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Speaker amp size? Answered

Ok Im making a speaker, I´ve got 3 speakers connected in parallel and I want to buy an amplifier from Maplin. What kind of amplifier should I buy?
Speakers:
3W+3W+5W=11W
My multimeter says theyre 2 Ohms but thats because theyre connected in parallel really they are
4Ohm+4Ohm+8Ohm

So basically could someone tell me which amplifier to buy (it doesnt matter if its a DIY kit)

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kacper00100 (author)2009-02-07

Ok, thanks guys for all your helpful comments, today I went to Maplin and bought a 7W amp, but sadly they didn´t have any crossovers =( but I have one last question:
Does the crossover go before or after the amp?

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11010010110 (author)kacper001002009-02-07

if you use 1 amp for all speakers you have no choice if you use few amps then whatever you want (try both places)

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kacper00100 (author)110100101102009-02-09

What do you mean I have no choice?

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11010010110 (author)kacper001002009-02-09

a crossover splits 1 link into few if you use 1 amp you can place it only after the amp on the way to the speakers

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kacper00100 (author)2009-02-05

Ok I found two 40w speakers in the loft would a 200w (http://www.maplin.co.uk/Module.aspx?ModuleNo=46467) amp be ok for that or would I have to get something closer to 80w lol?

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Lurch (author)kacper001002009-02-05

Erm, bit OTT! I was thinking that was a typo, 20W would be better. Look at Quasar and ESR for more kits at better prices, Maplin is hopeless except for emergencies.

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kacper00100 (author)Lurch2009-02-05

lol no its because maplin has amps up to like 30w and then the next one is 200w lol and i want my music louder rather than quieter

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kacper00100 (author)kacper001002009-02-05

sorry for double posting but what is the difference between RMS and normal

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11010010110 (author)kacper001002009-02-05

RMS = the average power the speakers accept. it determines the max volume you can play on them

Peak = the max power they can get without distortion. it determines quality of beats and such

PMPO = to be ignored

you can wire the speakers 3 W + 3 W in series and that in parallel to 5 W. the 5 W speaker gets 5 W and the 3 W speakers get 2.5 W each. together you need 10 W RMS amp that can work with 4 ohm speaker

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kacper00100 (author)110100101102009-02-05

Ok so if I used this with the setup mentioned above and a full 18v will that be fairly loud for a subwoofer?

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11010010110 (author)kacper001002009-02-05

it can drive about 10 W rms with big cooler (way bigger than the one in their img). it is ok to drive those speakers. it works well on 12 V too (up to some volume) and works (not too good quality) on 5 V TDA2003 (this one) and TDA2002 (a bit less powerful variant) are very handy. i have some 2002s and use them quite often. buy it. at most youll connect it to one speaker and buy another one for the other. at the very most youll find another use to it unwanted hi-fi / lo-fi effects on this amp may occur and are easy to fix quality of basses depends on speakers more than amp. any speaker will shake walls with enough power. not any one will make it sound good

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Lurch (author)kacper001002009-02-05

Sure there'll be a Wiki on it. Basically RMS is the sustained power you can run a device at, the non-RMS number is often higher and is peak max, so really completely meaningless in specs.

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Lurch (author)kacper001002009-02-05

Doesn;t work like that. If the speakers are 40W then feeding 30W into them is about right. Shoving 200W in doesn;t make them louder, it makes them explode, so really loud for a brief second I suppose, but not really the desired effect. If you want loud you need decent speakers to match the amp, and it's also about quality. I could set up 500W of crap amps and speakers and have them outperformed by a decent 150W speaker and amp.

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Lurch (author)2009-02-02

I'd be inclined to not mix and match impedances and ratings in one package, although for that sort of size I wouldn't be expecting hi-fi listening pleasure. TBH pretty much any amp will suffice FWIW.

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kacper00100 (author)Lurch2009-02-03

Ye I know, Im just doing this as an experiment to see if it works lol, I might put some cool blue LEDs inside that synch with music too

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