I know that this post / topic is a little unorthodox for this forum, but I guess I'll just see how you guys handle it......

I basically am going to create a small soundsystem, or 'boombox' for the summer. I am currently doing my A2 finals, and would like to have a system ready for the end of them - ie the summer! I am thinking a sub 10kg box with plenty of power that can run well for an afternoon, and cost under £200 (!)

So, I thought car stereo system (amp + equaliser + linein + radio in one) with a 12v deep cycle battery, and 6" car speakers. Here are what I have found so far:

VIBE SEK60 speakers  http://www.bassjunkies.com/audio/vibe-sek60-v3 - http://www.bassjunkies.com/audio/vibe-sek60-v3

Pioneer DEH 112e head unit  http://www.bassjunkies.com/audio/pioneer-deh-112e - http://www.bassjunkies.com/audio/pioneer-deh-112e

YUASA NPC17-12 battery  http://www.thebatteryshop.co.uk/yuasa-npc17-12-308-p.asp - http://www.thebatteryshop.co.uk/yuasa-npc17-12-308-p.asp

The SEK60s handle 115w RMS, so I would bridge the rear and front from the amp (4x55wrms per channel) to deliver more power to them. The battery while quite heavy holds alot of juice and can deliver it over a long time :-)

These would all be in a plywood box covered over with some speaker felt for a quality feel / construction.

Thoughts? Is there a better way of doing it? I know that car head units arent very efficient.....

Thanks all 

Can you give me a link to the topic? Thanks alot for the help

Is there a good site you could recommend for buying speaker components? For a good pair of sensitive speakers with tweeters (+ a little crossover) ?

thanks 

The eminence beta 8a - are they the standard beta 8s? Or is there a difference? Thanks for the advice, I would never have thought a 15w amp would have been possible to drive 8"s and tweeters 0.o.

I found 41hz, and was looking at the AMP1 packages - but then it started getting technical with the power supply needed and i began to doubt if it was worth figuring out all the electrics... That ebay link looks brilliant, and so cheap!

I think I'll go with a bigger battery tbh, not to keen on buying AAs, they seem to cost far too much in comparison, and a battery that will run all day is pretty tempting :).

I'm starting to be tempted to build a second module as well, the same amp but running twin subs to put underneath it to reinforce the lowend, but thats probably just me going over the top lol :).

i have been building a rig for my brother.  itll be complete by the weekend and i will post up picks of the build.  his budget was £200 total.

 

it consists:

4x 8inch bass/mids

1x 5.5inch mid

1x piezo tweeter

 

running from a sony 100watt amp (bridged)

batteries: 3x 7ah yuasa = 21ah. 

 

the cabinet is designed so it can be dragged on two wheels in the same way most modern suitcases are designed. 

Well, I guess when I get around to actually making the thing (2 months tops, I think im being a little premature..) Ill try it with one, and if it doesnt have enough kick, then I'll try running it with two ^_^.

After all £18 is pretty cheap- so I havent really got anything to lose, if I dont use the second then ill whack it in somewhere else :).

 

have a look on ebay for crossovers in the in car entertinment section.   im using a caliber half din unit.  its the same width as a head unit, but half the height.  nice little box with a preamp, 5 band eq, subwoofer volume etc., only negative is the fixed crossover points which im gonna be modifying to different frequencies if i can work out how.  try and find one with a variable crossover.  £20 should get you something more than adaquate.

So far I'm thinking a Yuasa 17Ah (smallest SLA deep cycle battery I can find, would use smaller ones in parallel if I could...) or 2 17Ah if I can find the cash.. This would then perhaps feed into a 1F cap (will 'loan' it from maplins to see if it works well enough, if not then ill package it up and return it). Then they go to the 12v equaliser and the 2x15w amp (which if it doesnt do the job then ill buy another and run one per channel). each these will then feed into a beta 8 and APT80 (1 of each per chan) via a little passive Xover..

Battery(s) -> Cap(?) -> 12v equaliser -> amp(s) -> passive Xover -> speakers

How does that sound?

