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Speakers and DCC

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Speakers and DCC
Posted by espee8110 on Wednesday, May 25, 2011 12:52 PM

Howdy all!

I looking into the idea of adding a high bass speaker to a locomotive since the current one is quiet in comparison to other locomtives down at the club.  In entertaining that idea, I came up with some alternatives.  One I have a question about that I have not been able to answer.  I am planning on putting the HB speaker in a dummy locomotive and connecting it to the decoder through wires passing near the couplers.  The problem is that if I operate the powered locomotive by itself, I do not want to have to go through the process of connecting the speaker wires back to the origional speaker.  So the question is, can I operate the speakers together on the same circuit and decoder?  Or do I need to get another decoder for the HB speaker? 

For reference, the powered loco is an HO Bachmann GP7 with factory decoder, the sound decoder is a Digitrax SFX0416 decoder being used for sound, with the original speaker, and the planned HB speaker is a Tsunami Soundtraxx Mega Bass Speaker, part number 810130.

Any help and advice is greatly appreciated!

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by maxman on Wednesday, May 25, 2011 2:45 PM

Assuming that the SFX04 has the capability, I believe that you could operate both speakers from the same decoder.  But the speakers would need to be wired either in series or parallel (before you did this you'd need to determine which is correct).  But this would mean that you'd have wires going between the two units with some sort of mini-connector in between. (thinking about this, the speakers would need to be connected in parallel.  If they have to be connected in series, then there is no way that you can remove the second speaker without breaking the circuit.  Again, before you do this, check which connection method is correct).

If it we're me, I think I'd just get another sound only decoder for the second unit.  That way it would have its own address, which would then allow you to consist it with some other engine you own.

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Posted by espee8110 on Wednesday, May 25, 2011 3:00 PM

Thank you for the advice.  Any idea where to look to find which way is correct?  I checked through the manual about this earlier and didn't find anything.

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by maxman on Wednesday, May 25, 2011 5:39 PM

espee8110

Thank you for the advice.  Any idea where to look to find which way is correct?  I checked through the manual about this earlier and didn't find anything.

Concerning the speaker installation, take a look at page 24 (Installation) at the following site: http://www.soundtraxx.com/manuals/tsuinstallation.pdf.  Even though this is a Tsunami decoder installation, the speaker info and wiring diagram should apply to anything.  It shows a two speaker and a four speaker installation.  It explains things better than I could.

For the two speaker installation, it shows the speakers in series.

If your question is can the decoder you have actually power two speakers, that I can't answer.  Probably some one else will answer that here shortly.  If not, you can ask that as a separate question.

Regards

 

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Posted by richg1998 on Wednesday, May 25, 2011 5:41 PM

Look at the documents at the Soundtraxx site. Those documents show the proper way.

http://www.soundtraxx.com/

The below fellow has a lot of good sound decoder info also.

://www.mrdccu.com/

Store the links in Favorites. You will need them.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by rrinker on Wednesday, May 25, 2011 8:40 PM

 You need to knwo what the decoder can handle as far as speaker impedence. Two 16 ohm speakers in parallel is 8 ohms - so if the decoder can handle 8 ohms, then you cna just wire the plug in parallel with the existing speaker, when the dummy is connected, you have a pair of speakers and a total impedence of 8 ohms. When disconnected, you have the single speaker operating at 16 ohms. ANother option is to use a 4 pin connector and cut one of the wires to the existing speaker. The line from the decoder would go to pin 1, the wire to the internal speaker would go to pin 4. When the dummy is plugged in, it gets speaker power through the middle 2 pins. When the powered unit runs by itself, a plug with a wire connecting pins 1 and 4 is attached and just the internal speaker works.  No issues with series/parallel and impedence that way, only 1 speaker at a time works. In a dummy you cna probably fit a LARGE speaker, or 2 or 3 of them. A physically large spekaer is probably better than the high bass speaker. Or you could get fancy and put a large speaker in the main body shell and a cmall one under a radiator fan with a capacitor to filter out the lows - basically makign a 2-way speaker system for more overall frequency respone range.

