I don't have have room for two Tang Band modules. Is there any way to match the impedance WITHOUT adding another speaker?
Mike C.
Yes, 2x 8 ohm speakers in series would be 16 ohms. You have to go by what you see in the wiring.
You can always go higher - it just reduces the volume. The decoder spec is the important thing. If it can drive an 8 ohm load, then two of the Tang Band speakers in series would be fine. It will also handle a 16 ohm load, just with reduced volume. Go TOO high and you won't be able to hear it, but it won't fry the amplifier. Go LOWER than specified and you will overheat and damage the amplifier. It'll be loud - for a little while. A single 4 ohm Tang Band speaker is not going too be a direct replacement for the pair of 8 ohm speakers currently in there, if they are indeed wired in series.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Since I was last here, I have removed the shell on the J's tender. The (2) 1 1/16" diameter speakers are clearly marked "8 ohm". BUT (and this is a BIG but), they are wired in SERIES!
So, now I assume I MUST have a 16 ohm speaker, as a 4 ohm (Tang Band) might fry the decoder?? somebody told me they were parallel....aren't two 8 0hm speakers in series actually 16 ohms?
wobblinwheel I'm pretty sure the two 8 ohm speakers in the J class's tender are wired in parallel, as I seem to remember there's two wires running from one speaker to the other. That being the case, I'm assuming that ONE 4 ohm "Tang Bend" would work ok and not damage the decoder? From the video you shared, the Tang Band with the passive-radiator sounds (to me) clearly better than the others...
I'm pretty sure the two 8 ohm speakers in the J class's tender are wired in parallel, as I seem to remember there's two wires running from one speaker to the other. That being the case, I'm assuming that ONE 4 ohm "Tang Bend" would work ok and not damage the decoder? From the video you shared, the Tang Band with the passive-radiator sounds (to me) clearly better than the others...
Depends on whether you are sure your speakers are 8 ohm and wired in series.
"You pays your money, you takes your chances". A southern variation on an Aldous Huxley quote, per my Alabama instructor pilot.
The worst case is you fry your decoder and put in a LokSound Select ($82) and the Tang Bend module. Please let us know the outcome! Most interested.
Paul
Modeling HO with a transition era UP bent
wobblinwheel I'm thinking two 8 ohm speakers in parallel still equals 8 ohms? What would 4 ohms do? Thanks for the info!
I'm thinking two 8 ohm speakers in parallel still equals 8 ohms? What would 4 ohms do? Thanks for the info!
The following link gives examples of 2, 3 & 4 speaker lashups and the effect of the net impedance "seen" by the audio amp. Check out the diagrams and focus on the impedance (not wattage) info.
http://sbs4dcc.com/tutorialstipstricks/wiringmultispeakers.html
In DC, a resistor resists current flow (and takes a voltage drop, and heats up). Higher resistor values (in ohms) mean more resistance, so a 200 ohm resistor has double the resistance to current flow of a 100 ohm. The resistance increases when resistors are put in series, so putting two 100 ohm resistors in series makes for a 200 ohm resistance seen. Still talking DC and resistors, here. If you put two 100 ohm resistors in parallel, it makes it easier for the electrons (current) to flow, much like two parallel pipes would let more water flow. Those 2 resistors in parallel then act as a 50 ohm DC resistance in the circuit.
In audio, we are talking sine waves (alternating current) of amplifier voltage change to the speaker. In AC, the "impedance" is a term, expressed as ohms, indicating the relative resistance-like effect of an item in the AC system. You can see in the diagrams of the above link that two speakers in series have additive "impedance" (in ohms), so that the two 8 ohm speakers in series makes for 16 ohms as the amp sees them. And two 8 ohm speakers in parallel makes for 4 ohms net impedance to the amp. (Ignore the minor wire resistance).
With a given decoder you need to be sure not to connect the audio output to a lower net impedance than rated. So if the decoder is rated for 8 ohms minimum, you must not hook up two 8 ohm speakers in parallel. You should somehow determine what your decoder rating is, by asking BLI or QSI (can you read a code on it?) for instance, or determine if your speakers are hooked up in series or in parallel. And can you read the ohm rating on the speakers? If they are 8 ohm each and in parallel, the decoder can handle 4 ohms. If they are 8 ohm and in series, they are presenting 16 ohms so you don't know if the decoder can handle 4 ohms net. It is likely 8 or 4 ohm minimum rated, but you need to pin that down.
parallel reistence is claculated by 1/((1/r1)+(1/r2)+(..))