SamV - MikeHunt79 reckoned earlier in this thread that they would be up to it? It is a pretty sensitive after all @ 97db 1w1m

 

i have used some pnuematic tyres. the ones that come on sack trucks.  i have also ripped apart my budget sack truck and used the handle and mounted it directly onto the cabinet.  its getting very heavy so i hope it wont be too hard to move around.  i wanted a one box system because previously i have had to transport battery, amplifier, cabinet etc separately.  previously the cabinet with the battery mounted within was too heavy for the sack truck i had.  now i have removed the weak points the scak truck exhibited i think it will be rigid and resilient.  also, with the battery and amps permenantly mounted and wired inside the cabinet i wont have to worry about damage to things like connections.  will post picks once thigs come together more coherently

 

http://cgi.ebay.co.uk/New-Mini-2-Channel-T-Amp-Class-T-Power-Amplifier-Amp_W0QQitemZ380116991159QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380116991159&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 - http://cgi.ebay.co.uk/New-Mini-2-Channel-T-Amp-Class-T-Power-Amplifier-Amp_W0QQitemZ380116991159QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380116991159&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280332500188QQssPageNameZMERC_VI_RCRX_Pr4_PcY_BID_Stores_IT&refitem=370187076431&itemcount=4&refwidgetloc=active_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget&_trksid=p284.m184&_trkparms=algo%3DCRX%26its%3DS%252BI%252BSS%26itu%3DISS%252BUCI%252BSI%26otn%3D4 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280332500188QQssPageNameZMERC_VI_RCRX_Pr4_PcY_BID_Stores_IT&refitem=370187076431&itemcount=4&refwidgetloc=active_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget&_trksid=p284.m184&_trkparms=algo%3DCRX%26its%3DS%252BI%252BSS%26itu%3DISS%252BUCI%252BSI%26otn%3D4

or this for £5 that has a "Aluminum alloy case good for sinking heat !" 

 

no way this will do 2x 75w, but even if it does 2x 10w rms itll be great because it looks like it has a high and low pass filter.  wonder if it is bridgable...  if so, one bridged low pass on a 8", and another stereo high passed on some mid+piezos:) 

Come summer i'm going to be building a single 12v powered cab using bits i have at home and stuff off ebay.

I have 2 Delta 15-LF and 2 1" comps currently.

In WinISD i did some fiddling and will likely use a 125l box tuned to 42hz to accomodate a single delta 15lf.

For the mid i reckon i'll use a sealed back driver (or two) like the Alpha8MR and then the 1" for top, adjusting the size of the cab for the amount of space the mid, top and batteries will consume.

 

I'd prefer to run it active with settings as follows:

50-60hz hi pass filter and ~500hz low pass on the bass

~500hz hi pass on the mids and configure the low pass crossover in accordance with the 1".

 

I'm thinking that a 1" with a single 15 and two 8" might be a little too much, but if it's run active it'll be an easy problem to solve.

 

Build will be using the lightest but strongest wood, so 12mm ply or mdf i imagine with loads of bracing. Really want to keep it as light as possible.

 

Then an amp to suit. Hopefully something with 4 channels, so 2 bridged for bass then another each for mid and tops.

 

Will also have to look into batteries, don't want over kill so something that can be used for like 8 hours at max. with a more likely run time of about 4-6 hours.

 

i'm yet to figure it out, but with the bigger batteries (i.e. bigger than rc ni-cad batteries) how do you charge them up? would something like a car battery charger work? mainly cos i have one of those to hand and would prefer to not buy a new charger.

 

I'll be using for similar reasons to everyone else, small gatherings with friends in woods, at beach. but also to hopefully be able to go into the city set up on some grassland and blast out some tunes and ting.

 

I'll post pics up over time. And give details of the build with any problems i had.

just put the wheel system in place on my main cabinet.  i was very worried the weight would be too much.  it certainly weighs too much to carry, but once put on its corner and rolled, it is easypeasie.  i have also included a pic of the bass driver for scale (18").  you can see the water proof coating i have applied to the cone to allow easy use in mild drizzle conditions.  should come in at around 75-90kg if my calculations are correct...

 

 

 

http://cgi.ebay.co.uk/LEISURE-BATTERY-YUASA-12V-65AH-NPL65-12IFR_W0QQitemZ400040826039QQcmdZViewItemQQptZUK_Campervan_Caravan_Accessories?hash=item400040826039&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 - http://cgi.ebay.co.uk/LEISURE-BATTERY-YUASA-12V-65AH-NPL65-12IFR_W0QQitemZ400040826039QQcmdZViewItemQQptZUK_Campervan_Caravan_Accessories?hash=item400040826039&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

 

65ah for £30 delivered cant be bad.  gonna need a 1 farad power cap due to limited current draw capabilities, but a 300w car amp will run well off this...

 

i know my battery (a ups style - not deep high discharge rate) struggles to deliver the current my amplifier wants-it is trying to draw up to 40-60amps @ 8ohm i imagine..  then again, a 12v class d amp will draw half what my a/b amp is pulling for the same power output and probably wont need a cap.  i intend on adding a cap to my power system to cut the stresses im putting on the battery and to also give me a quicker and less resistive supply to the amp when the kicks suck energy.  i can visably see the power led dimming on very high volumes and clipping occcurs earlier than it should.

