Hi MRR,
I'm installing a WOW Sound decoder. The TCS wiring diagram indicates two purple wires, simply labeled A and B. Does anybody know which one is positive and which is neg? I want to get the polarity correct so the "phasing" will be correct. Does this make sense?
thank you!
If you're using only one speaker, it makes no difference. The only time phasing comes into play is if you're using two speakers.
thanks cacole for your reply. really helps. But what do you think of this guy's comments particularly 1/2 way through the short video? He say's if polarity/phasing is not correct, even with one speaker, there will be less base, ghost-like tone, etc. https://www.youtube.com/watch?v=TFlwINTNFqg
Not sure where he would get that idea from, sound waves vary equally to either side of the center point, so it should make absolutely no difference which way you wire a single speaker. half the time the cone will move forward, half the time it will move backwards. You will get muddy sound if you don't place the speaker in an enclosure of some sort, and the back half sound waves cancle out the front half.
Cacole is absolutely right, speaker polarity only matters when you hook up more than one. In that case, you want them all in phase so they all move the same way at the same time. If one is moving forward while another is moving backwards, you will cancel out the sound.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I plan to add a second speaker, just not today. So I want to get the polarity correct now.
The enclosure is all set, it's a Genesis SD70Ace with the round verticle housing as I mentioned previously. But thanks for the input.
Cheers!
Still no worries. The speakers themselves should have + and - markings. Connect the first one for now, polarity does not matter. Later, when adding the second one, you will need to make sure of the polarity. For series wiring, the - of the first speaker will connect ot the + of the second speaker. And the wire that used to go to the decoder from the first speaker's - will now go to the second speaker's -. The connection between the two speakers is where the polarity matters, not the connection from the speakers to the decoder.
thanks again Randy. My speaker does not have a (+) or (-) marking on it. It is a simple PUI 28mm, 8 ohm, 80dB round speaker. I could assume the (+) is on the right but then I could very well be wrong.
Do you know what speaker 'excursion' is? Unless this speaker does not do that, it is important to get it right. Comments?
tried that. I have a multimeter and set it on continuity check. the speaker is so small you can not positively see if the diaphram is moving in or out. how 'bout that.
Does one terminal have a different shape or something? Sometimes that is used to distinguish the polarity. If you use two otherwise identical speakers, you can be reasonablly sure that if int he same orientation, the left terminal is the same on both speakers. Of course you MIGHT get a dud that some joker at the factory wired backwards. Trial and error works well - use clip leads or something without soldering the connections to test (just don;t let anything short!). It will be quite obvious if they are in phase or out of phase (if in doubt, just reverse one speaker and compare).
JimMac:
Hi!
I am a little concerned about your desire to add a second speaker to your WOW Sound decoder. Adding a second speaker changes the impedance (resistance) of the speakers. TCS recommends using a single 8 ohm speaker. If you add a second speaker the combined impedance will be either 4 ohms if they are wired in parallel, or 16 ohms if they are wired in series. I couldn't find any reference in TCS's technical data which addressed using more than one speaker, so I would strongly suggest contacting TCS before installing a second speaker. It may be no big deal, but if the second speaker might mess with the decoder it would be best to find out in advance.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
If you want to use two speakers, check out ESU's line of 4 ohm speakers. Use two of them wired in series for the proper 8 ohm load for your decoder.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Hi Dave,
I've been thinking about your concerns. After I get this decoder working with one speaker I might try a second. Yes, of course I'd drop the impedance to 4 ohms on each. Additionally TCS may not recommend a second speaker but here's an article from Tony's where they endorse this application. I welcome more of your thoughts as I work through this...
Posted by fisker76 on Feb 10, 2015 in Locomotives, News |
Buy Now This is a Tony’s Special Package! You will get your choice of a new Genesis Union Pacific or Pennsylvania GP9 locomotive with an awesome new TCS WOW Diesel sound decoder #1530 and two of our incredible sounding, all-new, TDS Supersonic Mini speakers with enclosures. We are offering this $465 valued package to our customers for just $319.95! Don’t delay, order yours now while stock availability is guaranteed! The deadline for pre-orders on these...
Tony's web site indicates that the TDS Supersonic Mini speakers are 8 Ohm, and they don't say in the above article if they are wired in series (16 Ohm) or parallel (4 Ohm).
I spoke with the folks at TCS about the wow decoder and speakers. There is no problem using 2 of the 8 ohm speakers wired in series.
You could install 4 speakers, in series-parallel. Wire 2 speakers in series (x), then wire those sets in parallel. You get back to 8 ohms. Have fun trying to find the space for that. I considered it in a large steamer, then I just went for 1 large 8ohm speaker instead.
Sure! you could do that... IF you wanted to completely redesign the locomotive's internals by milling the frame down then redistributing the weight, perhaps change the motor out, strip the electronics out and etch your own pc board with only the necessary pads to support speaker inputs spread across the length, find a small spot to hide the smallest Lok sound decoder and plant the speakers using 36awg, 1/4 inch length wire to the aforementioned solder pads on the board cause you won't have room for any lengthy wires. Remember you'll need room for enclosures that are 1 and 1/2 times the depth of the speaker itself. Sure you could do it but you have to really want it. Or you could simply install one tiny iPhone 4/5 speaker get amazing sound quality and be done with it. Listening to one is proof positive. Got a chance to do this thanks to Kaylee at the NERPM meet Friday. Cheers!
Actually speaker phase does matter even with only 1 speaker. Not so much for the tiny speakers in model RRing. Speakers make sound by moving air, lower frequencies move more air as the speaker size is greater. Say for a bass drum when the drum is struck you want the speaker moving out towards the front, much more effiecient than sucking in. I owned and operated a production company for 40 years. Multiple speakers must be in phase with each other and going forward (in phase with power amps) So for 1 speaker in a loco I don't think, or know for that matter if it matters?
Not sure if this adds to the conversation :(
Good argument for trying it both ways, using alligator clips, to see which polarity gives the best sound.
JimMac Athearn Genesis HO GP9 & GP9B w/Tony’s Installed TCS WOW 1530 Posted by fisker76 on Feb 10, 2015 in Locomotives, News | Buy Now This is a Tony’s Special Package! You will get your choice of a new Genesis Union Pacific or Pennsylvania GP9 locomotive with an awesome new TCS WOW Diesel sound decoder #1530 and two of our incredible sounding, all-new, TDS Supersonic Mini speakers with enclosures. We are offering this $465 valued package to our customers for just $319.95! Don’t delay, order yours now while stock availability is guaranteed! The deadline for pre-orders on these...
That's $100 more than the factory Tsunami sound from other online retailers. Is it worth it?
Henry
COB Potomac & Northern
Shenandoah Valley
I guess if you can't do it yourself - because you could buy a non-sound loco, the WOWSound, and the speakers for a lot less than that. Don't know of Tony's speakers are that much better than similar ones offered by other suppliers like Litchfield, Ulrich, or SBS for the same or lower price.
Shop carefully on eBay and you might be able to buy one with a Tsunami PLUS the WOWsound, swap the sound decoders, and resell the Tsunami to get some of the cost back and come out way ahead.
There's sometimes a small red mark on the positive terminal as well.
And YES polarity matters even with single speakers. As a general rule of thumb you want to drive speakers outwards. The surround (Which acts as the damping spring and the magnetic force that causes the driver to move in the first place may not react as expected if you wire them backwards.)
I covered this about a month or two back in another thread.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!