diy 2.1 pc speaker

Discussion in 'The Projects Forum' started by juggler73, May 13, 2010.

  1. juggler73

    Thread Starter Member

    Apr 10, 2010
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    hi
    i got a old 5.1 home theatre system and i wanna recycle it into a 2.1 Pc speaker set.

    well i took it apart and found that it has 5x TDA2003 and 1x TDA2030A and couple 7805, 7812 regulators a toroidal tranformer and loads of capacitors and resistors loads of other stuff.
    also one 6" woofer and 5 small speakers.
    so i was looking up the schematics on the amplifiers and found that they could easily be used for a 2.1 speaker setup

    so i was thinking that i could use 4 Tda2003's, 2 bridged for left and 2 bridged for right and the Tda2030a for the woofer.
    i just need help connecting it up with the power and how to have the woofer for the bass.

    thanks
     
  2. Audioguru

    New Member

    Dec 20, 2007
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    I talked about your ideas on another website but I can't remember which one.
     
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    It's quite simple and you are on the right track.
    Do you have the volume controls and the crossover filters if any
     
  4. R!f@@

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    Apr 2, 2009
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    So post what you have and what you did. We need something to begin with
     
  5. juggler73

    Thread Starter Member

    Apr 10, 2010
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    well the TDA2003 dont bridge that well so im going for the TDA7240A for the two amplifiers. and the tda2030a for the woofer

    im stuck of the active crossover circuit ive looked and they all seem over my head. and how to connect to the speakers, does the woofer connect to one channel or both

    also the connecting of the transfromer to the whole thing, but ive got the pic for the bridge rectifier bit

    im going to connect 2 speaker in parallel which think the speaker are 4ohms each.
    Subwoofer output power 35 watt RMS
    Output Power 5 x 7 watt RMS

    thanks
     
  6. Audioguru

    New Member

    Dec 20, 2007
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    Like I said on the other website, the cheap little 3" speakers have maybe only 4.3W each. A little more power than a cheap clock radio that also uses a 3" speaker.

    But you show a bridged amplifier IC that might blow them up with 14W or more.
     
  7. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Yeah.. those speakers won't produce much and they are full range.
    For active crossover u need to have atleast a suitable mid- woofer & a tweeter.
    If you want to use those then the TDA2030 will be just fine and for that you do not need active crossovers. They are like altec lansing speakers I have seen and are full range, produces a somewhat descent sound if driven within limits, but high range response ain't satisfactory, I donno abt those what you have.
    Seeing the size of the speakers, if they are ur RL channel ones then u can suffice with 2030 or 7240 per side.
    I have to see the woofer to say anything
     
  8. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    U said u have 5.1.
    Then show me all the speakers.
     
  9. Audioguru

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    Of course an active crossover circuit is needed. It keeps the bass out of the tiny speakers that cannot produce bass and keeps the high frequencies out of the woofer that has trouble prouducing high frequencies.
     
  10. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    with those tiny bugger passive will do fine. active crossovers are for drivers that produce better sound. don't you think.
    I don't see why OP have to go via the trouble of active crossover when he can't actually use it's purpose
     
  11. juggler73

    Thread Starter Member

    Apr 10, 2010
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    it was acoustic solutions DS533 5.1 go look it up.
     
  12. juggler73

    Thread Starter Member

    Apr 10, 2010
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    heres the woofer

    if the tda2003 drove the small speakers then how can they be 4.3w when the tda2003 is a 10w amplifier

    thanks
     
  13. retched

    AAC Fanatic!

    Dec 5, 2009
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    Did they sound like crap when you cranked them?

    If not, you should go with the same amp that was in the production design. Reuse it.
     
  14. juggler73

    Thread Starter Member

    Apr 10, 2010
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    yeah it was pretty good, ps2 connected with optical out was really good.

    i could use one tda2003 for one speaker channel but i want to connect them in parallel so i thought why not bridge the tda2003 to boost the two speakers.
    i just wanted to get help in connecting it all up amp to crossover and the power
    thanks
     
  15. retched

    AAC Fanatic!

    Dec 5, 2009
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    Do you have the data sheets for the tda2003? That will be the first step.

    There should be schematics for setting the amp up a few different ways in the data sheet.

    As for the cross over, I would use a lowpass filter on the woofer and a bandpass to the mids.

    Are you looking for a eq you can set or just a few filter caps and call it a day?

    With the filter caps, you can connect them as across the terminals at the speaker. That is recommended.
     
  16. juggler73

    Thread Starter Member

    Apr 10, 2010
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    yeah i have all the schematics
    its only going to be a pc speaker set dont need a EQ

    i found a schematic of a tda2003 amplifier
     
  17. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    So how many amps do you have already working.
     
  18. juggler73

    Thread Starter Member

    Apr 10, 2010
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    i have nothing working yet i cant even get a usable schematic
    i feel like im going in circles
    i want to use the tda2030 for the woofer
    and 2 tda7240 for the speakers 2 in parallel
    a crossover which ever one i need
    and i need to know how to connect all up.
    would i need to have a regulated power supply
    thanks
     
  19. juggler73

    Thread Starter Member

    Apr 10, 2010
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    tda2030a circuit
     
  20. Audioguru

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    Dec 20, 2007
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    The speakers have separate amplifiers so of course an active crossover circuit should be used. He won't need to search for or make inductors for a passive crossover.

    Here is a 12dB/octave Linkwitz-Riley active crossover circuit. The woofer lowpass filter is inverted since even-order crossovers cause a notch at the crossover frequency and the inversion fixes it. The Linkwitz-Riley alignment creates a perfectly flat response (a Butterworth response causes a +3db peak at the crossover frequency).

    It came from this site: http://www.sound.westhost.com/index2.html
     
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