RandyWales Posted June 12, 2014 Share Posted June 12, 2014 Hi again... My involvement with this thread began due to the possibility of saving money by 'consisting' an offboard sound decoder/speakers with onboard motion-control-only chips. I was impressed at the time, but became disillusioned when I realised that the sound quality left a lot to be desired. To cut a long story short, I strongly believe that poor (decoder-derived) sound quality is due to the extreme compression of the sound samples when the project is compiled. I'm surprised Pauliebanger hasn't acknowledged this in his article on speaker installation in the current issue of Hornby Magazine. It's not all about the speakers. In my opinion, soundtrack-quality sounds played back through offboard speakers in the smaller scales, and streamed via Bluetooth to onboard speakers in the larger scales (and is surprisingly good through speakers normally used for 4mm) blows sound decoders away. One of my all time inspirations - John Allison - got 'Letter of the Month' in BRM August 2012 when he said "it sounds like what it is... a tiny model making tiny sounds" when referring to the sound produced by sound decoders..... Time for existing sound decoders (and the compilation software) to be shredded. I sincerely hope the next generation of DCC sound decoders is on the horizon.... Sound project compilers deserve better.... Randall Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 17, 2014 Share Posted July 17, 2014 Hi all, first post. I've set up a system where the sound chip is under the baseboard, You take two wires from the chip to the track to control the motor in a DC loco with a DCC controller, You take two wires from the chip to a speaker mounted under the baseboard, then two wires from a DCC controller to the chip. I have set this up and it works like a dream. You also get digital control of loco speed etc. It's like magic. Next step (not set this up yet) is to have more than one chip installed, all wired in parallel and all can be addressed from the DCC controller. They can be plugged into isolated track sections using stereo jack plugs (wired from the chip) to track sections. Two leads will allow you to leapfrog the loco around various sections. I then plan to move the sound around using slide potentiometers, say 3 wired in parallel to 3 speakers left centre and right. The centre slider would be reversed for ease of operation. (you could fade sound in (from say the left) with the No.1., then slide Nos. 1&2 together to transfer sound to mid-layout, slide 2&3 together to move sound over to the right, then slide 3 off to fade stage right. There would be a jack plug from each chip, via a socket, to the sliders. I need advise here, see later. This "sound installation" could be repeated for up line, down line, branch line, shed area, goods yard etc. A loco would move around seamlessly with its own sound. The benefit is for a large collection, and even twenty-five quid DC locos off ebay (other auction sites are available) will work. The advice I need is on what slide potentiometers to use. Would they confuse or even wreck the chip?? Any advise gratefully received. Ron Ollerenshaw in France. PS the sketch was done before I came up with the idea of using jack plugs but hopefully you get the principal folks. Link to post Share on other sites More sharing options...
rodshaw Posted July 17, 2014 Share Posted July 17, 2014 What are you doing about short circuit protection for the decoders? Is it built in? Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 18, 2014 Share Posted July 18, 2014 I haven't taken any specific measures against short circuits, I'm just working on the basis that this is just really a re-hash of a chip-in-a-loco. I'm thinking that as all connections are done with stereo jack plugs, (power from the chip to the track sections, sound signal from the chip to a set of sliders), then there is no risk of (literally!) getting my wires crossed. If I'm missing something please let me know, I can't afford to melt a chip. Thinking about it, if a 6" nail fell on the track, it would be shorting the feed between the chip and the motor, rather than the feed between the DCC controller and the chip. Is that a particular problem? As far as my imagination takes me, circuit-wise that would appear to be the only difference from running a loco with a sound chip on board. Thanks for your interest, Ron Link to post Share on other sites More sharing options...
rodshaw Posted July 18, 2014 Share Posted July 18, 2014 All I know is I've been warned off this kind of setup by two different companies when sending specific enquiries to them. Digitrains: "I would not recommend powering your track from a decoder as a short on the railway, which will happen sooner or later, will kill the decoder. They are not designed to operate in this manner even though it seems at first sight that they will do this. The best solution is to have decoders in your locos where the motor outputs are protected and hidden away from track problems and use a cheaper sound only decoder such as an MRC diesel sounder (0001909) or one of the Digitrax SFX sound only decoders. These can then be operated in tandem with the locos you want the sound genererated for. Much more reliable." Soundtraxx: "You cannot use theTsunami's motor wires to send DC power to the track however. The Tsunamidoes not have any protections against short circuits and is not designed tobe used as such." But maybe your setup is different. Link to post Share on other sites More sharing options...