 If the dummy has metal wheels consider adding power pickups and using a larger connector to you can parallel the track pickup as well as the speaker.

            --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by MisterBeasley on Thursday, May 26, 2011 6:41 AM

The problem isn't the speaker, it's the SFX0416.  These decoders have very low output level.  Even cranked up all the way, they are hard to even hear over other sound locomotives, or even non-sound locomotives if they growl a bit.

Get an SFX004 Soundbug instead.  The Soundbug does not have function outputs, so if you're using the SFX0416 for lights you will need to make other arrangements.

It takes an iron man to play with a toy iron horse. 

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Posted by espee8110 on Thursday, May 26, 2011 7:20 AM

Randy: That is a good idea, but a bit complicated for my tastes Smile  I will still look into it to see if I can put that together.  My dummy does have metal wheels (it is an old working engine that lost several motor parts during an accident) so I may just make it a second power connector.

Mister: Fortunately I am not using any of the outputs.  However, the SFX004 is difficult to make work with my loco.  I was reading the manual and it mentions standalone service.  If I put this decoder in a dummy with a bigger/deeper speaker and hooked on to the old track power leads from the loco, do you think that would work? 

From what I understand, doing this and programming all of the decoders to the same address makes them work in conjunction.  I do not plan on having the dummy in use without the primary loco.

Essentially, I am looking for something simple.  I am not the best with electronics.  I can solder, but I also once used my body to connect 14 car batteries Embarrassed

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by espee8110 on Thursday, May 26, 2011 7:25 AM

richg1998

Look at the documents at the Soundtraxx site. Those documents show the proper way.

http://www.soundtraxx.com/

The below fellow has a lot of good sound decoder info also.

://www.mrdccu.com/

Store the links in Favorites. You will need them.

Rich

Thanks for the info!  It actually answers a lot of questions.

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by MisterBeasley on Thursday, May 26, 2011 7:51 AM

The SFX004 Soundbug is designed to work with their 165-series decoders, but it will work with any decoder.  Instead of a convenient plug-in, you would need to wire it in to power.  Like the SFX0416, it needs to be programmed separately from the engine decoder.

I have one installed in an Athearn F7A.  I think I used a Digitrax DH-123 decoder to run the engine.  I put an SFX0416 into a dummy F7A, which I consist with the powered one.  With this combination, I've got two sound units, and I can use the SFX0416 to drive the headlight of the dummy unit when I run the consist with the dummy leading.  The powered unit with the Soundbug dominates the audio level of the consist, though.

It takes an iron man to play with a toy iron horse. 

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Posted by rrinker on Thursday, May 26, 2011 9:04 AM

 The SOundbug plus as big a speaker you cna fit int he dummy would be a great way to do things. I have a Stewart F7 B unit dummy that I put an old Soundtraxx LC decoder in, with big speaker. The old LC decoders have REALLY bad motor contorl, not even silent drive to some brands of motors buzz horribly, so I just ignored the motor drive. I couple this up with any other F unit and MU the address and - instant sound with any F units I want.

 All you need for the soundbug is to hook the two large screw holes to the left and right rail pickups, and connect a speaker. Tape over the 8 pins so they don't short on the frame anywhere, and you're in business.

                      --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by espee8110 on Thursday, May 26, 2011 12:41 PM

Okay, so I have been looking around and using y'alls advice to see what can be done.  Unfortuantely, I can not find an answer to my question on either Soundtraxx or Digitrax sites.  From the Digitrax site it says that the speaker on the SoundBug SFX004 is a 32 Ohm.  While I understand almost all of DC power, the AC of DCC boggles me.  So, at the possiblity of showing how little I understnad,  if I were to get one of the speakers I am looking at, both of which have and impedence of 8 Ohms, can I still use them with the SoundBug decoder or do they not offer enough impedence? 

Basically what I am hoping is that this means the decoder can support up to 32 Ohms, not requires 32 Ohms or more.