 

with a car wet cell or deep cycle/cranking battery a cap wont make much difference other than cutting down on headlight dimming when the kicks hit..  if you check specs on this 65ah for £30, it has quite a high internal resistance meaning significantly less cranking output than a similarly sized battery designed specifically for high current delivery.

 

im pretty sure this £30 65ah battery will deliver more than enough for the average duty.  and imo adding a £25 cap should mean you end up with a cost effective setup that will compete against a high current battery costing around £100-150. 

The question is; what does their 500w translate to in RMS?  50wrms x 2 maybe?

Looks like you can make money from ebaying these :). Have asked the buyer for details on the batt, drivers and amp 

and thats £210 for all that..

 

just to let you all know that this weekend i'll be commencing the build of my first ever 12volt system.

I'll be using a delta 15lf run from 50-60hz to 500hz, an alpha 8 mr from 500 to 2.5k and a 1" comp from 2.5k onwards using a 3 way passive eminence crossover.

 

i'm yet to buy the amp or battery but i'm looking to get a 3-400w ish monoblock thing. and a battery  that'll last 5hours.

 

could anybody advise me on what type of battery i'll need, would 17ah last a decent amount of time?

 

will have pictures up sometime next week.

Got some spare cash the other day, so bought myself a little tripath amp. Got a true 20wrms per channel and was meant to be fairly expensive. (£80+). Thanks to the wonders of ebay and alot of luck I got it for £32 inc. p&p :D

Here it is driving me missions (cheap on ebay cos they didnt have grills  ). Anyways, it really does pump out 20w p/c. These missions are 84 spl w/m sensitivity, so with some eminence betas (96 spl w/m) my guess is it'll be pretty damn loud. (It still quite happily overpowers the missions..) You can get decent tripath ones pretty cheap - i would get one with bass / treble knobs though if I were you....

 

http://cgi.ebay.co.uk/New-Mini-2-Channel-T-Amp-Class-T-Power-Amplifier-Amp_W0QQitemZ380116991159QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380116991159&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 - http://cgi.ebay.co.uk/New-Mini-2-Channel-T-Amp-Class-T-Power-Amplifier-Amp_W0QQitemZ380116991159QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380116991159&_trksid=p3286.c0.m14&_trkparms=72%3A1690%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

 

To me it makes more sense to use two 12V batteries in series. Power goes with the square of voltage so you can get about 4x as much.

 

 

These are on eBay all the time for reasonable money (under USD$40 with shipping)

 

http://www.sureelectronics.net/goods.php?id=920 - http://www.sureelectronics.net/goods.php?id=920

I think bi-amping was mentioned earlier - think thats maybe the best direction? Setting the volume on the HF and LF amps to balance it out roughly, with an active Xover feeding into them the right frequencies.. (and EQing it all)

that way would also cut out the passive Xovers and Lpads :)

 

The bigger amps will run on anything from 10V~36V (of course the power depends on the voltage you use) . The small one is 12V only, and is currently USD$14.

 

http://www.sureelectronics.net/goods.php?id=12 - http://www.sureelectronics.net/goods.php?id=12

 

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grinner:  go onto ebay and search 'crossover' in 'in car entertainment'.  plenty pop up on there. 

 

http://www.youtube.com/watch?v=pjo_LKo7w7A - http://www.youtube.com/watch?v=pjo_LKo7w7A

 

check out this sure beauty:

http://www.sureelectronics.net/goods.php?id=918 - http://www.sureelectronics.net/goods.php?id=918

was kinda hidden on their site, but gives 100wrms per chan instead of 50.. mmmm 

 

At 4R it is capable of about 70W before clipping, maybe 40W/8R. The 100W/4R rating is at 10% THD.

 

 

Wilson?

Oh, and proper stupid question here:

I know that those amps can't be bridged, but would combining two of the amps as shown work, and how well? shown only 1 channel of each, but channel 2 would work the same.....

AMP1                                                           AMP2

                                    speaker +

                                       |

channel 1 + >>>>>>>>|<<<<<<<<< + channel 1

channel 1 -  >>>>>>>>|<<<<<<<<< -   channel 1

                                       |

 

the beta 8's will be loud with 5 true watts of power into them, 20wrms will be fine..  all depends what you require.  you wont get much bass from the beta's.  why not use a few drivers? like some of the skytronic 8" drivers i used for my bro's rig?  way cheaper than eminences, and pretty much the same thing.

id tune a double 8" box to 60/80hz and apply a 60hz high pass to cut down on wasted power and excursion.  id then run the pair of woofers off one side of the amp, and a pair of softdome tweeters off the other side (each channel will see a 4ohm load thatway).  remember that you will want to look for active crossovers with above 12db/oct.  a half din unit is nice if it has a volume knob and eq adjustment because it gives you a preamp to boost the pitiful output from an ipod etc.     

gonna have a think about it over the next few weeks, the exams finish on the weekend of the 20th, so ill get making it asap after that :)

 ?