1/(1/8 + 1/8) = 1/(2/8) = 4.
No conflicts with any other rules either, like Kichoff's Laws and Ohm's laws. Load in parallel add current - and less resistance equals greater current
Even if you approach it from the concept that putting two batteries in parallel does not change the voltage - it DOES increase the current capacity though, because the two batteries in parallel have half the internal resistance and thus can supply twice the current at the same voltage.
2x 4 ohms in parallel would be only 2 ohms. 2x 4 ohms in series would be 8 ohms.
The QSI speakers are wired parallel in my BLI 2-8-2. Hope this helps.
Jeff White Alma, IL
It looks like the QSI decoder has two 8 ohm speakers, according to documentation. At this time I don't know if they're series or parallel. Would the Tang Band speaker, which is 4 ohms, work without smoking the decoder? I'm pretty dumb about how this "impedance" stuff works...
Yes, the old 3.5's use 100 ohm speakers, all the newer decoders will work with 8 ohms nominal. 100 ohm speakers on the new decoders won't hurt anything, but the volume will be VERY low. 8 ohm speakers on the old decoder will let the magic smoke out of the amp. Pretty sure the factory installed QSI decoders used 8 ohm speakers, so the modern ESU 8 ohm sugarcubes should be fine. Since they are relatively small, if you have the spoace, a set of 4, 2 in series, another 2 in series, and both sets in parallel, will give you 4 speakers with a total 8 ohm impedence.
You will note that LokSound decoders vary in their speaker impedance requirements. For instance, the V3.5 decoders are designed for 50-100 ohm speakers, whereas the V4.0 decoders are rated (per the manual) for 4-8 (some go to even 16) ohms.
For the V4.0 decoders, somewhere the literature notes the decoder amp is optimized for 4 ohm speakers. Using 8 ohms makes little difference, a barely noticeably reduced max volume perhaps. Some folks have done 16 ohms, perhaps putting two 8 ohm speakers in series, for instance, and reported that there is still enough volume output for room environments. With lower ohms, one would just turn the master volume down further to suit taste.
http://www.esu.eu/en/products/accessories/loudspeakers/
Note that there is a caution on the V4.0 page, which offers the 4-8 ohm speakers, NOT to use them with the V3.5 (and some V3.0) older ESU decoders, as the much lower (than nominal 100 ohm) impedance would cause the decoder audio output to go into overdrive and nearly assuredly get fried.
This is similar to most home audio amps, which typically like 8 ohm speakers, maybe ok with 6 ohm, but often warn that 4 ohms is outside of allowable. I have some 4 ohm front speakers and need to pay attention to a potential amp purchase so that I do not buy a 6 ohm minimum amp.
So, you must choose speakers compatible with your decoder, or vice versa. Are the decoders for which you are considering speaker changes all for 8 ohm or so speakers? Perhaps call Tony's Trains, Litchfield Station or BLI for recommendations on your specific loco. Note that while the LokSound V4.0s can handle 4-16 ohms (4 ohms optimally), there are many decoders using 8 ohms speakers that are NOT ok for 4 ohms. So you need to be sure to know if you are within the decoder specs or how much risk if you try a 4 ohm on an 8 ohm design decoder.
On the subject of lower frequency capability, I suggest to take published speaker frequency ratings witha grain (maybe several lbs.) of salt. The best info comes from people who have objectively tested (measured) one against another using the same test method. That's why I am so high on the comparisons that Larry Hanlon published on the LokSound Yahoo User Group website in the Files section. You will see one speaker of similar form factor can be considerably better or worse than another. In the Micros, there is a 13x18mm CUI that is better than the (discontinued) Knowles Grand, for instance. And there are many small HO typical ovals that are way worse than a good micro or 1" HiBass. You are correct that no HO speakers can get down to the low bass frequencies that we would like, but some are much better than others at reproducing at least some lower frequency output below 500 HZ. None of the speakers have the desired flat response curves below 500Hz, but one will taper off (at lower frequencies) faster than another, the former producing less of the lower frequency output than the one that tapers off slower.
Ok, I just did some Googling for "ESU sugar cube speakers", and I see they have them in 8ohm. Boy, did I just open up a "can o' worms"..!! WAY too many choices!
