Putting sound in a P2000 GP-9 (Finished)

[scubaterry]

The July issue of Railroad Model Craftsman had an article on putting sound in a Proto 2000 GP-7 that made it seem so easy. I have two P2000 GP-9's I just bought and several Soundtrak sound modules laying around so I decided to give it a try. With the trusty dremel and many cut off disks I was able to remove a small section of the weight in the nose section just as the article described. To my surprise it was easy and I managed to get in a 1 1/2 by 3/4 inch oval speaker. Just a tad bigger than the one used in the article. As I slid the shell over the weight I noticed that I had some room above the speaker below the curved section of the cab. I removed the shell and placed a 3/4 soundtrax speaker w/enclosure ontop of the oval speaker and tried the shell again. FIt perfect. So now I have a two speaker set up that should sound great once finished. I know soundtrax rec that you don't use multiple speakers on this module (AT100LC) I have had it wired up to two one inch speakers in a boxcar previous and it sounded fine. I have digital pics of the process and am in the process of starting up a photo web page. When I have the pics published I will post them. The reason I am posting this is when I first read the article I was saying to myself "wow that would be great to get sound in my GP-9's" but I figured it was to advanced for me. Well once I got into it I found it to be very straight forward, easy and fun.
Terry

[Texas Zepher]

QUOTE: Originally posted by scubaterry

So now I have a two speaker set up that should sound great once finished. I know soundtrax rec that you don't use multiple speakers on this module (AT100LC) I have had it wired up to two one inch speakers in a boxcar previous and it sounded fine.

Terry,
I don't see where they don't recommend multiple speakers. I am not familiar with the ATxxxLC, but I know the higher priced full DSX and DSD (LC = low cost) are designed to handle two.

But, if Soundtraxx doesn't recommend using multiple speakers it is for a reason. Just because it sounds fine now doesn't mean you won't end up burning it out. Did you wire the speakers in parallel or series? If they are 8 ohm speakers and you put them in parallel the sound processor is only loaded with 4 ohms. It could fry quite quickly. If you put them in parallel then you have 16 ohms on the sound processor which is generally better, but can cause other problems like over heating from over driving the amp.

[scubaterry]

Texas Z
actually the decoder is a DSD-AT100LC. For Athearn Loco's. I bought it several years ago then bought P2000 Loco's. I put it in a boxcar about 18 months ago. Speakers in parallel. Not sure of the resistance. Probably 8 ohms as I bought it fm Soundtrax. The only place I see it rec one speaker is on the installation sheet that came with the decoder...Note: Multiple speaker installations are not rec for use with the DSD-AT100LC. So far no problem with it like I say about 18 months on it. Hey if it fries it fries. Maybe someday the Tsunami (sp) will be out and I can upgrade. The point of the post was to illustrate how easy of a modification it was to upgrade a loco to sound. I should have it cranking by the weekend and I will post results. Thanks for your info.
Terry

[dave9999]

Hey Terry,
I have thought of installing sound in my P2K GP7 but also thought it would
be rather difficult. I would like to see your photos when you get them online.

I will check out the MRR article as well. Dave

BTW. Me and the "other" Dave (Trains by Johnson)were talking about you the other day.
Were your ears burning?[:D]

[scubaterry]

Dave good to hear from you again. Say heh to Dave next time you talk. I emailed him at his HS and never got an answer. Actually Dave the article was in Railroad Model Craftsman mag, July issue not MRR. I hope I haven't commited a phu-pah referring to another mag on this forum. If there were ten RR mags on the market I would have all ten and MRR would no doubt be the best of the bunch (there that aught to take care of it). I will try to get up pics of my project and my layout progress as soon as I can. Side note: Wife and I went Kayaking in our backyard today and a 6-7 ft Snook rolled up and darned near bumped our kayak. Scared the crap out of both of us. Saw a 300 lb sea turtle yesterday.
Terry
basking in the Florida Keys

[AntonioFP45]

I have the RMC issue.

Excellent article! I will be using it as reference as I convert my P2K GP9 to DCC sound.

Nothing wrong with mentioning a competing magazine on here. IT'S ALL ABOUT TRAINS!

So, share and enjoy!

Take care.

[scubaterry]

Antonio let me know how yours turns out. I was able to use a little bit bigger oval speaker by taking out a little bit more of the forward part of the nose section. Bigger is better I'm thinking. Should have it online this weekend.
Terry

[scubaterry]

Forgive me if this does not work it is my first try at posting pics. This pic (if successful) shows the oval spkr in place and the section that was removed. I have several more pics showing the process I will post if this is going to work.

