Improving sound in a modern (low end) tender

Can you post a pic of how you did that?

Mike, that's a good idea. Speaker boxes usually have fiberglass insulation inside them to reduce unwanted sound wave reflections inside.  You might try gluing some fiberglass insulation to the inside of the container, leaving more free air space inside the container than the volume of the insulation.  Also, make sure that the fiberglass isn't touching the cone (black paper) part of the speaker so it doesn't add a buzzing sound.  You could also try securing the container around its rim to the inside bottom of the tender with either hot glue or some other non permanent adhesive.

I haven't tried this yet.  If you do, please let me know if it sounds better to you.

If the speaker itself is lacking, an upgrade to a better speaker could help. Sometimes the sounds aren't there to justify it.

Sometimes they use a bottom end speaker that doesn't reproduce all the frequencies. Sometimes they self destruct over time (magnet flaking?).

I put a better speaker (4 ohm peerless) in a 3rd Rail Niagara MTH PS install and got really good sound from it. Cost like $20. Money was worth it.

Spray can tops also work.

For the sizes of baffles for our model trains, I doubt that adding insulation is going to make a huge difference, the major improvement is simply the presence of the baffle vs. the bare speaker as it done for many models.  I suspect the reason that Lionel sound is typically better than MTH sound, especially for steam, is the fact that Lionel uses a decent baffle on almost all their steam products.

   For this application, in a locomotive, would an opening (port) be a necessary for a DIY speaker enclosure?   I recall my massive speakers (dual 32" woofers) from the early '80s had ports.  During a especially bass heavy song from the likes of Led Zeppelin or Miles Davis, they would really push out a lot of air through the ports.  

   Naturally I'm not expecting this from my LC+ GP7, but just curious if factory speaker enclosures are ported  

Tom

A little trick that I use to add an easy already made baffle to my tenders  can be found at your local truck stop (FREE) or purchased online for not much money.

I pickup a a few of the the "sauce" containers that are available for individually packed cheese or ranch dip. Almost all are tapered and have anywhere from an 1 3/4" - 1 15/16" opening that fit perfectly when mated to most hobby sized speakers. A little hot glue to hold and seal it in place and you have an instant easy to install baffle.

If there is more height available, I have also use Red Solo shot cups. They tend to be a bit taller but can be easily modified to be made shorter.

@FlyPlanes-PlayTrains posted:

   For this application, in a locomotive, would an opening (port) be a necessary for a DIY speaker enclosure?   I recall my massive speakers (dual 32" woofers) from the early '80s had ports.  During a especially bass heavy song from the likes of Led Zeppelin or Miles Davis, they would really push out a lot of air through the ports.  

   Naturally I'm not expecting this from my LC+ GP7, but just curious if factory speaker enclosures are ported  

Tom

Most of the small speakers that Lionel uses to good effect have no ports, I think for the size of the speakers involved, I'd skip trying to figure out ports.

I hasten to add, even a tiny speaker "can" benefit from ports, but I suspect there's a lot of acoustic design work involved in laying out exactly where and how big the ports are.  One only has to disassemble a few old laptops to see how the sound engineers make laptop sound so good with such tiny speakers.

I want to add an identical speaker to my polar express 5.0 tender with the baffels. What is the Lionel part number? The current speaker is stamped 8 ohms, 3 W, and measures 2" or 50mm. Just under the width of the tender.

@Santa Bill K posted:

I want to add an identical speaker to my polar express 5.0 tender with the baffels. What is the Lionel part number? The current speaker is stamped 8 ohms, 3 W, and measures 2" or 50mm. Just under the width of the tender.

Identical to what?

@gunrunnerjohn posted:

Most of the small speakers that Lionel uses to good effect have no ports, I think for the size of the speakers involved, I'd skip trying to figure out ports.

I hasten to add, even a tiny speaker "can" benefit from ports, but I suspect there's a lot of acoustic design work involved in laying out exactly where and how big the ports are.  One only has to disassemble a few old laptops to see how the sound engineers make laptop sound so good with such tiny speakers.

While I fully agree that crafting ports and enclosures to produce a wide range of fidelity across the audible range is a real challenge best left to audio engineers, almost *any* effort to increase the distance sound has to travel between the front and rear of the speaker will result in significant increases of volume produced by the speaker, especially with the lower frequencies. It's like the difference in trying to stir your coffee with a straw, or with a teaspoon!