Does anybody know the impedance of the ESU speakers? It seems my PCM Y6b with it's factory-installed ESU system has two 100ohm speakers. I'm not sure how compatible that would be for a decoder requiring two 8ohm speakers...? Can anybody educate me on this? I do like the idea of reaching 100hz on the low side, although I didn't think that was physically possible with a small speaker. I remember in my 1970's-era "audiophile" days, you had to move a lot of air to reach the low frequencies (20-60hz, in particular), and you had to have BIG woofers to do that! Seriously, how can something less than 1" in diameter accomplish this...?? Could you HEAR IT if it did..??
ESU sugarcube is rated down to 100 hz, the "megabass" speaker to 250 hz. So yeah, better bass on the sugarcube.
Many speakers used in our applications bottom out at about 450 hz. That's higher than A440. It's no wonder our engines sound weak.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
Lot of people are using some of the ESU Sugarcubes and finding them to sound better than some of the "high bass" ones out there. They are small enough for narrow body diesels, in a steam loco tender you could fit a nice array of them. Might even be able to stuff on in the boiler somewhere, although that means an extra pair of wires to the tender, however if at least some of the steam loco sounds come from the boiler area instead of all coming from the tender, it would be an improvement.
Not interested in "loudness" in the least, just good sound. I know back in the 70's when we wanted "high-power" stereo systems, your better speakers were mounted in very thick, heavy enclosures. Any speaker mounted in a plastic box always sounded, well...."PLASTIC"..that's exactly why I'm wondering if the same principle applies to our model trains. OR does the composition of the cabinetry really NOT have an effect on the sound of our little model trains...? My main volume is usually set between 20 and 30 out of a possible 0-255 scale. None of the typical issues with "rattling" or vibration sometimes encountered with plastic enclosures....
I found that sound quality could go up when sound volume went down.
If you think your plastic tender shell is reacting to the speaker, lessening the ability for large flat surfaces to move should help. The ideal would be glueing sheet lead on the surface. I'd guess about 1/16" thick. It will "rigidify" the surface some, and also add weight, which will lower the resonant frequency. If the added weight is a problem, you can glue Evergreen strips on. I would use .125 x .250, glued on edge. You want to break up large areas of the flat surface. Also adding strips across the volume of the tender will contribute towards stiffening the sides.
Ed
It looks like it's just over 1/2" tall. I gotta do some measuring. The factory-installed QSI decoder is a MONSTER, size-wise. I really would like to hear the J's whistle through some good speakers! I have noticed that both of my newer Paragon 2 (Pennsy K4 and H10) that sound really "deep" both have die-cast metal tender bodies. Could that be the reason they sound better? The speakers in them are actually smaller than the QSI...
wobblinwheel While I haven't done exact measurements, I'm pretty confident the Tang-Band T1-1925s module would fit inside the J Class's tender. I wonder how TALL it is, considering the existing QSI speakers are really FLAT, and the decoder circuitry is really BIG. It's a two-level board with GIANT capacitors, and other stuff (like the socket for the "chip"). The actual height of the speaker may be the only issue... the Tang-Band clearly sounds better than the others, provided the ancient QSI audio amplifier doesn't compress the frequency response so bad that NOTHING sounds better!
While I haven't done exact measurements, I'm pretty confident the Tang-Band T1-1925s module would fit inside the J Class's tender. I wonder how TALL it is, considering the existing QSI speakers are really FLAT, and the decoder circuitry is really BIG. It's a two-level board with GIANT capacitors, and other stuff (like the socket for the "chip"). The actual height of the speaker may be the only issue... the Tang-Band clearly sounds better than the others, provided the ancient QSI audio amplifier doesn't compress the frequency response so bad that NOTHING sounds better!
The mesurements are shown on the spec sheet, in mm. The tabs can be cut off the ends.
https://www.parts-express.com/pedocs/specs/264-929s.pdf
Bayfield Transfer Railway I installed a 'high bass' speaker on an old BLI SW-7 with QSI sound.It made no difference whatsoever.A friend who knows way more about this than I do suggested that it's probably because they truncated the digital sound signal at the bottom range of the speaker they put in, because early sound decoders were very short on memory.
I installed a 'high bass' speaker on an old BLI SW-7 with QSI sound.It made no difference whatsoever.A friend who knows way more about this than I do suggested that it's probably because they truncated the digital sound signal at the bottom range of the speaker they put in, because early sound decoders were very short on memory.
