Need help on choosing a Knowles or any other 8 ohm speaker for a sound decoder on an HO Atlas U33C Locomtive.
Any suggestions?
Thanks
[#welcome] to the forum, your first 10 posts are moderated, so there will be a loag time before they appear here.
I used the search box on the right side of this page and the first thread I encountered was from 2014 and talked about the need to mill the frame to have room for the speaker. I also see there are DCC with sound locos on Ebay so I infer there are newer models. What exactly do you have?
http://cs.trains.com/mrr/f/744/p/228635/2555110.aspx
Hadn’t heard of the Knowles speaker from Digikey, but it looks like the standard sugar cube speaker offered by other sources. There are lots of youtube videos using Knowles speakers. I haven’t seen discussions of one brand vs another. There are people here who are fans of using two speakers. None of my conversions have had the luxury of that much room.
You need a speaker enclosure. That is a simple DIY project using a bit of styrene. You also need a sound decoder. As this is your first post, we don’t know what you don’t know. A DCC loco, that is not sound equiped, has a non-sound decoder, so you need to upgrade the decoder to get sound out of it.
I am not familiar with the speaker but I have done some diesels with 28mm round and made styrene baffles and also 25mm x 35mm speakers with styrene baffles. They worked ok for me.
I used Tsunami and LokSound decoders.
It has been some years. I think the styrene was about 1/16 inch thick.
Rich
Thank you for your response.
I have an Atlas U33C silver/ready loco with the original motherboard.
Finding the sound decoder is the easy part, the hard part is that there is no space in that skinny shell!
I surfed the net and found older post where some modelers used Knowles 11mm x 13mm and 11mmx15mm speakers which they purchased at Digikey.
Problem is when I went on the Digikey website, they no longer stock those two sizes.
The sound decoder that I have ha a speaker which is 28mm round and way too big.
Digikey prices were great at less than $3.00 a speaker and I do not want to spend $10-15 from other sources, since I have already spent a lot on the decoder.
The sound decoder that I purchased comes with a 28mm round speaker, that does not fit. A sugar cube speaker would be ideal, but I don’t want to spend more than $3.00-$4.00.
Digikey has other micro speakers in your price range, but their max wattage is less than the speakers I see advertised for DCC 500-700 MW compared to 1W. I don’t know if that means you would blow out the lower rated speakers, or not.
That loco (see link) looks alot like an Atlas C30-7 I am doing.
http://tcsdcc.com/installation/ho-scale/atlas-u33c-u36c/t1p-sh
In my case, I had to decide on milling the frame vs. squeezing speaker (w/enclosure) into existing space. I decided on the latter, just for the challenge, since I like to see how I can optimize an installation. I removed the existing circuit board, filed down the motor vertical protrusions and added a strip of 0.015" styrene and put my LokSound Select shrink wrapped decoder atop that. Also changed the bulbs to 5mm LEDs.
Re: speakers, I like to add 1 or more 13x18mm speakers in custom (CA glued) 0.040" styrene enclosures. I decided in this case to see if I could fit two enclosures for 13x18m speakers atop the flywheels. A challenge. I made two, each about 12mm high. Since wires would be atop the flywheels, I added 0.015" styrene strips just above the flywheels (glued at one end to the weights). This was a real squeeze. I found the enclosures, place with the long dimension across the shell, just a bit too wide, so I sanded them (the walls) slightly thinner after assembly and they just slip in against the walls.
On the speakers themselves, I used to use Knowles Grand 13x18mm (they replaced a well received Dumbo) but they have been long discontinued. So I switched to CUI TDS-18138A from DigiKey. I have used these in multiple locos, in configurations of 2-4 speakers typically. I like the results. Do make any enclosure as large as practical. It makes a significant difference.
Hello Paul, Thank you for all the great information. I went on the Digikey website and ordered the speakers. Cheers!
I did not have photos the other day so am adding some here, hoping the interior of the C30-7 is quite similar to your project. I needed to go back in today as I was suspicious of a potential connection problem. One of these days I will learn to take photos during every project.
C30-7 A (2) by Paul Ahrens, on Flickr
C30-7 B (2) by Paul Ahrens, on Flickr
C30-7 C (2) by Paul Ahrens, on Flickr