GP7 sound install

[bapguy]

I have photo's of my sound install in a Bachmann GP7 but can't get them to post here. I did get them posted on the Model Railroad Hobbyist Magazine site(mrhmag.com). They are in their posts index section. Joe

[richg]

I have photo's of my sound install in a Bachmann GP7 but can't get them to post here. I did get them posted on the Model Railroad Hobbyist Magazine site(mrhmag.com). They are in their posts index section. Joe

Many here use photo Bucket to post photos and You Tube to post videos.

Rich

[bapguy]

I have photo bucket but can't get it to work here. Any help you can give would be great. Joe

[richg]

Click on IMG code in Photo Bucket. You might have to click twice. I have to. I then paste into the forum message. I have a browser open to the Bachmann forum and another browser for Photo Bucket. Don't ever move the photo in Photo Bucket or the photo in any forum will go away.

Look at the below photo. You can see the four options.



Rich

[bapguy]

I put a piece of plastic under the deoder to prevent a short. Decoder Soundtraxx # 828020 speaker # 810054:1" diameter.  Joe

[richg]

Very nice Joe. Looks like the stay alive cap come smounted on the decoder board now. All mine had the cap hanging off a six inch long pair of wires.
Some may wonder, how much did you mill off and did you make the slot for the cap?

Rich

[bapguy]

Since this is 1st gen. diesel, I use decoder # 828020. This is for a Bowser F unit, but has the keep alive caps built into the board. After I removed the PC board and LED holders, I looked at the top of the frame and decided where to mount the decoder. I had to grind off one of the mounting tabs for the old decoder. I then placed the new decoder upside down on the frame. I drew a line on the side of the frame where the front and back side of the caps where. I then drew a line on top of the frams connecting the side marks. This is the area I needed to remove. I filled in the area with a black marker. I then put the frame in a vice. To mill out the area, I scraoed a line down the center of the frame where the black mark was. I drilled a hole in the center of each side of the frame. I started with a medium small drill bit. Once the hole was drilled, I user a larger bit to open it up, then a bit that was slightly smaller than the diameter of the cap. This way you won't ruin the frame. When the holes drilled, I took my motor tool with a  reinforced cut off disc and made the holes into the slot pictured. I test fitted the decoder  to make sure it fit. I cleaned up the frame on the sides and top with a file. Remember to ware a mask and eye protection as there's a lot of metal particles coming off the frame.   Joe   

[Joe Baldwin]

I'm doing an install on the GP9, so I assume things are the same. (risky to assume I know)

Joe you specify a 1.0 speaker which is actually 1.1 (according to Soundtraxx and other sources).  I am assuming you mounted it in the belly which is milled for a speaker (on the GP9 anyway).  Two questions:

1 - How did you get the larger speaker to fit in the belly hole  GP9 is 1.08
2 - What did you do for a baffle?

Thanks

Joe

[richg]

Many are not aware most small speakers come from across the Pond where Metric is used and are not aware a one inch speaker, 28mm, is actually, 1.10236 inches.

With DCC today, you cannot assume about anything.

I would use an appropriate router bit in a Dremel. I have done something similar in the past.

I keep a Calculator site in Bookmarks for quick conversions.

Rich

[bapguy]

I diasembles the frame top to mill it out. I then removed the trucks and motor. I took a cut off disc in my motor tool and enlarged the hole. Bachmann states a 1" speaker will fit but I had to enlarge the hole. The loco comes with a baffle to go on the back of the speaker, but I couldn't get it to work, so I put electrical tape over the rear of the speaker. I also drilled out the dimples in the fuel tank cover. This made a big difference in sound.  Joe

[richg]

Make sure to put a grill in place between the tank bottom and speaker. Some have found the magnet is capable of picking up magnetic material from the roadbed and it affects the speaker after a while.
A piece of women's nylon stockings or coffee filter material works.

Rich

[rogertra]

Make sure to put a grill in place between the tank bottom and speaker. Some have found the magnet is capable of picking up magnetic material from the roadbed and it affects the speaker after a while.
A piece of women's nylon stockings or coffee filter material works.

Rich

Rich.

Excellent idea.

[Joe Baldwin]

Thanks Joe for your reply, which was exactly what I anticipated.  

As you stated, SoundTraxx and some other speaker vendors claim a 1.1 inch (28MM)  speaker is one inch however QSI also makes a 1 inch round speaker that is actually 1.0 inch  (26MM) and it fits the Bachmann Speaker receptacle perfectly.

Like you, I will be fabricating some kind of baffle out of tape or RTV.  When I picked up the speaker this morning at my LHS (http://www.caboosehobbies.com) Roger, one of their DCC tech reminded me of putting some kind of cloth over the speaker however, I am thinking that drilling out the Bachman grill holes with the appropriate small drill will be more effective than cloth.  I can always retrofit with cloth/hose if needed.

[bapguy]

When you get done, go to the Model Railroader web site. They have a forum but I can't remember if any one can get into it. If you can, under DCC look for a post about low sound level in a Athearn GP9. One of the resposes is a list of CV's and the values for the equaliser in the Tsunami decoder. I changed the setting and it makes a big difference.  Joe

[Doneldon]

As you stated, SoundTraxx and some other speaker vendors claim a 1.1 inch (28MM)  speaker is one inch however QSI also makes a 1 inch round speaker that is actually 1.0 inch  (26MM) and it fits the Bachmann Speaker receptacle perfectly.

Joe-

This irritates me no end. Soundtrax knows very well that an inch is 2.54 mm. Why they try to
peddle their 28 mm speakers which won't fit a one-inch space as fitting is just wrong. I suppose
they figure some folks have enough fudge factor room to get them in but I still think this is
downright dishonest.
                                       -- D