Trailer Speaker Help
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Category: General
Forum Name: 12v Powered Systems
Forum Description: From Mini-rigs to ICE, all your low voltage audio needs here...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=97213
Printed Date: 23 April 2024 at 1:01pm
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Topic: Trailer Speaker Help
Posted By: ambientvoid
Subject: Trailer Speaker Help
Date Posted: 29 November 2016 at 11:48am
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apparently i posted this in the wrong place so until a mod can move the topic across here's a link: http://forum.speakerplans.com/topic97202_post972436.html#972436 i appreciate being pointed to educational materials but if someone could just tell me if these components work together that would be awesome, if these components don't work together please tell me what i need instead. i would prefer to keep the amplifiers as i made the mistake of already purchasing those. my main requirements are high volume/dispersion and low weight. whatever i end up with has to fit into an area measuring 36 inches long by 18 inches wide
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Replies:
Posted By: slaz
Date Posted: 29 November 2016 at 12:30pm
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The 8" bass driver you mentioned is hopeleeely inefficient ..... you would need about 16 of those to get anywhere near the efficiency of a 2" comp driver. I'd say get a plasic 8+1 mid-top speaker - something like a wharfedale titan 8 or ev sx80. This could mount on a rack above the rear wheel (the idea of this is to keep the trailer weight down). The build something like a 12" bandpass bass box to mount on the trailer - if using 15mm ply and (if poss) a suitable driver with neo magnet, should be possible to keep the trailer weight down to about 12-15Kg. But those max amp things are way underpowered .... won't get more than about 10-12W into 8R load. Consider a 4ch full-range class D car amplifier (e.g. Pioneer, Alpine) - this will get you something like 150-200W (by bridging the 4 channels into 2) into each of the bass box and mid-top, and you can use the amplifiers built-in filters as Xover. The amp couold (for example) be mounted on a handlebar "basket" type of arrangement. The problem then of course is the battery ..... reckon on about 6-7 Ah for each hour you want to play for (e.g. a 20Ah 12V battery would play for about 3 hours at full beans - alot longer if you reign in the volume a notch or 2. LiFePo4 would be great - but pretty expensive. Lead acid is much cheaper- but a good deal heavier. Another approach is to decide to limit the LF extension to about 70-80Hz or so, and just mount a pair of the above mid-tops on your trailer ..... then use a HP filter at 80Hz or so. Yet another approach (on the amp/battery side) is "go for the volts". Use a e-bike LiPo battery at 36V and get a 5630 chip-amp module. Advantage is better power efficiency .... but you'll have less than optimal impedance matching (most chip-amps are really designed for 4R loads). With a 5630 module (which is advertised as 2 x 300W) you'should get about 2 x 60W or so with 36V supply into 2 x 8R load. Its all about compromises in a way that mains-powered isn't (so much). ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 29 November 2016 at 1:31pm
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can i remove all the heavy crap off one of those car amplifiers and just use the board itself in a lightweight tin or something? is there an alternative amplifier similar in weight to the maxamp amplifiers? its not going on a bike, its going on a longboard/skateboard which is why it needs scaling down a bit but this also means everything needs to go on the trailer, do you think i could keep the overall weight down to around 20kgs? im all for purchasing a couple of dj type plastic speakers and strapping them down if that works. my previous speaker setup was just a pair of 6.5inch coaxial car speakers which sounded ok to me but was too quiet, im not super bothered about loads of bass its just that all the diy speaker systems iv ever seen have a huge sub/bass speaker somewhere on them so i figured thats what im supposed to have too... also if i just go for a couple of those wharfedale titan 8 or ev sx80 speakers do i still need a crossover or not?