It doesn't have to be elaborate, either -- *anything* that increases the distance air has to travel between the front and back of the speaker will help. For instance, when I installed crossing bell modules, the tiny speakers could barely be heard above the ambient train sounds. To give them a boost, I centered the speakers in rings of foam board, then glued the rings inside half-length toilet paper tubes, which also provided cover for mounting the modules next to the speakers. I got a good 2-3 times boost in volume over the bare speakers IMHO:

Note: in the test video, my DIY "ported" speakers are in the white tubes visible near the crossing gates, but even after their subsequent installation below the layout, the sound is still easily audible.

So, if you can mount the speaker tightly over a grill or hole(s) in the chassis or shell, and open another hole as far from the speaker as possible, I predict you'll get a significant boost in volume over that of the bare speaker.

[And BTW, even the engineers sometimes muck it up. In another life, I played bass using, at peak, two Fender Dual Showman amps, each driving two Dual Showman bottoms, each of which had two JBL 15" speakers, for a total of eight 15" woofers. Should have been sufficient, right? Not quite -- as it happens, the speaker enclosures were *not* ported, which not only reduced the bass volume but resulted in all too frequent blown speakers when I dialed it up to "11"! Modern bass speaker enclosures are *much* better designed, with ports and enclosures that both enhance the bass response *and* reduce the back pressure that can damage the speakers. *sigh*]

Just adding a baffle will accomplish the goal, at least IMO.  I don't see any additional volume or bass response using a tube over a baffle.

@gunrunnerjohn posted:

Just adding a baffle will accomplish the goal, at least IMO.  I don't see any additional volume or bass response using a tube over a baffle.

Oh, I agree -- IMHO, the key is increasing the distance between front and back, and anything that does that, no matter the shape, should increase the speaker's ability to convert the electrical signal to sound volume. A lot of speaker enclosures use such baffles to route the sound back and forth in the enclosure, lengthening the path air has to take to get from front to back of the speaker. I just used a tube because it was near the size of the speaker, and provided a convenient place to stow the sound module. Mounting a speaker under a hole through the layout would also work, with an even longer front-back path.

The speaker in the Polar Express Tender spans the full width of the Tender and the speaker measures 2" square frame and 2" diameter. It has a large magnet with 8 ohms and 3 watts stamped on the back of the magnet. I am asking if anyone has access to the Lionel documents that would list what the part number of the speaker is so that I could buy another from Lionel just like it to add in parallel with the one in the Tender. That should provide the amp  with a 4 ohm load, and hopefully not overload the amp, but would provide more sound and power. I want to baffle both the existing speaker and the additional one. I plan to put separate baffles or each speaker and mount and seal them with hot glue I will have to make holes in the floor of the tender, like the original, for the grill of new speaker then mount it with screws and nuts.

@Santa Bill K posted:

The speaker in the Polar Express Tender spans the full width of the Tender and the speaker measures 2" square frame and 2" diameter. It has a large magnet with 8 ohms and 3 watts stamped on the back of the magnet. I am asking if anyone has access to the Lionel documents that would list what the part number of the speaker is so that I could buy another from Lionel just like it to add in parallel with the one in the Tender. That should provide the amp  with a 4 ohm load, and hopefully not overload the amp, but would provide more sound and power. I want to baffle both the existing speaker and the additional one. I plan to put separate baffles or each speaker and mount and seal them with hot glue I will have to make holes in the floor of the tender, like the original, for the grill of new speaker then mount it with screws and nuts.

I strongly recommend AGAINST loading the amp with half it's rated impedance!  You will most surely overload the amp!  The CE0030B amplifier chip is a 1W output into 8 ohms, pushing it well beyond that will likely kill it!  Put a baffle on the existing speaker and call yourself the winner.  The THD goes WAY up if you push the amplifier to 1.5 watts to the point that the sound will be barely recognizable!

Thanks for that insight and advice.

I will do just that!

@Steve Tyler posted:

Oh, I agree -- IMHO, the key is increasing the distance between front and back, and anything that does that, no matter the shape, should increase the speaker's ability to convert the electrical signal to sound volume. A lot of speaker enclosures use such baffles to route the sound back and forth in the enclosure, lengthening the path air has to take to get from front to back of the speaker. I just used a tube because it was near the size of the speaker, and provided a convenient place to stow the sound module. Mounting a speaker under a hole through the layout would also work, with an even longer front-back path.

I have just found that the long tube sticking out of the top of the tender is an eyesore.

@gunrunnerjohn posted:

I have just found that the long tube sticking out of the top of the tender is an eyesore.

. . . not to mention the wind resistance!

[OTOH, you could mount several lengthwise as a flat car load! Yeah, that's the ticket! ]