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by fwright on Thursday, May 26, 2011 1:11 PM

espee8110

Basically what I am hoping is that this means the decoder can support up to 32 Ohms, not requires 32 Ohms or more.

Unfortunately, facts go against your hopes.  If a amplifier is rated for 32 ohm speakers, you can use speakers of 32 ohms or more.  Speakers having less impedance than the amplifier is rated for draw too much current and cause the amplifier to overheat.  As some point, the excess current will let the magic smoke out.

In this case, speakers with a 100 ohm rating will not damage the amplifier, however the maximum sound volume produced may be too low to suit.  Best to stay at or slightly above the amplifier rating for speaker impedance.

Fred W

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Posted by MisterBeasley on Thursday, May 26, 2011 2:00 PM

It's been a while, but my recollection is that both the SFX004 and the SFX0416 came with 8 ohm speakers.  This is in direct contradiction to the documentation on the Digitrax site.

It takes an iron man to play with a toy iron horse. 

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Posted by yankee flyer on Thursday, May 26, 2011 4:12 PM

Oh, the heart break of using sound in small model trains.
I visited the Tsunami site and sampled the sound of the TSU 1000. It was heart warming to hear that big EMD 645 rumble to life. But when I hooked it up and connected it to the only oval speaker that would fit in my GP40 it sounded like scratching your nails on a blackboard.
It's a shame I can't use 8" speakers with a sub woofer like the computer uses.   Grumpy  Whistling

Have fun

Lee

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Posted by rrinker on Thursday, May 26, 2011 10:05 PM

The SFX004 SOundBug definitely has an 8 ohm speaker. I don't think the 0416 does. I can provide a picture of my SOundBug with the stock factory speaker still attached to prove it's labeled 8 ohm.

                   --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by espee8110 on Saturday, May 28, 2011 12:08 AM

Okay so I spent some time going through the various guides and manuals and the Sound Bug can take any 8 ohm speaker.  I know the SFX0416 does have an 8 ohm as I have that one installed currently.  I would upgrade its speaker if I had the room...  I think for now what I am going to do is get a Sound Bug, hook it up to the power leads of the old engine, and put in a large speaker and a high bass speaker.  Maybe that can prevent that nails on a black board sound Lee Smile  It looks cheaper than looking for a whole new engine with DCC and sound.  From a few sites I total 40 for the decoder + 10 for each speaker to be about $60.  And as long as they are wired properly, they can work off of the same decoder, one for loud, one for depth.  Opinions or thoughts/experiences?  From what I can tell the F7 shell has enough room with the motor removed.  And thanks for the clarification Fred! 

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by MisterBeasley on Saturday, May 28, 2011 10:00 AM

If you don't mind taking the shell off twice, I would seriously suggest that you replace just the decoder.  The output power of the SoundBug is so much better that your existing speakers may be enough to do the job.

Do you have a proper enclosure for the speakers?  I don't think we discussed that.  If you're using an unenclosed speaker, you're never going to get its full potential.

It takes an iron man to play with a toy iron horse. 

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Posted by espee8110 on Saturday, May 28, 2011 10:43 AM

I do have a good enclosure, from what I'm told.  A directional plastic baffle with a backing, and several holes in the underside of the fuel tank for the sound to escape.  From what I understand Digitrax is known for having quiet sound speakers.  I listened to mine outside of the shell next to generic Soundtraxx speaker of the same size and it was drowning mine out...

Chessie HO and SP N in College
http://collegerailroad.blogspot.com/ 

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Posted by MisterBeasley on Saturday, May 28, 2011 2:06 PM

espee8110

I listened to mine outside of the shell next to generic Soundtraxx speaker of the same size and it was drowning mine out...

Again, if you were using the SFX0416, it's not a fair comparison.

It takes an iron man to play with a toy iron horse. 

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Posted by hobo9941 on Wednesday, June 1, 2011 10:26 PM

You could use another sound decoder with the same address feeding into the computer speakers and sub woofer under the layout.Whistling

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