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Posted By: slaz
Date Posted: 29 November 2016 at 2:32pm
A skateboard thingy ? Whoa - like it :-) Well its not impossible I suppose to remove the amplifier PCB from a car amp case, but I wouldn't recommend it unless you're able+willing to do a fair amount of DIY .... the case is the heatsink for the o/p trannies ..... doubt if you'd save much weight either, as the class D car amps don't usually have have great big chunks of ally for cases. Do you still have the 6.5" coaxial speakers built into a box ? Are they decent ones ? Built into the right kind of box ? If so, you might find just giving them a good clean 50W or so each will achieve what you want .... and thats quite do-able (assuming they're 4R impedance). I have a setup here along those lines (mine has 2 x old-skool JBL car 6x9) ..... with a Sure ST506 chip-amp module powered by a 6S (nominally about 24V) LiPo battery (which are normally used for RC models, drones etc.). The amp is built into a plastic constructor case, and the battery sits atop the speaker box for quick/easy swap-out. If using one of these amp modules, you'll likely need a line-driver/pre-amp of some sort if using a phone/ipod or some such as music source - which I imagine you would be. You'll need an appropriate LiPo charger and probably some bits+pieces of adapter cables etc. for the power, and there's a bit of wiring-type DIY to make the amplifier housing (you'll want power switch, volume control, voltmeter, connectors etc.) Also you'll need to learn a bit about how to treat LiPo batteries and get your head around the "computerised" charger a bit. If you're in the London area I could even show you around my setup I suppose ... bring your speaker box and some beer :-) and you could plug in to my amp/battery. Weight of my 6S 5Ah LiPo battery + amp is not much over 1Kg - and it plays full welly for about 4-5 hours, but I have extra batteries to play for longer - which can easily fit in a small rucksack/whatever. The whole lot (without speakers) i.e. amp module + box + bits for amp + 1 5Ah battery + connectors/adapters + charger + charger PSU could be had for around £150 I think. 2 of the Wharfedale Titan 8 would be better + louder, but would be bigger + heavier + cost more. If using the above amp setup, you'd only be getting about 30W into each speaker (as they're 8 ohms) but would still be louder than the car speakers. Oh yeah - if using existing car speakers or Titan 8 or similar small PA mid-top you would not need a crossover, as these have internal passive crossover. It would, however, benefit your battery-life (i.e. run-time) if you add a suitable HP filter (easier said than done). ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
ambientvoid wrote:Posted By: ambientvoid
Date Posted: 29 November 2016 at 10:55pm
 what is a plastic constructor case? i will be using an mp3 player source most of the time and occasionally my phone
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Posted By: ambientvoid
Date Posted: 30 November 2016 at 8:20pm
| i tried looking up the Sure ST506 chip-amp module and could only find an STA508, is it the same thing, maybe an updated version? is there another similar Sure amp i could use to push a bit more power through the Titan 8's? |
Posted By: slaz
Date Posted: 30 November 2016 at 9:45pm
Oh errrr .... yup ST506 was a typo - should have read ST508 ... sorry. Other chipsets you could use are 7498, TA5630 ..... what you'll get out (power-wsie) of those really just depends on the supply voltage. Sure electronics is a decent brand to go for - they tend to be a bit better built than most. BTW, the Titan 8 is not the only speaker to consider. I mentioned it because I've heard the Titan 12 - and I reckon it gives pretty good value and quality, and (the Titan 8) is pretty light in weight at 5.5Kg each. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 30 November 2016 at 10:37pm
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size wise i think i could fit a couple of Titan 12's on the trailer but i would probably only be able to fit one because they're more than twice the weight of the 8. im not sure if a single Titan 12 would be better or worse than two Titan 8's. i think now that i know im going down the route of strapping down pre-made speakers i'll go ahead and build the new trailer chassis and borrow some bags of sand or something so i can experiment and see how much weight it takes comfortably before it affects the handling. i called the DJKIT shop earlier and they're getting new stock in next week so they might have some 12's in too for me to check out... i admit im leaning towards the Titans for the very important reason that i think they're kind of good looking haha
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Posted By: bitSmasher
Date Posted: 01 December 2016 at 11:04am
