A & B unit sound in both?

Model Railroader Electronics and DCC
1

I picked up a pair of HO Stewart (Kato drive) F7 And B units, both DC powered.

I plan to switch them to DCC and add sound. I like the TCS Wow sound decoders, naturally i at least need a decoder in each locomotive but should i put a sound decoder in each unit? or would you put a sound unit in just the A unit and a basic function decoder in the B unit. Naturally cost is one consideration, but i was wondering if you can distinguish the engine sounds in two locomotives MU’ed together. I would not need lights on the B unit (that i can think of) and horn sounds would be unnecessary too.

I appreciate your thoughts.

2

Nope. Not worth it. I have an almost identical setup, except mine has an econami in the A unit instead of a WOWsound. The rule of thumb as I have heard it is 1 sound decoder per consist. My exception to this rule is differing prime movers…

3

I’ve got a couple of sets of ABBA F’s, all with sound. I can definitely hear it. Four of those bad boys, all togther, is awesome.

Around here, ALL units in any consist will have sound. Or none will.

I can hear the difference.

Ed

4

I have a Stewart F3 A&B. I put loksound in the A, but the B is a dummy. Can sound be added to a dummy and is there a cheaper option than a sound/motor decoder?

If so, the jury has voted 1 to 1

5

I have an HO A/B F3 set up with LokSound decoder and motor, speaker in the A and motor and speaker in the B. Close coupled with a six pin inline connector hidden in the diaphragm. Called a lash up mode. Works just fine.

An A/B F7 set up with Tsunami and speaker in the A and same in the B. I did it because I could.

Love running them in a ABBA set pulling a long freight.

Rich

6

Rich So 1 decoder runs 2 motors? I did consider putting 1 big speaker in the B unit. I wasn’t sure I was up to good looking plug installation.

7

Well i appreciate all the replies and thoughts.

8

I can think of 2 examples with LokSounds. A key aspect is whether the sounds are in sync.

The LokSound E unit sound files were improved a few years ago, adding a 2nd prime mover sound, and the update is neater.

For consist of identical locos, same sound files, there is a CV that can be tweaked slightly from 128 on one or more locos to change the playback speed. So a loco set on 128 paired with one at 127 is not in sync, excepting when the one sound “passes” the slower one again, so the sound is not just louder as it would with two locos in sync.

A neat feature, so I equip each loco with best achievable sound.

9

Yeah, Paul covered it. Not sure if WOW Sound can do the same thing, btu Loksound hs the feature to set each decoder slightly out of sync. The sounds from the two will be VERY noticable if you do that. Otherwise, they will not be terribly distinct.

–Randy

10

I had a large room layout. I ran several different consists, but I almost never put two sound engines together. I was happy enough with one sound engine per consist.

11

If the engines are not sound-ready - don’t have a built in speaker enclosure - it’s often easier to fit a big speaker in the B unit of an A-B F-unit set. If they both have speaker enclosures so conversion would be easy, and you have the money for two sound decoders, no reason both couldn’t have sound.

I have a couple of A-B sets where the B is a dummy. I connect the engines with a drawbar (you can get them from Stewart). For sound, I just run two wires back through the openings for the windows in the end doors and put a large speaker and enclosure in the B-unit.

12

Sounds good - now all you need is lots of money! [:o)]

13

I have thought about this, and I completely agree.

Ed

14

I have several AB lashups, with a second speaker from the A unit decoder to the B unit, connected through the door window openings and hidden by diaphrams. A couple are hard wired, and a couple are connected with micro connectors. I have never had a decoder burn out or damaged by hooking up two speakers. Some OEM installs have two speakers in a single unit facing each other. That’s your cheapest option. You can put the second speaker in a powered or dummy B unit if space is available.

15

I was working wondering if one decoder can be made to drive 2 speakers one in each unit.

16

Sure. Impedance matters though and that can change depending if they are in parallel or in series.

This article addresses adding multiple speakers. You can buy minature plugs to connect the A and B unit.

http://mrdccu.com/curriculum/speakers.html

17

I did it because I could.

First setup, one deocoder in A, motors and speakers in series, A and B.

Second setup, two decoders, A and B, pricey but I liked it.

I use to run a Bachmann two motor 44 ton with both motors in series with a DZ125 decoder just fine.

Rich

18

I didn’t see it in the article, but I may have missed it. If not, as the article said, the outputs of the decoder do not like less than 4 ohms.

Speakers come in 4 ohm, 8 ohm and 16 ohm, so any single speaker will work fine.

Going dual speakers, you need to be careful how they are wired and the ratings of the speakers. In series, just add the impedance together.

The foumula for parallel wired speakers is the product of the two divided by the sum of the two.

So if you have (2) 8 ohm speakers, 8*8 is 64 divided by 8+8, or 64/16 = 4, you are good.

For 16 ohm speakers, 16*16/16+16 = 256/32 = 8 ohms, also good.

However, for 4 ohm speakers, 4*4/4+4 is 16/8, only 2 ohms, sionara outputs in the decoder.

If you have 4 ohm speakers, you must connect them in series.

19

Only if you are using Loksound decoders. Any other brand sound decoder should not use less than 8 ohms total load. Loksound decod

20

I have an Intermountain F-7 equipped with a Tsunami sound decoder matched to another Intermountain loco without sound.

There is a reverberator setting in the Tsunami that when properly adjusted can mimic the sound of two locomotives.

There is a screen in DecoderPro for the reverberator. The image of the screen I have is less than clear, however the CV settings are as follows:

CV 161=7

CV 162=255

CV 163=255

CV 164=0

CV 171=255

All of the above are courtesy of Bruce Petarca.