I have to wonder if the Tang Bend T1-1925S module would fit your tenders. If so, I suspect it might leapfrog the performance of twin 1.1" HiBass, enclosed or otherwise. The Tang Bend contains a 1" speaker and a passive radiator. A caveat is the 4 ohm design, perhaps an issue with the QSI decoder?
https://www.parts-express.com/tang-band-t1-1925s-speaker-module-2-1-2-x-1-1-8--264-944
I recalled that I am planning to add the Tang Bend to a IHC Pacific that I have in line, and I think I can squeeze it in. So perhaps it would fit your tenders. It would be tough to get it in a diesel, maybe an E unit.
I posted this (for me) fun video comparing some newer (to me) micro speakers, and used an enclosed "QSI Box HB 28mm, 8 ohm, 2W" (per the back sticker) as the comparison to the others, including the Tang Bend module. The Tang Bend is quite impressive (for HO, where it may fit). I got the lead on it from one of Larry Hanlon's articles I mentioned above.
https://www.youtube.com/watch?v=jB0IEW1jcr8
Just to elaborate a bit, the engines in question are the original "first run" BLI N&W A Class, and J Class, and Pennsy T1 and I1sa. They all have pretty large tenders, and the existing speakers appear to be well over an inch in diameter. There are two per loco, facing down on metal chassis. The shells in each case are plastic. I'm really interested if anyone has tried improved speakers in THESE (or similar) applications, as these engines have been around long enough for some to actually NEED replacing. My A Class blew one of her speakers a few years ago (maybe just deterioration) since I think it's easily ten years old, or older. I figure the others may not be far behind. I would like them to sound better, if possible. The J Class has (to me) has a pretty "accurate" sounding whistle, far better than some of the later attempts by Soundtrax, MTH, and TCS. The only real flaw in the QSI (with the upgrade chip) is the sound needs to be deeper, sounds just a bit "tinny" as it is. Of course, ten years ago, I thought it was GREAT....! Anybody already know if they are 8 ohm speakers factory installed? I really don't want to go through the time and expense, if the "high-bass" speakers aren't an improvement, or possibly WORSE...
I can't compare with the BLIs. But I acquired 2 P2K E6 units. One had a QSI decoder and dual (QSI??) speakers. The 2nd was DC, so I added a LokSound Select 6Aux and dual "Hi Bass" 1.1" speakers (from Tony's Trains) and I was quite satisfied.
More to your question, I was not content with how the QSI decoder worked (e.g., delay when advancing the throttle) and I decided to replace the decoder with a LokSound Select ala its mate, but leaving the dual speakers. Not sure if they are QSI, but maybe. I just gave a listen to the two, the same (dual prime mover) sound file on startup & idle, and the horn. I can say they are slightly different, with maybe an edge to the HiBass. But not necessarily worth the change if they are similar size. Sorry I can't find a photo of the speakers which were in the QSI decoder E6.
Overall, I don't think an HO dual 1.1" HiBass in an E unit (it fits) is a bad choice at all. I don't know if the Railmaster HiBass are different from the Tony's version. You can buy them with enclosure or make your own.
http://railmasterhobbies.com/railmaster_hobbies_speakers.html
https://tonystrains.com/product/tds-high-bass-1-10-x-0-44-speaker/
I've since done a number of diesels with 13x18mm micro speakers, making styrene enclosures (as Mel describes) to max size (that's important). I've done diesels such as GE Dash 9, EMD GP-50/60 with quad speakers and the results are also very good (considering the size constraints of HO).
If you are curious to see some interesting train speaker comparisons, from micros to ovals to HiBass to Tang Bend "module" (hard to fit in HO diesels or small tenders), I highly recommend joining the LokSound Yahoo User Group and looking in the "Files" section at some great writeups (with grapics) by Larry Hanlon comparing a number of speakers.
Sorry this is not a direct answer. If I can confirm the P2K E6 original speakers are QSI I will update.
I have four of the early Broadway-Limited engines with the original QSI factory sound in them. The sound coming out of these is kind of "shallow"(?) compared to some of the newer Paragon 2 versions. I remember BLI once offered "High Bass" speakers as an upgrade several years ago, but their website no longer shows them as an option. I notice different companies offer "high-bass" speakers, such as Digitrax (I think), in different sizes for around $9.00 each. Has anyone tried these in the old BLI models, and did they sound better? I still like the sound "ok", and I've really gotten used to using the original "Quantum" decoders over the years. I've installed the upgrade chips in all of them, and they work great. I just wish they could sound a little "deeper"...?