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First things first, as you just mentioned... find out just how big/heavy a load you can roll on your board From there, work backward to build an "ideal" system around whatever compromises you have Just as important, what's your budget? And, you mentioned having speakers, charger and amplifier? Why don't you list everything you own currently, it may be usable Given you sound like your DIY skills could be a limiting factor, go with the idea of a prebuilt speaker The plastic Wharfdale is one option, and there'd be bunch similar for cheap on the second hand market. Don't need stereo for this project so a single speaker could work fine - especially if you go for a 10" or 12" woofer I wouldn't worry about a sub either, that'd really complicate things To set some realistic expectations, it's hard to make big bass outdoors... especially on the move Don't succumb to "project creep" where each revision gets bigger/complex/expensive, make some sound first then decide if you want to progress the idea Finally, read through the 12v forum, there are some great project threads... going back a few years, this is one of mine: http://forum.speakerplans.com/trike-proto-1_topic87200.html" rel="nofollow - http://forum.speakerplans.com/trike-proto-1_topic87200.html - I went for "brute force" with big heavy parts I had on hand, but could've easily achieved similar results with a smaller battery maxamp-style chip amp ------------- https://www.instagram.com/batteryacidsoundsystem/ |
Posted By: slaz
Date Posted: 01 December 2016 at 12:28pm
I agree that speakerwise - a single plastic speaker would be good, but .... Although there are plenty of chip-amp modules - some 1ch PBTL ones which are usually designed to deliver their optimum power into very low impedance loads like 2R. With a single 8R load, obviously much less o/p - e.g. a PBTL 5630 chip amp advertised as "600W" is into 2R load, and with maximum safe VCC. - so with e.g. 8R load and 36V supply this would be more like 120W - which would be great - but where does the 36V come from ? If you use say 24V supply from a 6S LiPo pack, o/p would be around 40-50W. One option (for 36V -ish) would be a 36V e-bike battery - which - with chrager - seems to be about £200. Another might be a RC-type LiPo 6S with a DC-DC up-converter - but the specs on these is usually pretty vague - and I'm not too sure about reliability with these. The jist of the problem with single 8R loads is getting the supply volts. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 02 December 2016 at 10:41am
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im not really sure on budget, the last mini system of 2 x 6.5's, battery and amp was about £200 so i think it would be safe to assume this system could end up being closer to £400 maybe? the only speakers i have already are a pair of 6.5 inch coaxial marine speakers to replace a pair of component 6.5's which don't seem to work anymore (though it could be the amp, i have nothing else to test them on). the old amp is an Amp6basic bought from the 41Hz shop several years ago, i purchased it but sent it to an aquaintance i met through a skate forum (and who i lost contact with after the forum went down) who had built lots of speaker packs for a skate club and he did all the tweaking and soldering before putting it in a case and giving it back to me as a plug and play unit (so i have no idea how to test or fix it). i have 2 chargers, one is a trickle charger for my SLA batteries and the other is a Turnigy Reaktor balance charger purchased for LiPo RC batteries but it can also charge LiIo, LiFe, NiCd, NiMH and SLA batteries if i get the appropriate connectors. the aquaintance who put the amp together for me did say something about bass getting lost outside and how it was a drain on the battery so i think he might have tweaked the amp somehow to reduce the bass output... considering that i won't have a bass/sub speaker and that the woofer will then be much lower to the ground would a wedge monitor speaker be a good idea to angle the sound up to head height rather than foot height of people following me?
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Posted By: ambientvoid
Date Posted: 14 December 2016 at 11:08pm
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ok so iv been looking at different 24v battery options and i found this battery: https://hobbyking.com/en_us/multistar-high-capacity-6s-20000mah-multi-rotor-lipo-pack.html" rel="nofollow - https://hobbyking.com/en_us/multistar-high-capacity-6s-20000mah-multi-rotor-lipo-pack.html and i have been looking at amps based on Slaz's suggestions and i found this Sure 2x100watt TK2050 amp: http://store.accusafe.nl/modules/versterkers/sure-2-x-100watt-class-d-audio-amplifier-board" rel="nofollow - http://store.accusafe.nl/modules/versterkers/sure-2-x-100watt-class-d-audio-amplifier-board for the battery given the danger of over-discharging lipo is there such a thing as a stand alone inline cutoff module for 6s batteries that could work in a speaker system setup? i've seen a few cutoff modules for smaller batteries but they all seem to rely on signals from an RC ESC unit to work...