RMweb Gold colin penfold Posted July 18, 2014 RMweb Gold Share Posted July 18, 2014 So the inference from that seems to be that there is a greater chance of frying a chip in the proposed arrangement than if it's in the loco. Clearly any warranty would be void as it is operating other than in accordance with manufacturers advice. However, if it allows peple with a large DC fleet to operate sound with one chip per controller rather than one per loco, the figures probably still stack up. I await with interest the advice of more technically minded people as to how big that risk is. I'd also be interesred to know whether multiple loco classes can be represented on one sound chip, and if so, how many. Thanks to all the people contributing to this thread and trying to pioneer new methods for DC sound. Link to post Share on other sites More sharing options...
rodshaw Posted July 18, 2014 Share Posted July 18, 2014 As my posts imply, I've been tempted by Ron's kind of setup myself...all I need is a sound chip...now if Ron were brave enough to actually cause a short, see what happens and report back, then we'd all know! Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 19, 2014 Share Posted July 19, 2014 Original poster here ... I'm not surprised the manufacturers don't like this, they'll miss out on selling a lot of highly-priced chips. I started this discussion to try to find the right sort of slide potentiometers to fade sound at various locations, so if possible I'd like the discussion to head that way as well. On the subject of short circuits, I'm not using Tsunami so that doesn't affect me. (using Loksound).Also I'm sure I've seen somewhere that you can wire in some sort of short circuit protection, but I can't remember where I saw it, let alone how it can be done. If they can effect this at the miniature level it must be possible using clumsier components that can be fitted to a circuit on a baseboard. Some sort of diodes perhaps? Don't know. Regarding multiple loco classes on one chip, obviously you can run similar locos, especially with the same number and size of driving wheels. If you really are into authentic sounds you can still run a fleet of 7 merchant navies for one sound chip! I've had several different-loco whistle sounds loaded onto one chip, Jubilee, castle, etc. I can't see how the "automatic" sounds could be duplicated on one chip. Ron. PS If I fry a chip by accident I'll let you know, but unless I win the lottery I won't be doing it on purpose.. Link to post Share on other sites More sharing options...
cassey jones Posted July 19, 2014 Share Posted July 19, 2014 Original poster here ... I'm not surprised the manufacturers don't like this, they'll miss out on selling a lot of highly-priced chips. I started this discussion to try to find the right sort of slide potentiometers to fade sound at various locations, so if possible I'd like the discussion to head that way as well. On the subject of short circuits, I'm not using Tsunami so that doesn't affect me. (using Loksound).Also I'm sure I've seen somewhere that you can wire in some sort of short circuit protection, but I can't remember where I saw it, let alone how it can be done. If they can effect this at the miniature level it must be possible using clumsier components that can be fitted to a circuit on a baseboard. Some sort of diodes perhaps? Don't know. Regarding multiple loco classes on one chip, obviously you can run similar locos, especially with the same number and size of driving wheels. If you really are into authentic sounds you can still run a fleet of 7 merchant navies for one sound chip! I've had several different-loco whistle sounds loaded onto one chip, Jubilee, castle, etc. I can't see how the "automatic" sounds could be duplicated on one chip. Ron. PS If I fry a chip by accident I'll let you know, but unless I win the lottery I won't be doing it on purpose.. How can you run a fleet of 7 merchant navies from one sound chip? Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 19, 2014 Share Posted July 19, 2014 Not all at once, obviously. Just read the blog so far. Link to post Share on other sites More sharing options...
cassey jones Posted July 19, 2014 Share Posted July 19, 2014 Not all at once, obviously.read the blog so far. But if you did,you would need 7 sound chips? Might as well have in the loco's where they are meant to be. Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 20, 2014 Share Posted July 20, 2014 Not so. Again, please take the time to read what I've already written. Moving on, and on the subject of short circuit protection, I think the answer is simple. You just put a diode of suitable capacity on the -ve wire from the track to the chip. That would block any +ve current flowing from a short circuit back to the valuable chip. If anybody thinks this is inadequate please say. If it is adequate it shows how desperate the two manufacturers' responses set out by a previous respondent are. Bordering on the naughty, but you can't blame them. Anyway I'm glad this issue was flagged up, thank you. HOWEVER, nobody has come back with any help on my original question, i.e. what slide potentiometers would be suitable to fade the sound signal from the under-baseboard sound chip to strategically placed speakers. Ron Link to post Share on other sites More sharing options...
