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Multi speakers one sound card

2K views 14 replies 10 participants last post by  Greg Elmassian 
#1 ·
While thinking about operating multi diesels off one receiver, I was wondering if anyone has used one sound card to power multiple speakers in lashed diesels? Yea you might not get the sound separation of multiple sound cards, but one sound card should be able to power 2-5 speakers, should it not?
 
#2 ·
I think the only issues you may have are (1) matching the impedance of the sound card output, and (2) having the necessary wattage to drive multiple speakers.

1 - most sound cards I've seen are designed to drive into either a 4 ohm or an 8 ohm load. Finding speakers that will match that impedance, either in series or in parallel, might be an issue. At least it's something you should be aware of.

2 - having sufficient power to drive the required number of speakers is the second issue. You might be able to solve that with a small amplifier circuit, or you might be content with lower volume - or your sound card may be able to handle it.

Again, these are just things that came to my mind. Thought I'd post them so you'd be aware of them. Others here on the forums know a lot more about this stuff than I do, so hopefully they'll chime in.
 
#3 ·
I've put a "jack" on the back of a few of my engines (steam) so I could plug trailing cars into the sound system.

The trick is to keep the impedience at a safe level. Sierras will not tolerate less than 6 ohms if the volume is pushed. The Phoenix cards seem to operate down to 4 ohms.

Depending on the speaker in the engine, I've wired some up so that there is a resistor in the system that is by-passed when the plug is inserted. Granted the resistor reduces the volume a bit with no trailing car, but the volume control makes up for this loss (I don't run them to full volume.)

When the trailing cars are plugged in, they have bigger, better sealed, multiple speakers (even in the trailing car) that can really kick up the bass.
 
#4 ·
it's pretty easy to combine series and parallel to get the right impedance, as Dwight said.

In regards to power, I think you need to get the power output rating of the unit first, some are high wattage like the Zimo, and some are not even specified, like the Revolution.

(I downloaded the Revolution manuals, and Dave Bodnar's review, no power output ratings nor speaker impedance given, so assume 1 watt, 8 ohms to be safe)

Tell us a bit more about what you are thinking Randy. Also, if you are running speakers to multiple locos, think if it bothers you to have the horn and bell coming from other than the lead loco, as per prototype.

Greg
 
#5 ·
This may or may not apply to Randy's question -

I have an RDC-1 and an RDC-3, which, of course, is fairly new. RDC-1's haven't been made in years. In the RDC-3 I put a QSI plug-n-play motor/audio card which is built for stereo. I split the audio volume equally between the two channels and ran two wires between the RDCs. The audio is great, with good Doppler effect. Fun to tell people to stand still as the RDCs pass by.

Sidebar - the two wires have a connector between the cars for easy disattachment, and the RDC-1 is powered by its own (NCE 408) motor board. I suspect the Doppler would be even better if I was running separate QSIs so maybe I'll have the cash to go that route next year. (Are they even available any more?)

JackM
 
#6 ·
This and the receiver question for multi units are both just thoughts as to what might or might not work. I'm no wiz at audio equipment so never thought about impedance or needing an amplifier. As for the horn and bell sounds from the additional locomotives, never thought about that either.

With twenty one steam and diesels, buying radios, batteries and sound for all of them would be a very large expense. Sure I could have purchased this stuff a little at a time while buying the locomotives, but I didn't and I suspect a lot of others didn't either. So I was just wanting to see what others may have done.
 
#7 ·
The QSI has TWO amplifiers on board, one for each speaker. You can direct any of the 32 sounds to either or both speakers, with the digital equivalent of a fader control.

I believe Randy is homing in on the Crest Revolution, which only has one amp/speaker output and an unknown power level.

Randy, it will be cheaper for you to remain on track power, as it seems you have already figured out.

There are DCC decoders that will handle 2 locos, but you will have to watch current draw on USAT locos with a fair load.

Greg
 
#8 · (Edited)
Actually, if the engine and trailing car each have a speaker, it is not really noticable across the yard in a garden setting unless the train is passing right in front of you. On a related note, do you think that people really notice that the steam engines' chuff/whistle/bell comes from the tender rather than the front of the engine?

I imagine it could be more important indoors, especially if the train is passing at ear level.

What would be weirder is if say the A and B units are each equipped with their own sound card and you leave the horn and bell turned on in the B unit because the horns and bells would not be in "sync" (as they are if you just use one unit with multiple speakers) and you would in all probability hear them as separate.
 
#9 ·
Randy I am in a similar situation but with fewer locomotives. I think others have said impedance and power output are considerations.

Tom's Shoe String Solution. I am battery powered with battery in a trailing car. I have a mix of Revo and old TE. I like the Dallee Alco diesel sound. EMD is okay, not as good as Alco. I did not care for old steam sound but I understand new cards are improved.

1. Steam. a) I have one Revo card with steam sound. It is in a trailing battery car but I run a second set of MU wires to the speaker in the tender. I can use this sound card with several different engines, but just run only 1 at a time.
b) I have an older Pheonix sound card in a separate box car. A sound car if you will. ( I bought it 2nd hand) Again I can swap it around between steam engines.

2. Diesel. Some of my diesels have Dallee sound cards. I run a battery car with Revo or TE behind the diesel.(Sound cards are in locomotive) If I have a 3 diesel lash up, I find that all 3 diesels cranking out sound is just too much noise. I personally think that it sounds better with 2 out of 3 with sound cards. So you might consider only doing 1/2 or so of your units. I place the non sound unit in the middle.

Just another way to do things. Let us know how you proceed.
 
#12 ·
Hey Randy- This is from the Dallee site. Hope it helps....


A second speaker, wired in series with the main speaker, can also enhance sound quality and will permit a higher volume without damage to the individual speakers. A tube with a speaker at each end or a speaker in a doorway at each end of a body shell is an excellent approach. A four speaker approach will yield the highest volume while still maintaining the 8 ohm minimum requirement. Drawings for this are included in the speaker instructions.


http://www.dallee.com/PDFs/DCV3-DIESEL-AUTOH-R9.pdf

http://www.dallee.com/PDFs/SpkrWrgSrsParallel.pdf


-Kevin.
 
#15 ·
Actually, volume is much more related to speaker efficiency, which can vary a lot. Quality speakers will have that rating in their specifications.

Remember that doubling the power to a speaker only results in a 3db increase in volume...

So, in most cases there is little to gain by going to 4 ohms over 8.

A proper enclosure will increase the apparent volume by adding more mid and lower frequencies. High frequencies are unaffected.

Greg
 
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