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Posted By: slaz
Date Posted: 15 December 2016 at 1:00am
Well that amplifier will work fine at 24V - but with 8R loads you'll be getting about 2 x 30W or so - nowhere near 2 x 100W. With relatibely efficient PA speakers e.g. the 2 x titan 8 - it should be about the same volume as my bike box ... and will make for a pretty loud skateboard :-) But I think the battery is a bit oversized TBH. Should play for about 24 hours :-) Might be more sensible to get 5-6-7 Ah - which should play the whole day. I'd recommend building a voltmeter in somewhere (I built one into the amplifer with a momentary contact switch) - then just keep an eye on the voltage every now and then. Stay on yellow alert when the batt voltage gets down to about 22V, and stop using it at 21V. Conventional wisdom (at least in a commercial product that needs to be pretty much idiot-proof) says use a BMS circuit - but these can be quite troublesome. Do the work of the BMS manually. Don't let your charger charge up to 4.2V/cell .... the battery will last alot longer (in terms of charge cycles) r if you charge up to about 4.1V/cell - only sacrifices a few percent of capacity. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 15 December 2016 at 2:42am
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how would it perform on 1 x titan 12 speaker? assuming i ask around and manage to find a decent DC-DC up-converter to boost up to the max 32v for that amplifier what gets sacrificed to achieve that extra voltage? and what would that 32v do for the wattage? |
Posted By: slaz
Date Posted: 15 December 2016 at 12:50pm
Well the DC-DC up-converter is one way, yes, BUT .... Most DC-DC boards will draw a large current in-rush when you switch on/connect. Strange things can happen when its load is also connected ..... could e.g. blow the fuse between battery and load. ISTR Sure made one or two DC converters - which may well be better than most, albeit more expensive. The trade-off in using the DC boards is some loss of battery power - expect a real-world efficiency of about 80-90%. I have a car laptop power adapter rated at 120W and with a top o/p voltage of 24V (to cater some old Apple laptop that used 24V). This actually works fine for powering my ST508 amp from a 12V lead-acid battery. But there's another way to achieve your 30V plus .... as long as you're willing to learn about/understand Lithium cells a bit, know your way around your charger, and be willing to baby-sit the batteries during charge. Just get 2 4S packs and make a custom wiring loom that connects the packs in series for discharge, and lets you charge them individually (with your existing charger) by unplugging from the loom. Or you could, of course, just get a 8S battery pack, but then you'd probably have to get a charger that can deal with 8S .... I think Turningy makes one. This will achieve about 33V at top charge level - which should in turn get you about 70-80W into a single 8R load (such as 1 x titan 12) - and that should do nicely. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 15 December 2016 at 3:35pm
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I'm happy to do 2x 4s batteries, I've found one at half the capacity of the last battery i linked, I realise it's still more play time than I'd likely need but I'd rather have a bit more than I need instead of potentially less. Unless I'm missing something series wiring doesn't sound that complicated. Would something like this work, where the ends marked 'speed control' would go to the amp?  With maybe xt60 connectors instead of the ones in the picture I could easily disconnect and reconnect the batteries and charge them with my existing charging cable. |
Posted By: slaz
Date Posted: 15 December 2016 at 5:00pm
Yes exactly that (re the cabling). Just make sure you get the right gender of connectors and make solid connections. The charger will balance the cells within a pack, but you'll need to balance the 2 packs relative to each other manually - thats IMPORTANT ! Vital to distribute the load as equally as possible across the 8 cells. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 15 December 2016 at 5:04pm
| How do I go about balancing the packs to each other? |
Posted By: slaz
Date Posted: 15 December 2016 at 7:54pm
