Replacement 4 Ohm Speakers?

I don't know what a "PT" tender is, but I have installed three of the Peerless TC6FD00-04 2 inch speakers in my Railking steam engine tenders without modification(they fit).

Also put one in a Railking scale FP-45.  

Here is a NYC PT Tender. The sides curve in at the bottom so its about 3/8" narrower than it is at the mid line. The Peerless speaker you point out would be my first choice but  it won't fit in the opening.

Pete

WWW.XUMP.COM:

In site map, select Robotics and Electronics, then Components.

Near bottom of page see a 2 inch, 4 ohm speaker.  

Have no idea of quality, but can't be much worse than MTH speaker and it's on sale.

Thanks for the link Mike. I just ordered a few and will let you know how they work out.

Pete

I've had good luck with these:

http://www.asapwire.com/Produc...Code=SP50-4FC-01-010

They are too tall to fit into most MTH diesels, but fit pretty easily into most steam locomotive tenders.

That appears to be what is in the tender now. As a general rule, speakers with paper surrounds sacrifice some low frequency response compared with fabric or rubber surrounds which allow greater cone travel. It looks like it would fit though if a direct replacement was needed. Thanks for the reply.

Pete

This on might fit. 

Thanks Dale but it too looks like what I have. The existing speaker is not broken. I am just trying to improve the sound. The Peerless driver than Mike linked to would be ideal as appears to be a 4 ohm version of the Digital Dynamics Megabass speaker but I don't see an easy way to install it without major surgery to the tender.

Pete

Not sure how the speaker is mounted in your model, but I just finished an upgrade to a 263E.  The speaker is mounted vertically in a carboard cylinder.  The Carboard is screwed in to the shell.  This is a very restrictive tender, I thought the mounting was novel.  G

Instead of major surgery to the tender, how about minor surgery to the speaker? Grind down the perimeter of the speaker a little on opposite sides and you might get enough room for it to fit. Just don't go too far into the outer ring of the speaker cone itself.

Rich, I expect I will have to do that with about any speaker I use. The Peerless TC6FD00 that Mike Suggested and would be my first choice as well has very little extra frame material around the cone. I would have to remove .080" from each side to have it fit without removing material from the tender shell.

 I've ordered a similar speaker advertised as 2" but less expensive that I can afford cut up. I'll post some pics if it works.

Let us know how you keep the metallic dust out of the speaker, I imagine complete covering in plastic/tape?  G

I realize that could be an issue. I am hoping I can use tin snips but we'll see. This is the one I ordered. At 99 cents I don't have too much to lose.

Pete

I would use "painters tape" to mask off every part of the speaker when cutting the metal as you don't want any chips in the cone or stuck to the magnets. These have a way of eventually finding their way into your circuit boards over time.

This on might fit. 

 

http://www.allelectronics.com/...4-OHM-SPEAKER/1.html

 

These were so cheap I ordered some with other components I needed. Have not tried one yet but they look OK.

 

Dale H

Any chance of epoxying the speaker to the tender sides or RTV silicone to 'glue' to the sides of the tender higher up where it will fit?  JB Weld might work too.  Since we don't throw or drop the tenders all you need is something that will hold the speaker in place.  You may need to use some 2" pieces of L channel to the side of the tender first then mount the speaker on the channels.  Just a thought without having to risk damaging the speaker. 

I use high temp gasket compound pictured in this thread. Holds well is elastic and can be easily removed. Be careful not to slop it on the cone excessively. I buy it in the automotive section at Walmart.

http://www.jcstudiosinc.com/BlogShowThread?id=621&categoryId=426

Dale H

Mounting the speaker in the tender shell is a possibility. Two problems to overcome if I do that is I have to route the tether around the speaker as the speaker is mounted in the front of the tender and also sealing the edge of the speaker frame to the the tender frame. Assuming the tender is sealed when I install the frame it acts as the enclosure. If the speaker is not touching the frame I would lose that acoustic suspension effect and the low frequencies I am trying to improve.

Dale, I am familiar with the red high temp Permatex. I rebuild motorcycle engines where it has a number of applications.

