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Fitting sound to Bachmann 3F & 4F


Ray H
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Apologies of this has been covered before but my searches couldn't find it.

 

I have just purchased sound decoders from Howes for the Bachmann 3F 0-6-0 and the Bachmann 4F 0-6-0. These are the first sound decoders that I have bought.

 

I'd previously raided the 3F for the supplied non-sound 21 pin decoder to fit to another loco that won't have sound - at least for the time being. Therefore, with the loco still separated from the tender, I decided to fit the sound decoder to the 3F first.

 

I had the body off the tender but hadn't removed the weight. I had however previously noticed that there were already holes in the floor of the tender, presumably to fit the speaker over. I therefore assumed that fitting the speaker was a quick job. It doesn't appear to be unless I'm missing the obvious.

 

I've just removed the weight and find that the wheel arches will prevent the supplied speaker from sitting flat on the tender floor.

 

I can envisage at least a couple of ways of fitting the speaker. One is to drill suitable size holes in the weight for the sound to pass through and then fix the speaker to the weight. The other is to ditch the weight and build up the floor around the wheel arches in such a way that the rim of the speaker is fully supported/enclosed and the only exit for the sound is through the holes on the floor. I suppose buying a different size/shape speaker is another idea.

 

Is anyone who has fitted sound to the 3F using the Howes kit able to point me in the most appropriate direction to proceed.

 

I've just had a glance at the 4F - which was put back in its box after it had been run in and is still there because I didn't have a decoder for it. That doesn't even have holes in the floor so speaker fitting suggestions for that loco would be even more welcome.

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Without knowing these two locos but as a generic thing, It is just as good to use the speaker facing up, make the holes in the fake coal and stick some real coal over the holes.

 

Although down facing speakers can increase volume and bass, remember that your listening angle is always above the loco.

 

There is no substitute for fitting a speaker under a drilled through chimney if possible.

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Do Bachmann supply a speaker enclosure with these locos?

 

The dimensions of that might give you a clue as to what size speaker they expect you to install

 

Kind regards

 

Phil

 

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There is a non-descript (as far as I can tell) oval shaped piece of plastic with the 3F that could possibly be something for a speaker to sit on albeit that the round (slight) recess in the centre (which could be where the front of the speaker drops into) is only about 15mm in diameter.

 

I think that I'll use the supplied piece of plastic as a template to make a plasticard mount for the Howes speaker which is 23mm in diameter. Will it matter that the speaker rim is not flat on the floor?

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Hi,

 

I think when i did a couple i swapped the 23mm speaker for one of the 16 x 25mm ones and mounted it under the coal load after drilling some holes in it and then built up some coal on top using larger lumps to enable the sound to escape.

 

Cheers

Simon

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post-10059-0-86494200-1388829539.jpg

 

This is what I've done as a first attempt.

 

The plate at bottom left is the smaller weight found inside the tender when the body was removed. It (currently) won't be going back.

 

The plastic at bottom right is what I presume is the nearest thing to a speaker housing that Phil mentioned above. The lower front edge (and the opposite side which can't be seen in the picture) have been attacked by me to see if I rest the Howes speaker on the wheel arches and use the plastic to hold it in place. I wasn't impressed with the result.

 

Instead I used the size of the metal weight to cut a piece of plasticard that I then cut a 20mm diameter hole in (and drilled a couple of fixing holes in as well). I then placed the Howes speaker over the hole and fixed the enclosure that Howes supplied to the plasticard, holding the speaker in place.

 

I've loosely placed the tender body over the chassis and that still seems to fit. I'm about to re-unite tender with loco to try out the decoder. I'll then refit the tender body when I'm reasonably happy that I won't need to get at speaker or decoder again.

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What you've done Ray should be OK.   A bit of sealing around the bottom of the speaker cylinder to the plasicard would complete it, either bluetac/whitetac, or bathroom sealant.  Sealing things makes a big difference to speaker performance. 

 

However, the tender looks like another I've done recently,   The rectangle of plastic you've used looks like it is approx. 20x40, ie. exactly the size of a typical rectangular speaker.   I think the underframe of the tender has been designed with those rectangular speakers in mind, so for future installations you might want to use a different speaker shape.   

With the bigger speaker, seal it to the bottom of the tender chassis (so no air leaks), and ensure the tender body is a very snug fit.  This makes the entire tender into the speaker chamber.   I also threw away the 21-pin connector, and hard-wired the decoder onto the four wires which come through the base of the tender.  I then used the spare space created for a TCS KA1 stay-alive module attached to the sound decoder.

 

 

-  Nigel

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Nigel

 

Thanks for the further info. I did wonder about "sealing" the area between the underside of the plasticard and the top side of the tender floor. Is that what you're suggesting or are you suggesting running a micro bead of sealant around the edge of the speaker enclosure on the top side of the plasticard?

 

For others, the 4F has received the same kind of treatment and both tenders have been re-united with their respective bodies and run round the layout (more than once). I'm well impressed.

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I would seal both Ray - the more enclosed the sound path and the more robustly the speaker is mounted the better your sound reproduction will be.

 

The speaker as supplied with the Loksound chip is perfectly capable of excellent sound if well mounted

 

I suspect your plastic oval is the Bachmann speaker mount - difficult to see but looks as if the central well is intended to accommodate the speaker driver coils (the raised area on the back of the speaker)

 

Look forwards to hearing the result!