Well - you can of course just alow the charger to take the cells up to within 10-20 mV of 4.2 (i.e. "full"), in which case the 2 packs should be quite closely balanced ..... but I now stop charging when cell voltage reaches abut 4.1V/cell - this achieves considerably better long-term life for the batteries. (Thats a widely accepted policy ..... I also found this out the hard way :-/ ). In your case you'd need to manually monitor this - unless - see below :- One possible way is to tell the charger you have "Li-On" rather than LiPo - most chargers will then "aim for" 4.1V rather than 4.2V - haven't tried this myself - currently investigating this, as I'm not sure if there are any other differences in the charge cycle. If anyone in here has info on this - please do tell ! ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 16 December 2016 at 12:58pm
| Ah okay, but is there no way of ensuring that the power draw from each battery remains equal during use? |
Posted By: ambientvoid
Date Posted: 23 December 2016 at 12:08pm
| As I'll be using my mp3 player as the source will I need a pre-amp or mixer to boost the gain? Are there 24v - 30v pre - amps and if not how do I attach a 12v device into a 28.8v circuit? is there some way i can wire it in so that it is drawing from just one of the 14.4v batteries? |
Posted By: ambientvoid
Date Posted: 29 January 2017 at 3:53pm
My pile so far, im just waiting on the mixer (a gold Omnitronic Gnome-202 Mini) which should arrive sometime next week. In the end i decided that the easiest way of powering a mixer was to run it off separate batteries, the 2 red 12v packs in the picture below, i got a parallel harness for them which will give me a little over 5000mah capacity or about 8 hours run time which should be adequate for me in most circumstances. A couple of things im missing because im not sure which ones to get are an On/Off switch for the main circuit powering the amp, and a fuse. All DC power switches i've seen/used are rated for 12v but obviously this circuit is going to be about 30V to 32V when the batteries are fully charged so im not sure what power rated switch i'll need, an exactly 30/32V switch or something higher for the sake of safety? and i have no idea where id get a switch like that...? I have absolutely no idea on choosing fuses, i had a fuse in an inline fuse holder on my old 12V speaker but i just used what i was given and luckily it never blew
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Posted By: slaz
Date Posted: 30 January 2017 at 12:17am
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OK - well a coupla things .... That mixer says 12V DC 500mA on it .... but you may well find it actually uses a good deal less than that - its just that trhe supplied PSU is rated at 500mA. Not using the headphone amp will help with that also. Best to use a multimeter to measure its consumption while in real use, i.e. put signal into it, connect your load (amplifer) .... you well find it uses 200mA or less - in which case 1 of your batteries will power it for a whole day. No point in over-complicating things. Your switches - don't get too hung up on the ratings - most wil have 1 rating for 230V AC and anothe rfor 12v DC (which will be alot lower) ..... I think you'l find a switch rated at 5A 12V DC will be fine. Fuse - I'd use about 5A for your main 30V line. How you gonna build it all together ? The mixer seems like a bit unecessary TBH - although it should give you the gain you need, and likely the tone controls wil be useful. Which Sure amp module is that you have ? ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 30 January 2017 at 1:17am
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Good to know the mixer might last longer than i thought, i was a little concerned that it might run out before the amp but perhaps it'll be fine now. It might turn out to be unnecessary but id rather have it and not need it than need it and not have it... It'll be awesome if i can use a 12V switch, it'll make it much easier and cheaper to get (and replace if i ever need to). Thanks for the pointer on the fuse too, hopefully i should be able to pick that up and a switch in town next week. i plan to mount a lot of the small electronic bits into padded tupperware type containers screwed into the trailer, this should be especially useful for holding the batteries. im concerned about how to mount the amplifier module though as it has a fan cooler on top of a heatsink and i think putting it in a plastic box wouldn't be good for airflow. From what i've seen online some people mount amp modules in special metal pcb cases where the case acts like an extra large heatsink but i don't know how to do that myself...
