MTH DIESEL SPEAKER REPLACEMENT SUGGESTIONS

New replacement speakers from MTH are higher quality than the originals. I have replaced many and no problems.

If you can, try to totally baffle the rear of the speaker, that will do wonders for the sound.

gunrunnerjohn posted:

If you can, try to totally baffle the rear of the speaker, that will do wonders for the sound.

John, what do you use for the baffle? Thanks!

bigtruckpete posted:

gunrunnerjohn posted:

If you can, try to totally baffle the rear of the speaker, that will do wonders for the sound.

John, what do you use for the baffle? Thanks!

Good question!  This will be my first replacement.  Suggestions?

The guys gave you all good info.   The current Veco speaker is a good one.  While you are at the GS-4 it is a great idea to throw in  a fresh battery.

something rigid that can be fastened to create an air-tight seal around the back of the loudspeaker. The enclosed volume of air should be as large as possible given the space constraints you are working within.

Whatever fits, and as Rudy says, the bigger the better, within reason.  I've found that the speakers that use the whole tender as a baffle don't deliver nearly as good a sound as a smaller baffle.  Stuff like lids from spray cans, or even cut off Styrofoam cups work pretty well.  For speakers in fuel tanks, I just try to seal the hole over the tank as good as possible.

There is an ideal enclosure volume for a given driver. It will give the flattest low frequency response. A smaller than ideal enclosure gives a boost in the mid bass at the expense of the lowest frequencies. Smaller enclosures may sound better due to bass boost but they are not as flat or deep.

The dark blue curve below is ideal and might be the output of a driver in a large tender. The light blue curve might be the output of using something the size of a aerosol paint can lid.

I suspect the size of the speaker and it's driving capacity has a large effect on this.  FWIW, Lionel, which has pretty good sound as a rule, doesn't use the full tender as the baffle, but rather with their dual speaker setups they use a baffle that isn't nearly as large as the full tender shell.  Let's take the best sounding locomotive I have, the VL-BB.  I've also included the great sounding Vision Line Hudson baffle for their dual speakers.

Either Lionel doesn't know what you know or they know what they're doing when they size the baffles.  Clearly, there's no reason the Vision Line Hudson couldn't have just omitted the baffle if it would have yielded better results.

Tender speaker baffle at the rear of the tender

Locomotive speaker baffle

Vision Line Hudson Dual Fat Boy Speaker Baffle

The speakers mth uses in their diesels for the most part are 50mm or 2" exceptions are switchers and the Baldwin DRS' 616. The speakers from all electronics with their bigger magnets fit and sound nice. Just verify if you need a 4 ohm or an 8 ohm speaker.

Reading is fundamental John. The curves hold true for any speaker regardless of size. Its their relative size that differs. I have not calculated the ideal enclosure for a single or dual Lionel speaker but I could just as you could. Just look up thiele small parameters. I suspect Railsounds knows but is limited by how much space is inside the tender. As he points out bigger is better and even those large enclosures may reflect a compromise. Other considerations include what is the frequency content of the sound file. Maybe there is no need to reproduce the frequencies below 150hz if they aren't there.

Pete