RandyWales Posted July 20, 2014 Share Posted July 20, 2014 .....shows how desperate the two manufacturers' responses set out by a previous respondent are. ....HOWEVER, nobody has come back with any help on my original question, i.e. what slide potentiometers would be suitable to fade the sound signal from the under-baseboard sound chip to strategically placed speakers. Hi Ron...I'm all for helping anyone who is trying to move ahead with cheaper sound, but electronics is not my forte, and it may be that others who have viewed your request for help also may not have the expertise... Please don't be discouraged by the lack of response, and please report back when you crack it... Randall Link to post Share on other sites More sharing options...
ZiderHead Posted July 20, 2014 Share Posted July 20, 2014 Since no one has picked up on this yet, Zimo sound samples are played as raw, uncompressed, lossless audio. Bluetooth audio is compressed and almost certainly very lossy, especially using those Veho units. Has anyone bothered to do a blind comparison of the same sample played by a decoder chip and bluetooth using the same speaker …? Link to post Share on other sites More sharing options...
RandyWales Posted July 20, 2014 Share Posted July 20, 2014 Since no one has picked up on this yet, Zimo sound samples are played as raw, uncompressed, lossless audio. Bluetooth audio is compressed and almost certainly very lossy, especially using those Veho units. Has anyone bothered to do a blind comparison of the same sample played by a decoder chip and bluetooth using the same speaker …? I can't really comment on the technicalities of audio systems as I don't have the background... What I can say is that I WILL be using 'those Veho units' for my 7mm fleet because, simply on cost grounds alone, there is no contest. To my ears, sample playback quality is better than anything I've heard from a sound decoder, and I am not constrained by chip capacity. Realistically, I very much doubt whether anyone is going to perform 'scientific' tests as suggested. I have played quality samples through the Veho module to a typical 4mm speaker and found that the 'tinny' sound normally associated with small decoder-fed speakers was far less evident. I am still bemused by the fact that people are willing to hail horrendously expensive sound decoder technology and frown at attempts to find a cheaper (and maybe better) alternative. Randall Link to post Share on other sites More sharing options...
ZiderHead Posted July 20, 2014 Share Posted July 20, 2014 I guess my point is that the sound quality depends on the source material and speaker design and installation. Your approach may be cheaper for some people, for some applications, and … fair play to you for exploring it I'll put my hand up as someone who is blown away that I can get a programmable polyphonic sampler on a tiny chip for just £50 more than a non-sound decoder, if you wanted that functionality in your recording studio in the late 80s the box was the size of a big PC and cost £30,000! Link to post Share on other sites More sharing options...
RandyWales Posted July 21, 2014 Share Posted July 21, 2014 I guess my point is that the sound quality depends on the source material and speaker design and installation. Your approach may be cheaper for some people, for some applications, and … fair play to you for exploring it I'll put my hand up as someone who is blown away that I can get a programmable polyphonic sampler on a tiny chip for just £50 more than a non-sound decoder, if you wanted that functionality in your recording studio in the late 80s the box was the size of a big PC and cost £30,000! At last, gracious and magnanimous response to this contrasting perspective on Model Railway sound....Thank you Ziderhead.... However, taking your analogy further, I maybe owe Apple £25million+ for my iPad if I was to compare it with the capabilities of the IBM mainframe computers I was working on during the same period. Conversely, Sound Decoders should now be selling for ten-a-penny. Randall Link to post Share on other sites More sharing options...
rodshaw Posted July 21, 2014 Share Posted July 21, 2014 Moving on, and on the subject of short circuit protection, I think the answer is simple. You just put a diode of suitable capacity on the -ve wire from the track to the chip. That would block any +ve current flowing from a short circuit back to the valuable chip. If anybody thinks this is inadequate please say. I'm not an electronics expert but I don't think it's that simple. A short would result not in current going the 'wrong' way but in the loco motor being bypassed, thereby drastically reducing the resistance and overloading the circuit. But I'd also like to know how it's done. It's obviously possible, as I believe some sound decoders do have the required protection. Link to post Share on other sites More sharing options...