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Posted By: studio45
Date Posted: 30 January 2017 at 3:45pm
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You will need some airflow for the amp. I guess you are worried about water ingress - there's 2 things to remember there: a) this is all low-voltage stuff, so the potential for sudden catastrophic failure is much less than with 230v AC flying about. The official acronym for <50v DC supplies is "SELV" for "Safe Extra Low Voltage". If you dropped your amp board in the canal while it was powered on, it would have a pretty good chance of survival, if you fished out out promptly. And you're never going to get a shock from voltage this low. b) How often are you really going to be playing out in the pouring rain without any cover? Not that often....12v systems are for when it's sunny ;) So you can cut some vents in the Tupperware without worrying. In my experience Sure amps run incredibly cool, and that fan will hardly ever come on. (Unless yours is one of the boards where it runs all the time, in which case you'll probably never see it run full speed.) Have you considered using a switchmode boost regulator at all? EG the Sure "boost regulator power supply" boards? Not necessarily to raise the voltage above 30v (although that might be beneficial) but for the other thing they do - hold their output voltage constant as the batteries on the input discharge. This, combined with good battery protection, means you will get 100% full power right down to the "flat" state, rather than a gradual loss of headroom as the rail droops. At the cost, of course, of a couple of % wasted power in the regulator itself. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: slaz
Date Posted: 30 January 2017 at 3:48pm
Erk .... whats the highest supply voltage rating for that amp ? I thought it was about 30V ? If using 2 x series 4s LiPo batts, your gonna have close to 34V at full charde of 4.2V/cell (or nearly 33V at 4.1V/cell). I'd have gone for the Sure 5630 module .... ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 30 January 2017 at 4:37pm
just had a thought, could i mount the amp board upside down in a tupperware box vented on the bottom with a gap underneath? that way it should further reduce the chance of water ingress if i am caught out in rain...
it is 30V max. im a bit confused now because it says 14.8V on the side of each battery so surely that would be 29.6V for 2 batteries?
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Posted By: ambientvoid
Date Posted: 30 January 2017 at 6:36pm
| ok so apparently the voltage on the battery is nominal voltage (why they can't put the max safe voltage i don't know...), so would it be safe to combine a 3s battery in series with one of my 4s batteries to make 7s and therefore 29.4V? |
Posted By: slaz
Date Posted: 31 January 2017 at 2:57pm
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Well you _could_ change one of the 4S packs for a 3S one - if the cell capacity is the same .... BUT - you _might_ be OK using the 2 x 4S packs - especially if you charge to 4.1V/cell rather than 4.2V/cell - would be less than a volt over 32V - and this voltage would drop very quickly to below 32V. I think I'd be inclined to risk it. Thing about these chip-amps is - often they just paste in the chip specs as if they were the specs of the assembled module, when in fact other factors can come into it. One thing to check, for instance, is the voltage rating of the capacitors on the board. For a 2050 board, some of the cheapest boards will use 35V caps- i.e. _just about_ in spec, but too close for comfort really. Hopefully the Sure ones might use 50V or 63V caps. Fairly sure I've seen - somewhere - specs of 2050 chip as max Vcc of 36V ..... ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 31 January 2017 at 3:39pm
i just checked and the 6 big caps down the sides are 63V, there are 5 smaller caps on the front of the board near the inputs that are rated as 25v though so i don't know if that makes a difference...
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Posted By: slaz
Date Posted: 31 January 2017 at 4:11pm
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OK well you won't have a problem with the smoothing caps (the 6 big ones) and any others won't be across the main power supply rails. As you're only using one channel of that amp, and its loaded with 8R, you'll be using only about 30% of its capacity - so shouldn't be any thermal problems. I reckon you'll be OK with 2 x 4S packs .... (but don't blame me guv :-) ) ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 31 January 2017 at 4:37pm
| what sort of impact would it have if i put a couple of 40w 4ohm speakers on the other channel? |
Posted By: slaz
Date Posted: 31 January 2017 at 5:32pm
Well don't put em in parallel - series will be 8R load so OK. It'll nearly double your power consumption, so obviously it'll shorten the battery run-time. Depending on what kind of speakers, where/how you mount/use them - well it might sound OK I suppose, but it could well also wind up sounding "messy" .... I'd fit an extra o/p socket for the spare channel - so if you get/borrow/hire another Titan 12 you can ramp it up a bit. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 31 January 2017 at 6:16pm
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right probably won't do that then, mostly just wondering as iv got a couple of 6.5" marine speakers spare now and i'll have at least a foot or so of empty space forward of the rear facing Titan 12... i like the idea of mounting a spare socket, one idea i had was to make something like a luggage rack for the front half of the trailer so that could be ideal for strapping a spare speaker to when im not carrying a picnic basket or something haha.
