". I have seen it a couple times now. Basically, when you blow the horn, the loco slows down. The only way to correct it is to turn off BEMF.
Also be sure to include the capacitior in the install. 100uF seems to be enough to prevent most problems.
PROS: Programmable, OK motor control, price.
CONS: Poor function control and mapping. Lack of sound files. Documentation.
ADENDUM: I have finally encountered the dreaded Digitrax Stall. Refer to Digitrax Stall and Lurch Page for more information about this.
Digitrax Series 6 SDN and SDXN series.
I haven't been able to try one of these yet but big D has made a few improvements worth noting.
They have released the Series 6 firmware that most notably improves the resolution of the motor control. If they implemented it well, this should be a noticeable change. The story was this would also fix the "Digitrax Stall" issues... TBD.
Both models feature a quick connector for adding a Power Xtender keep-alive device.
The SDXN model incorporates a 16-bit processor so the sound quality should be improved.
The SDXN model is perfect sound cars since it has 8 loco options pre-programmed.
I do have to rant about one thing... They added a bulky JST connector to this release! Why? It's hard enough to find space in an N scale install without huge hunk of plastic connector to work around. But I am sure there was a reason...
PROS: Programmable, motor control, price.
CONS: Poor function control and mapping. Lack of sound files. Documentation.
Soundtraxx TSU750 Tsunami Micro et.al.
Excellent sound quality but it costs more. Excellent motor and light control. A big problem here is heat. They seem to be tempremental unlike the full-size version. Be sure your install includes the capacitor and a way to get the heat out. The other issue is the size limits it's use to tenders and carbody type locos with frame work.
PROS: Quality and design.
CONS: Size and heat. Motor control and electronic chuff matching are hard to get right.
Loksound Micro V3.5 et.al.
Premium sound at a premium price. Excellent motor and light control. The board is small enough to fit in an early Atlas GP7 hood with some frame work. This chip is also programmable which makes it versatile and customizable. Big problem here is speaker options. This board uses a 100 ohm speaker which limits options.
PROS: Quality, size, design, programmable.
CONS: Speaker rating.
ESU Loksound Micro V4.0 et.al.
Premium sound at a premium price. Excellent motor and light control. The board is small enough to fit in an early Atlas GP7 hood with some frame work. This board is also programmable which makes it versatile and customizable. This version is now rated to use a traditional 8-ohm speaker.
The v4.0 LokSound, Select and LokPilot have really raised the bar on DCC lighting and function control. The new version includes the ability to incorporate logic statements (if-then style) to conrol how a funtion responds, the ability to assign multiple effects to a single output, and excellent alternate phased lighting and control for ditch lights and strobes.
This decoder has lots of sound options, excellent features, and an overall superior design. ESU is the king of sound and worth the premium.
PROS: Quality, size, design, programmable.
CONS: ??? Sure wish the board was about .020 narrower.
ESU Loksound Select Micro
Premium sound at an affordable price. Excellent motor and light control. The board is small enough to fit in an early Atlas GP7 hood with some frame work. The rub here is this board is NOT programmable which makes it more of a PnP-type sound decoder. You basically get one sound file with a couple of minor variations of the prime mover. You cannot edit the horn or bell or other sounds. This version is also rated to use a traditional 8-ohm speaker.
The v4.0 LokSound, Select and LokPilot have really raised the bar on DCC lighting and function control. The new version includes the ability to incorporate logic statements (if-then style) to conrol how a funtion responds, the ability to assign multiple effects to a single output, and excellent alternate phased lighting and control for ditch lights and strobes.
This decoder has a good choice of sound options, excellent features, and an overall superior design. ESU is the king of sound and worth the premium.
The ESU LokSound Select line is one of the best values on the market today.
PROS: Affordable. Quality, size, design, programmable.
CONS: ??? Sure wish the board was about .020 narrower.
Zimo MX646, MX648, et.al.
A very high quality decoder at a great price. They are another example of outstanding motor control and excellence in engineering. The MX648 is the smallest sound decoder available and will fit in some amazingly small locations.
Loading sound files with the new MXULF has been very easy and very reliable so far. They are still working on a USB connection though so loading files requires use of a memory stick.
PROS: Quality, size, design, programmable.
CONS: Limited selection of sound files and sound editing software still under development as of this writing.
CT Elektroniks.
No experience with it but it looks like the smallest sound decoder on the market and requires yet another model of programmer. Also, a european model so not sure if there are any US type sound files available. I have read that the documentation is very cryptic making it a challenge to use.
Application.
Almost every application is different so there is no clear cut answer as far as "how to". The key to good sound in any scale is speaker size and installation. Bigger speaker = better sound. Baffled/sealed speaker = better sound. It is more important in N.
Be sure to check out my speaker selection. I offer a 13x13mm and a 15x15mm speaker that really rock N scale.
I put a stock SDN144PS in a J611 recently. The stock speaker did not generate enough volume to overcome the noise of the mechanism. To make matters worse, the volume was just loud enough to make the mechanism "seem" noisier since now you could hear some other noise in the background that couldn't overcome the engine itself.
I like the SDN for the price and the programmable feature but it has some real quirks that make hard to get the kind of results I like.
I really like the sound quality of the TSU-750 but I have to do a lot of work to keep it cool and it is just a shade bigger than the ESU LokSound Micro or the SDN144PS.
The LokSound Micro V4.0 has a couple of firmware quirks but is otherwise right. It really is the complete package now.
The other option is to build a sound car that is consisted with the engine. This is a convenient solution and much easier to do. It is also flexible and allows you to add sound to any consist, any time... especially if "close enough" is good enough for you. Trickier for the DEA (Diesel Engine Aficionados) but still possible.
Regarding multiple decoders vs single sound decoder when running M.U. sets, it does make a difference. It is pretty sweet when a pair gets out of sync and you become keenly aware that there is more than one engine running. It is possible to kind of simulate this with the TSU boards as it has an onboard equalizer capable of adding a reverb effect to the sound file.
Preference? The one you want me to install (he says with a smile). See cons above. What can you live with.
I have recorded many examples of the above and posted on you-tube for your consideration. Don't mind the video quality. I'm an engineer not marketing! Adding new examples regularly.
Be sure to visit our YouTube channel at Streamlined Backshop Services to see video demonstrations of some my work.