 

tune the cab to 60hz and the woofers will kick out a racket.  the skytronic 3 way crossovers should work well with this config.  crossover freq's are 800hz and 5khz.  though if you are going active crossovers, id cross to the 6" drivers at 400hz to give them more work (they are more efficient than the 8" ones in the prominant midrange.  are the 6" drivers closed back?   

The 6" Fanes are open back I guess (in that you can see the cone through the basket??), but on blue aran they say that it can either be run full range if its ported, or mid only if its in a small sealed box.. I guess I'll decide how to run them once I've made the box - I'll then try out different ways of doing it.

amp-wise, im thinking for 2*50 for high, 2*50 for mid, with 2*100 for the 8" .. Would this work out about right? I'm unsure how much juice the tweeters would need to keep up with the rest it though - could 2*15 be enough? (These are all the sure amps btw). would all be wired up in parallel to keep pd constant 

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=250396016902 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=250396016902  

 

having a low pass of 400hz would work well with your 8" woofers too.

 

I think you should go for a 2x100 for the 8" woofers, and a 2x50 for the 6"+apt's, but run the apt's with a passive 2-4k crossover.  once you have them all set up, just pad the apt if its a bit too loud for the rest?

 

 

pretty sure I'll go with that plan then, once I get this thing up and running should blow away all those other sh*tty portable boomboxs on the market 

 

http://cgi.ebay.co.uk/2-100-watt-4ohm-TK2050-Class-D-Audio-Amplifier-Board_W0QQitemZ250439095410QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a4f555472&_trksid=p4634.c0.m14.l1262&_trkparms=%7C301%3A1%7C293%3A1%7C294%3A30 - http://cgi.ebay.co.uk/2-100-watt-4ohm-TK2050-Class-D-Audio-Amplifier-Board_W0QQitemZ250439095410QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a4f555472&_trksid=p4634.c0.m14.l1262&_trkparms=%7C301%3A1%7C293%3A1%7C294%3A30

 

if so, assuming i give it a 24volt dc supply, what sort of real world rms power are we talking into a 4r load?   and what sort of current draw are we talking @24volts? 

 

also, is this a plug and play device?  or do i need to supply my own heatsinking?

 

The Sure 100W amplifier will clip at 70W/4R with a 36V supply, about 40W/4R with 24V.

 

With both channels driven at clipping with 4R/24V the peak supply current will be about 12A. On 50% duty cycle program material  (sine-sweep bass) I would say about 6A RMS.

 

The Sure amps are ready to play. They come with a little heatsink that would benifit from a fan if you plan to pound it hard. Others have installed bigger heatsinks. 

 

http://www.diyaudio.com/forums/showthread.php?s=5769114bfaee3b16600c0c945690d257&threadid=143669&perpage=25&pagenumber=4 - http://www.diyaudio.com/forums/showthread.php?s=5769114bfaee3b16600c0c945690d257&threadid=143669&perpage=25&pagenumber=4

 

 

just picked up a pair of dvc woofers with 4r coils.  gonna run each woofer off one of these sure amps.  one coil per channel.  starting to look as if the system is gonna be very lightweight compared to my current setup:) ill only need 12ah compared to 90ah for similar volume/running times!

 

thanks for the detailed description.  very helpful mate

If only I had the cash 

36v, 15AH Lithium Battery....

(same capacity as a 45AH 12v battery)

 

the lipo you linked is probably half the weight of the nickel one i been working on...  im imagining a battery of this type might be sub £100 in a couple of years.. 

but then again, it is the most cost-effective way by far ...

 

you just persuaded me to pop onto ebay and search for some laptop batts..

i just won a job lot of 10 laptop batteries.  10.8v, 4400mah, li-ion..

 

i worked out that if each cell is 3.6 volt, ill have 3 cells per battery (or three pairs of parallel cells).

so total should give me 36volt @ 13ah if i run 3 parallel sets of 10 cells in series.

 

i won the auction for the starting bid of £4 and delivery of £12..  so a total of £16 delivered!

 

so mike, please could you give any pointers to successful removal of cells from packs, rewiring and charging tips? and any other advise you might have learned? 

for charging i been thinking maybe using tamiya remote control car battery connectors and making a few 10.8v packs to link in series during use, and charging each pack seperately at 10.8v from a laptop charger...  any views?