Pete

 Things you have probably thought of:

Try adding a closed short baffle tube to the back of the existing speaker to tighten the bass sounds.

 MTH has a new speaker in my diesels that have a foam surround. Might fit with better bass?

 It's probably the sound set as well? might have to much shrill? Any more modern set that's available that will match the board?

I'm trying to find a good speaker for diesels that is 2" by 5/8" tall so it will fit in the tank, with little luck.

Has anyone found one that isn't too tall for diesels?

The PT tender does present a unique problem but not one that can't be dealt with.

You can take a piece of oak board 1/2 inch thick and cut it to the width of the tender.
Use a Forstner bit to cut the diameter for the speaker and bevel the sides. make a baffle for the back side of the speaker or let the tender be it's own baffle.
put some epoxy on the part of the board that will rest against the sides of the tender. Slide the speaker assembly into the tender and rotate it to fit. When you put the shell back on it'll sit up against the board so I suggest some 3M double sided tape cut and bent around the board so it's padded against the shell.
This will let you use the bigger speaker by spacing it out from the taper at the bottom.

David

Here are some pics to demonstrate the problem:

Here is the stock setup showing the opening in the tender shell with little room to enlarge and also how the 2" speaker actually overhangs the frame:

The opening is exactly 2":

Here is my 99 cent speaker.Clearly larger than 2" but I was able to work in inside the shell but without a baffle. Adding a baffle would likely make it impossible to wiggle it into the shell.

Here is the last version of the Digital Dynamics Megabass speaker. The edge of the frame could be ground away to make it fit and a baffle could be installed and all mounted to the frame.

Unfortunately its an 8 ohm speaker.

So, how many adventurous souls have used an 8 ohm speaker in a 4 ohm MTH system? I would expect it to not damage the amplifier but it could suffer from lower volume. What say you?

Pete

Never did it but I would guess that the 8 ohm replacement is a lot more efficient than the cheap stock 4 ohm one and volume would not suffer.

On brass tenders I have had good luck with no baffles as the tender shell itself kind of serves the purpose.

Dale H

See my post above! My suggested Speakers WILL fit! I use them in the MTH fuel tanks of dummy diesels with NO problems!

This on might fit. 

 

http://www.allelectronics.com/...4-OHM-SPEAKER/1.html

 

These were so cheap I ordered some with other components I needed. Have not tried one yet but they look OK.

 

Dale H

Norton:  Have you (or anyone else) had a chance to try these yet and compare the sound to the MTH kit speaker?

Curve,

 I am looking for a speaker with improved performance. A flat paper cone with limited travel will have very little bass capability. Compare the sound of a new Lionel Legacy system to a typical older MTH engine. The MTH has a very thin sound by comparison.

Kerrigan, I haven't tried this but from experience would guess it would sound nearly identical to the OEM speaker.

Check out the speakers fom Madison Sound that Dale recommends. You'll see the construction is very different from the MTH driver. Composite cone material with a roller rubber or plastic surround and large magnet.

Pete

At $1.25 each I'd question how much of an improvement they would be over OEM, if any.

I've learned the hard way cheap ain't necessarily better.

Here is the first attempt at a replacement speaker. This is one of the 99 cent speakers I picked up that appeared to be more promising than the OEM speaker. The flange on the replacement has been ground off and a 2" O ring applied to keep the suround from touching the frame. OEM on the left:

Side View showing the larger (not necessarily better) magnet.

I was able to fit the modified replacement in the tender. The only alteration was the battery holder had some material on the end removed where it was hitting the magnet.

I did not fit a baffle as I didn't have one handy that would fit. A small paint can top was very close (diameter greater by .1")  but no cigar. The sound was only slightly improved. Adding a baffle may help the low end slightly but I am coming to the conclusion that the MTH sound set does not contain much low frequency. I was trying to improve the quality of the chuff sound. It sounds better to me if I use "labored chuff" but that is lost when the button is released. MTH labored chuff is about the same as Legacy standard chuff.

I don't think I will try other speakers until I can verify the frequency content of the audio signal, something I have the capability to do with a calibrated mike and spectrum analyzer (FFT). To be continued.

Pete