 

Cheers

 

Phil

 

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I admit to being a bit sceptical that I'd notice any difference having sealed the speaker as suggested but I was pleasantly surprised having done so. It was well worth the effort.

 

Thanks to Nigel & Phil for suggesting it.

 

Now which loco (or DMU) do I fit sound to next?

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Its the clear separation of the sound from the front and rear of the speaker that makes the difference - prevents destructive interference between the two sets of sound waves which would give reduced volume and quality.

 

What else have you got to chip?

Phil

Edited by Phil Bullock
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The rest of the motive power comprises:

 

Ivatt 2-6-2T, 2-6-4T, 2-6-0, 0-6-0T (Jinty), 0-4-0T (Pug)*, 0-4-0T (Y1)*

Class 105, 108, 153*, Derby Lightweight.

Class 08, 15, 16, 25, (Airfix) Class 31, 37, 47

 

* - The Pug & Y1 possibly won't stay and the 153 is only here because I think the single vehicle LM livery is really impressive. It'll probably see little use, at least on the present layout. I'm undecided about the Class 31: I want one on the layout but it has to be in green, without the yellow panel and must have a roof mounted train reporting number box.

 

The Bachmann 1F and Class 101 are on the to-buy list when they're released.

 

It was more a rhetorical question, partly based on ease of fitment and not breaking the bank completely!

 

(Oh, and I've got to finish (start?) building the layout and building/fitting the signals, which may include the purchase of a twenty lever ground frame, he says, talking about costs! At least the track is down so that's one expense that I've not got to consider.).

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I have to wonder why when manufacturers go to the trouble of making holes in the tender and supplying an enclosure they don't suggest in the instructions what speaker will fit. I fully accept that folks might not want to follow their suggestion but they must have had a particular one in mind when they mould the enclosure.

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Ray

 

I don't have experience of them but I guess any of the tank locos are not going to be the easiest to fit sound to!

 

For the diesels it will depend on make and how recently they were manufactured

 

Have a look at

 from 3.30 to 8 mins for a 25, 37 and 47 from Howes

 

The current Bachmann versions of these have speaker recesses for a bass enhanced/reflex oval speaker in the chassis block under the cooling fan - for the older ones its a case of finding a location for the standard round speaker that the chip comes with.

 

Cheers

 

Phil

 

 

 


 

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  • 2 weeks later...
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Phil

 

Thanks for that link. I really must spend some time and look at your layout thread in full.

 

My Class 25 was new a year or so ago. The class 37 & 47 locos were second hand but had plug in sockets so hopefully aren't that old and with a bit of work should be able to accommodate a speaker - I've had both bodies off to fit the decoders but can't recall how much room there was for the speaker. I also want to fit lights to the Class 37.

 

The Class 31 is a doddle space wise although I'm still undecided about the long term future of the loco given its vintage, but at £150ish for the latest Hornby, the imminent chances of an upgrade are a bit slim. The existing model would be another candidate for lights if it stays.

 

The "Gronk" had a lighting kit fitted very recently. That and the decoder had to be hardwired so give an indicator of the vintage. There was little room for the lighting unit so I think that will remain devoid of a speaker.

 

From memory the Class 15 & 16 bodies seemed to be full of weight. I suspect these could end up at the back of the queue for speaker fitting. I might do the same with the steam locos as well on the grounds of the perceived difficulty level of fitting the speakers.

 

The DMUs seem another matter entirely. Internal space is plentiful although it seems to involve encroaching on the seating area. However, the under floor detail appears such that there isn't too much flat space over which to fit the speakers. It'll be interesting to see whether there's any provision for speakers in the new Bachmann class 101 when it arrives. That is a definite candidate for the layout as I spent a good while using their pre-TOPS yellow diamond cousins daily and want one to remind me of my first few months of work unsupervised.

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Ray,

 

I am not sure whether fitting a speaker into a Hornby Scot tender helps you but the principle is the same.  By cutting a rectangular hole in the weight to accept a base enhaced speaker maintains the clearances in the tender and to my ears produces a good sound.

 

post-1644-0-13606400-1389871413.jpg

 

Mike

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I've fitted a Howes/ESU 21 pin decoder to a Bachmann 3F. It was very easy. The trick is replacing the round speaker with an oval one which fits between the wheels. I used the oval speaker housing that comes in the bag of bits.

 

Cheers,

 

Malcolm

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  • 5 years later...
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Can I ask a really dull question - the speaker wires do go to the two prominent soldered tags marked Spk 1 and 2? I have done so - decoder works but no noise.

Chris

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I think we may need a little more information before we can comment with any certainty.

 

Do you have a picture of the decoder (and the make/model). It might be useful to know which DCC throttle you are using in case someone can suggests some tests.

 

This may be a very silly question but have you turned the sound off by accident? Have you tries resetting the decoder (frequently done by setting CV=8)?

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Thanks Ray - I will sort some pics but I've done the factory reset etc.

I'm using a 21pin Zimo from Digitrains and have soldered the speaker wires to SPK1 and SPK2 on the small circuit board in the tender that has the 21pin plug (assuming the decoder counts as a "socket" ):

I've now tried the decoder in a 3F and 4F so if those are the correct tabs I'm stuffed.

To be fair Jeremy from Digitrains has said he'll have a look if I take it all to the GCR event where he has a stand. I was just trying to see if I could sort it myself.

Chris

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