I recently got my new spectrum dash 8 and Im going to put a LokSound decoder in it. But I need some advice on the speaker to use. The decoder comes with a .91" round speaker which will fit in the loco. But there is also a 20mm x 40mm oval speaker I was looking at. Which of the two would generally deliver the best sound?
Thanks.
generally the larger the speaker the better the sound . unfortunately i don’t remember enough of high school math to tell you which of your choices is larger , i’d guess the oval
Is the oval a 100 ohm speaker? If not, you can’t use it. LokSound abandon the standard 8 ohm speakers.
It is the strength of the magent and the sturdiness of the enclosure that matters the most.
Cheap magnets produce cheap sound.
If after you put in the speaker you strngthen the sides even a little but thickening them say, with pieces of styrene, it will improve the sound. I use to make my own speakers and found that was what was important.
I hope that helps
JPM,
I have only used the round speakers with the Loksound decoders so I can’t help you much with the sound quality questions, but a quick check of the ESU website shows they do have a 20mm X 40mm speaker available. You may want to consult the Loksound Yahoo group as there is a ton of useful information for all things Loksound related. Here is a link: http://groups.yahoo.com/group/loksound/
Good luck!
Jeff
PS> As someone else mentioned above, make sure you only use the 100 ohm speakers from ESU with these decoders… [;)]
Yes it is a 100ohm speaker, if you look on the LokSound site they offer a 20mm x 40mm oval. Since they are both from LokSound I would think the magnet strength would be the same.
I have another question, since it comes with the .91" speaker anyway, can the decoder handle 2 speakers? (1 .91" round and 1 20mm x 40mm oval)
if you link up both speakers parallel the total speaker resistance will drop to 50 ohms
so the amps running through the speakers will double up, which could cause damage to the sound chip (it would make more sound though)
if you link the speakers in a series the impedance will double to 200 ohms, it is possible the sound chip can handle this, but
the sound will be softer.
[2c]
Cerwin Vega makes some real nice ones.
OK.
Then
0.91" diameter speaker (since pie are square) = .65 square inches.
20mmx40mm square (not oval) = 800 square mm or 1.24 square inches.
So the 20x40 mm is going to move almost twice as much air.
This is no contest in my opinion.
In high fidelity, high quality equipment the square speakers are a problem since the cone movement is different on the short side vs. the long side. In this case for the scale and sound processor I doubt there will be any noticeable distortion.
That sounds like a question for ESU. I can’t find anything about multiple speakers on the web site or in the manual(s). If this was a normal audio application you could go with 4 speakers (two in series, in parallel with another two in series), but since they are “specially adapted” speakers, “normal audio” theory and practice that, lupo pointed out, might not apply.
The manuals are rather devoid of important technical information. I did find out that the processor is 1.5W and that the LocSound XL uses special 32 ohm speakers instead of the 100 ohms of the regular LocSound. But nothing about what “specially adapted” means, the frequency response or harmonic distortion at various impedance loads.
I’ll have to email ESU about it i guess. What you say makes sense, but there is also a picture on the site of a steamer with 3 speakers in it. I dont know if that is large scale or something but it looks to have a rivarossi motor in it so Im thinking HO.
The REAL DEAL is how you ‘baffle’ what you have,
An Oval speaker firing upwards through an open fan uses the whole body as a baffle. The 'baffle’s job is to separate the ‘push’ wave from the ‘pull’ wave. Since this separation limits cancellation, further is better.
A 100 OHM speaker is a puzzle. It would indicate to me that LOK sound prefers them for their audio amplifier , or it was cheaper for them to buy. Accepted universal standards are 4 or 8 ohms. Speakers vary from 2 ohms to 32 ohms depending on the frequecy being measured. They are rated ‘nominally’.
They went with the 100ohm speakers to eliminate a bulky capacitor in the circuit. And as for baffles, the speakers come with baffles so It should be covered.
Interesting. The capacitor is basically a passive crossover limiting the lowest frequencies sent to the speaker. How does the speaker impedance effect that? That just shows my ignorance. Does this mean a high ohmage speaker doesn’t even attempt to respond to the lower frequencies?
Dont ask me, I dont know how it works[:D]. I read that in Tony’s "(tonys train exchange) review of the decoder.
Joe: I vote for the smaller rectangular speaker firing through an open fan unless there is something weird going on in their amplifier. First off a .9" speaker isn’t going to fit a standard diesel, unless it’s a Alco PA.
Matching a speaker’s impedance to an amplifier, results in more efficient transfer of power. Tony’s ‘bottle cap’ baffles - seal off the back wave - but also push up the resonant frequency and eliminate any chance of sound reinforcement from the back wave.
Tony’s speaker specs show little low end to start with - 700 - 1000 cps. A 1" speaker using 3 sides of a typical 40 HO car can produce almost 2X the power and one whole Octave more bass (to 400cps). Want proof?
Take a sheet of paper, fold around a 40’ box car using top and 2 sides.
Transfer this to a sheet of Sytrene with a 1/2" - 3/8" hole in the center.
This now represents the amount of baffle - (front back separation) a car can provide.
Take the speaker, connected to an amplifier or sound module, and listen to the difference the baffle makes when the speaker is placed over the hole.
BLI’s sound is better because they use 2 speakers to move air, and … (at least in their steam) use the tender for it’s large baffle.
CAPACITOR?: Probably used to block DC from the analog audio section…