Modelling Martin Posted July 21, 2014 Share Posted July 21, 2014 Sorry to divert the topic of conversation a little bit but i couldn't help noticing the Soundtraxx locomotives Bachmann were going to produce have been "cancelled from production" which i feel is a great shame. Just wondering whether anyone had any more information regarding this? Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 21, 2014 Share Posted July 21, 2014 Thanks for your input Rodshaw, but what you describe is the same thing as I'm talking about. If the motor is by-passed, so there is no resistance in the circuit, you are basically supplying +ve to both rails, feeding +ve from the motor output of the chip back into the motor input on the chip that is expecting 0 volts, but getting rammed with 12v and maximum current. It won't like this one little bit. A diode wired into the circuit in the right direction will block this return voltage, along with any, (indeed all) current i.e. it is basically switching the circuit down. I'm no expert either, but this, unless I am seriously misguided, is fairly simple. Once again thanks for the input. Ron. AGAIN PLEASE CAN ANYBODY HELP WITH MY SLIDE POTENTIOMETER QUESTION??? Link to post Share on other sites More sharing options...
Poulmarvezen Posted July 21, 2014 Share Posted July 21, 2014 More response to Rodshaw's comments. Yes, some decoders might have inbuilt protection, but the worry is that the motor circuit isn't protected, as they don't expect the motor circuit wires to be compromised, short as they are and tucked away in the loco. My system is creating a very long and exposed circuit that is certainly at risk, and which, thanks to previous comments, I am now aware of. Ron Link to post Share on other sites More sharing options...
scoomby Posted July 23, 2014 Share Posted July 23, 2014 Hi all. Hornby have a video of their soon to be released P2 with TTS sound: http://www.Hornby.com/news/the-lner-cock-o-the-north-p2-class-approaches/?utm_campaign=Hornby_Email_Issue114_205107&utm_medium=Email&utm_source=CM_hornby What do you think? Steve Link to post Share on other sites More sharing options...
clickertyclack Posted July 24, 2014 Share Posted July 24, 2014 Hi all. Hornby have a video of their soon to be released P2 with TTS sound: http://www.Hornby.com/news/the-lner-cock-o-the-north-p2-class-approaches/?utm_campaign=Hornby_Email_Issue114_205107&utm_medium=Email&utm_source=CM_hornby What do you think? Steve TTS.................Toy Train Sound cc Link to post Share on other sites More sharing options...
tender Posted July 24, 2014 Share Posted July 24, 2014 Since no one has picked up on this yet, Zimo sound samples are played as raw, uncompressed, lossless audio. Bluetooth audio is compressed and almost certainly very lossy, especially using those Veho units. Has anyone bothered to do a blind comparison of the same sample played by a decoder chip and bluetooth using the same speaker …? If we are talking the size of speaker that would fit in a loco then this would probably only tell you how good (or bad) the speaker is. If you want to compare the sound quality between a sample from a decoder chip and compare with a Bluetooth transmitted sample you really need to play them back through a decent sound reproduction system (Hi Fi). I have a QED Bluetooth system connected to my HiFi and the sound quality of MP3 music from my smartphone played back through this is remarkably good. Can't say the same playing the MP3 music back through the Veho Bluetooth device from the smartphone, but then what do you expect from a 30mm speaker in a 50mm plastic tube. When I get some spare time I'll try connecting up the output of a sound decoder to the HiFi, that should give a good indication of the quality of the recorded samples (and or the the internal sample playback system and amplifier). Link to post Share on other sites More sharing options...
RandyWales Posted October 11, 2014 Share Posted October 11, 2014 Hi again.... Just a quick update to let members know that Bachmann, no less, are introducing a Bluetooth Wireless Control system that also sends sounds to onboard speakers using Bluetooth. If Bachmann are developing alternatives, it must be because they recognise the fact that expensive licencing fees for DCC soundchips are eating into their profits. It is pretty crude at the moment, but maybe this is something that will make people sit up and take notice. I am already using quality samples through Bluetooth, and it sounds brilliant (and dirt cheap). http://resources.bachmanntrains.com/ihobby2014/html5/index.html?page=1 http://bluerailtrains.com/intro.cfm Thanks to Shortliner and others in the Continental/Overseas thread for keeping an eye on developements on other shores. Randall Link to post Share on other sites More sharing options...
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