Let me know if pic shows up. Thanks
Terry

[AntonioFP45]

ScubaTerry,

Cool shot!

Could you please tell us the size of this speaker as well as the brand name or part number? I totally agree with you in that the bigger the speaker, the better!

Looks like you're going to have one sweet sounding unit.

High Greens to you.

[scubaterry]

Antonio
Sorry for the deley. Been gooding off. I bought all of my speakers from gadgettoms.com. The one I used in the pic was a 1 1/2 x 3/4. Metal frame (had to file small amount off both long sides to fit). Give me a day or so and I will check the site out and give you a part #. I have since decided to go with only the oval and hold off on the rd 3/4 second speaker until I hear what it sounds like. Should have it on the tracks late tonight and will let you know. If you have broadband I can send you a short vid clip of the loco w/sound.
Terry

[scubaterry]

Antonio
I checked Gagettom.com and the speaker in question is not in stock. Loystoys has it in stock. item # LS-SO. 1.56 by .78. I can't tell for certain if it is the exact one, however the size is the same as mine. The one I have has a metal backing to it with only two very small cresents of opening so enclosing it was a breeze. I just glued a small piece of cardboard over each cresent. I will give that a shot and if the sound is not loud enough I may have to put in a slightly larger enclosure. I have read some people say to make the enclosure as small as possilbe others say 1 1/2 times the area of the speaker baffle??? DOn't know will have to play it by ear literally.
Terry

[Texas Zepher]

QUOTE: Originally posted by scubaterry
The one I have has a metal backing to it with only two very small cresents of opening so enclosing it was a breeze. I just glued a small piece of cardboard over each cresent. I will give that a shot and if the sound is not loud enough I may have to put in a slightly larger enclosure.

Yes, that is going to create too much pressure when the speaker "cone" tries to move. It won't only effect the loudness but also the lower tonal quality.

QUOTE:
I have read some people say to make the enclosure as small as possilbe others say 1 1/2 times the area of the speaker baffle??? DOn't know will have to play it by ear literally.

Hmmm, I would have said as large as possible with 1 1/2 times being the absolute smallest.

Your "playing it by ear is the best". There will be natural harmonics and resonance created with the specific sounds and the interaction of the shape and size of the speaker(s). For round speakers I mount them in one end of a pipe. I insert a pipe of slightly smaller diameter into the other end. I cap the exposed end of the 2nd pipe. Then I slide the pipe in and out until I find the right "size" for that speaker. Unfortunately I found that a Sountraxx 1st Generation Diesel w Nathan 3 horn sounds really greate with a 1 1/4 pipe 16" long. I get some really deep throaty engine sounds. Obviously I can't mount that in any HO locomotive. I ended up with it being about 4" long just right for a dummy B unit.

It is also often desireable to put some foam or other sound deadening material into the enclosure to prevent internal echos and "booming".

[scubaterry]

TexasZ
Well as it turns out I broke one of the internal wires on the speaker. I ordered several more from Loys Toys along with sheet lead for making an enclosure. So I will agree with you that you need some space in the enclosure for the speaker to sound good. I did wire up a one inch speaker w/enclosure just to check out the wiring etc and it sounded pretty darned good even with the shell off so I have high hopes this will eventually work out. My next project will be to try to get sound in my two GP-30's more difficult as there is much less room for speakers.
You mentioned foam in the enclosure...Would you pack the enclosure tightly or just loosly?
Thanks for your info and interest.
Terry

[Texas Zepher]

QUOTE: Originally posted by scubaterry
My next project will be to try to get sound in my two GP-30's more difficult as there is much less room for speakers.

See if you can find a way to mount them diagonally, one can usually fit a larger speaker that way.

QUOTE:
You mentioned foam in the enclosure...Would you pack the enclosure tightly or just loosly?

I have never packed the enclosure but simply put foam over any surface that might reflect sound. For certain one doesn't want the foam to shift around. Say 1/4" thick cut to the right shape and glued onto the surface it is shielding. On my "PVC pipe" enclosures this would just be a circle of foam against the sealed end. For a while I used 1/8" foam with peel-off self-adhesive on one side. It was great, but I can't find any more.

