Speaker location?

[johncolley]

A thought has been nagging me lately. With the possibility of locating a speaker in the fuel tank on diesels, are there any bad effects on the quality of sound or the actual speaker operation due to the close proximity of the motor? Either from the permanent magnets or the current thru the windings?

[Don Gibson]

KEY to speaker performance is Baffling (not to be confused with the word 'puzzling').

A 'BAFFLE is a 'Separation of the the speaker's back wave from it's front wave. The bigger the Baffle the bigger the sound since it prevents sound wave cancellation of front to back waves...It effectively makes the speaker more efficient over a broader bandwith..

PROBLEM is where it is convenient is not always where it will sound best.

FUEL TANKS on some locomotives may be convenient ,but due to open wheel wells next to it, a poor baffle. A speaker fit against an OPEN ROOF FAN can use the entire body as a baffle. If I use the inside of cast Fuel Tanks - such as Stewart - I cut a 1'8" board to fit and seal-off the open wheel wells and mount the speaker (firing down) over a hole in the board. The holes in the fuel tank bottom (and wheel wells) carry the forward motion and the body then seals off the back wave as far as the doors.

The above works best within a DUMMY unit as the motor and drive take up most all the room in a powered unit. The BLI units (to date) have been largely successfull by using Steam Tenders as a trailing Dummy unit with speakers inside and - sealing off the the front from the rear. Sound firing down is as good as sound firing up, as back waves and front waves carry the same information - moving back and forth,

If all this is too formidable for you ther is an encapsuleated speaker @ $24 that is about 1.5"x 1.5" x .5" that can fit next to the roof of an F unit, and will provide sound with the front windshields removed.

[Anonymous]

Life Like in Canada (Canadian Hobbycraft) has announced their next run of powered RS-10 diesels (Canadian version of the ALCo RS-11) will feature "stereo speakers". I assume stereo means two speakers. Wonder where they will place the second one?

Perhaps some advertising fluff?

Bob Boudreau

[Don Gibson]

QUOTE: Originally posted by FundyNorthern

Life Like in Canada (Canadian Hobbycraft) has announced their next run of powered RS-10 diesels (Canadian version of the ALCo RS-11) will feature "stereo speakers". I assume stereo means two speakers. Wonder where they will place the second one?

Perhaps some advertising fluff?

Bob Boudreau

BOB: There can be NO stereo effect unless (1) the source material has been recorded in two separate channels/Tracks; (2) the speakers have to be a 'set' distance apart - such as head-end and tail-end of a train in HO.

Since all commercial sound sources are Mono - BLI / OMI / Soundtraxx / MRC - about the only thing any 2nd speaker could be used for is 'Reverb' or Echo.

[Anonymous]

QUOTE: BOB: There can be NO stereo effect unless (1) the source material has been recorded in two separate channels/Tracks; (2) the speakers have to be a 'set' distance apart - such as head-end and tail-end of a train in HO.

Since all commercial sound sources are Mono - BLI / OMI / Soundtraxx / MRC - about the only thing any 2nd speaker could be used for is 'Reverb' or Echo.

I never assumed there would be stereo sound, I was just pointing out what Hobbycraft has placed in their magazine ad - "stereo speakers" (Canadian Railway Modeller magazine). They've been known to bugger things up in the past, so I assume this is just more of the same and there will only be one speaker in the fuel tank. Perhaps their ad people need a facts checker?

Probably too they are using "stereo" to indicate "high quality" or something along that line.

I could never see the reason to promote TV sets with "stereo sound", when they have two speakers only a foot or so apart. You'd only get the stereo effect with wider placed speakers.

Bob Boudreau (in mono!) [:D]

[Don Gibson]

quote: Bob Boudreau:

QUOTE: " I assume stereo means two speakers. Wonder where they will place the second one?"

Your just being too polite to say.

[rexhea]

One thing you can always do with a diesel, if you don't mind pulling a boxcar around all the time, is to install a speaker in it and connect it to your loco's decoder. I put a large oval and a round speaker in a box car and the result has the neighbors complaining. [:D]