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Posted By: slaz
Date Posted: 31 January 2017 at 8:22pm
Sounds like enough space for a good few beers :-) The marine speakers will likely be pretty low efficiency - ain't gonna do much for your sound. Use em for another box/project. ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: ambientvoid
Date Posted: 01 February 2017 at 9:16am
| i had another look at the sure tk2050 user manual link on parts express (weirdly i didn't get a paper copy with my amp) to double check the max voltage and it seems to list two maximum voltages, in the Electrical Characteristics section it says the max input voltage is 30V but in the Overview section it says it can be powered by "any DC power supply ranging from +10 to 36V, which can be used to drive any 4ohm or 8ohm passive speakers". so that's confusing... |
Posted By: ambientvoid
Date Posted: 01 February 2017 at 9:23am
| also in the introduction Notes section it says it recommends DC36V to power it for 1 hour, so it's possible that the 30V max is for continuous usage in which case is it possible that 32 to 33V would be ok for a few hours at a time? |
Posted By: slaz
Date Posted: 01 February 2017 at 11:41am
Hmm ... bit strange .... but if that amp _were_ to go bang or phut - that gives you a very good case for getting a warranty replacement ! Likely as not it'll relate to thermal design - which, like I said - shouldn't be an issue for you when using 8R loads (less o/p current than 4R)). ------------- REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON |
Posted By: studio45
Date Posted: 03 February 2017 at 2:38pm
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I think all the chips Sure use have pretty good over-voltage protection. The chip will just not start up if the supply rail is too high. At least that is the theory. You should just get a red "SHDN (shutdown)" light and no output. Similarly, the chip can withstand and switch 36v safely, but not into 4 ohms indefinitely - at some point it, or the output filter, will overheat. Then you have to power-cycle it to restore operation, or repair the filter. Sure don't want people to encounter that "error condition", so they recommend a lower voltage. Srsly tho how about a regulator board. Then you can choose the voltage, and even use different batteries in future. You won't regret it ;) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: ambientvoid
Date Posted: 03 February 2017 at 11:23pm
good to know it potentially has that sort of auto cut off type safety feature, i was a bit worried that i might wreck the amp somehow if the voltage was too high. so as its going into an 8ohm speaker is it more or less likely to be able to handle up to 36V safely for an extended period? it won't have more than 33.6V going into it from my batteries anyway (32.8V if i manage to set up my charger properly), and if i understand it correctly that voltage should drop a bit more maybe an hour later...
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Posted By: studio45
Date Posted: 09 February 2017 at 3:47pm
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Yes, as far as I can tell it will run at 36v into 8 ohms indefinitely. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: ambientvoid
Date Posted: 26 February 2017 at 11:11am
| i've got the last few components now and i'm getting ready to start putting it all together but i've been looking at abs project cases to mount the components into but not finding anything of a useful size, cases are either too small to fit the amps width or way too large overall. so i was wondering if getting a slim hard case briefcase and drilling some ventilation holes in the side would work? i think i could make a hole to mount the power switch through. also i was looking at the chunky foam dividers in flight cases and wondering if they would be safe to hold the batteries in place while they're powered up or if there would be too much heat buildup? |
Posted By: studio45
Date Posted: 02 March 2017 at 7:37pm
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Sure a small briefcase is a good idea. I used the plastic cases that came with a pair of cheap large diaphragm condenser mics for the first iteration of my system. There was just enough space inside for all the boards, and they were very lightweight. Plus the carrying handle was useful for strapping them down to the trailer. I wouldn't worry about heat buildup in the batteries too much. Remember the 1/8th rule for audio power draw: your average long term power draw (averaged over several minutes) is only about 12.5% of whatever your highest peak draw is. Whereas for things like RC vehicles, the power draw is much higher and more constant. So your batteries are unlikely to get more than slightly warm, even if you run at full beans till they're flat. EG if you needed peaks of 15A, your average draw would be about 2A. This rule of thumb was more reliable before the advent of genres like dubstep and digital steppas, which can produce a higher average draw due to the more or less continuous high level basslines. But the figure is still likely to be no more than 25% of peak. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: ambientvoid
Date Posted: 04 March 2017 at 1:26pm
was that similar to the pelican cases/flight cases used for photographic and other audio equipment?
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