It might not be a bad idea to pack it. Several of my high end stereo speakers are packed and pretty tightly too. Research needed.

[rexhea]

Terry/TexasZ
Thanks for all this info. I have a P2K GP7 that not only was my first loco, but it is also one of my best runners. With sound in most everything else that I have, I would like to install sound in it. I will see if I can get a copy of that Mag.

REX [:)]

[AntonioFP45]

Terry,

Thank you very much for the info on the speaker.

Texas Zephyr,

forgive me but I little confused about the "pipes" that you fabricated for your speaker. Do you have a picture?

It will still be a while longer before I install sound in my Geeps or cab engines as I'm still tweaking some of them, and replacing motors on two of them.

High Greens

[scubaterry]

Well my little project is finished. Sorry no pics as I was so thrilled to finish and get it together I forgot. But it went together pretty much as intended as shown in the pic above. I ended up putting the capacitor on top of the speaker enclosure nestled into the recess provided by the curve in the cab roof. It fit perfectly. As a result had no room for an enclosure so I taped the speaker tight to the frame and in the process just covered up the speaker holes with the tape. I put the shell on and tried it on the track with and without the taped holes and it made a pronounced difference. With the taped holes it sounds loud enough that I had to tone it down a bit. I also have a P2000 GP-9 w/QSI sound that I compared it to. The QSI (with 2 one inch speakers) sounds very tinney especially the horn. The home grown job sounds much more satisfying. I have a short Video of it but not sure how to post it? Something about doing a job yourself that gives you a great feeling. This may become my favorite Loco. Thanks for all the input I got from this thread. Believe me If I can do this anyone can. Now its on to my two GP-30's.
Terry

[Texas Zepher]

QUOTE: Originally posted by AntonioFP45
forgive me but I little confused about the "pipes" that you fabricated for your speaker. Do you have a picture?

Unfortunately all the ones I had made have been painted black and I can't get them to photograph at all. BUT here are some parts that give the general idea.

Unassembled parts excluding the cap for the end of the pipe opposite the speaker. This is actually a coupling and a pipe but any two pipes that fit into one another could be used. I use the really thick couplings to be certain there is no vibration. Vibrations are bad for speaker enclosures.


Assembled - a tube of any length (limited by interior locomotive size) can be added to the coupling to match the characteristics of the speaker and sound unit. Note that the speaker magnet is inside of the pipe, so one must make allowance to get the wires through the tube. The size makes this design suitable only for dummy units.

The bigger the pipe the harder it is to fit. I often have to cut the pipe down to size. I originally tried filing or grinding them down, but it took forever. Now I start with the band saw and then just file it smooth. This one is cut to exactly fit into an HO "FB" shell.

I have gotten more complements on the sound from this configuration than any other HO sound units I own. I've also been experimenting with elbows, Ts, and multiple speakers to try to get richer low freqencies. I have also just found a source for some really big high quality computer speakers that are exactly the right width for HO FB shells. These promise to make my quest for low frequency even easier. The only bad thing is that they are oval......

[NeO6874]

I have also just found a source for some really big high quality computer speakers that are exactly the right width for HO FB shells. These promise to make my quest for low frequency even easier. The only bad thing is that they are oval......

I don't know if they sell direct to consumers, but the Harmon/Kardon makes some really good speakers for laptops.  I've seen them mainly in Toshiba Satellites - they're maybe 1" or so in diamerer, and maybe 3/4" long - they're as deep as the laptop shell allows.  I'm no audiophile, but they sound really good for music - and they generally have pretty good bass as well.....

[Anonymous]

Try putting two speakers back to back in your PVC pipe. Then drill a small hole in the side for the wires to come out, and seal the hole with any kind of glue.

I've used two speakers with Soundtraxx decoders in many installations. I have several FA,FB, and F7 A and B consists with a speaker in each unit. I use the Miniatronics miniature connectors, and just put another speaker in the B unit. The miniature connectors allow you to separate the two units for service.

[ShawneeHawk]

Are you sure the article was in the July 07 issue of RMC?  Because I backordered it, it arrived today, and the wife said there was absolutley nothing in that issue about installing sound in a P2K.  I really need this article, as I have several GP 7's to convert.  Thanks.

[kansaspacific1]

ShawneeHawk:  Try RMC for July 2005.

Chuck

[ShawneeHawk]

Well duh....I should have checked out the date when that thread started!  Thanks for pointing that out, Chuck.