Announcement

Collapse
No announcement yet.

$10 computer speakers

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
    #1

    $10 computer speakers

    Here is more cheap crap that I am trying to fix. These are a set of Cyber Acoustics CA-2012 computer speakers. The CA-2014 speakers are identical to these, and the CA-2011 and CA-2016 are USB powered versions of the same speakers. Most of the sound from these speakers comes from the plastic case resonating.
    These speakers have an insanely bright blue power LED, produce a loud humming noise, and nearby devices cause interference.
    Inside, there is a small circuit board that contains a TDA2822N IC. I can't find a datasheet for that part, but the TDA2822M has the same pinout.

    I first started to investigate the humming problem. The AC adapter is a simple unregulated linear power supply. I checked the voltage on the "7.5V" AC adapter and... look at picture 3. With the amplifier powered on, the voltage across the filter cap is 14.85V, which is extremely close to the TDA2822M's absolute maximum voltage of 15V.

    After replacing the AC adapter with a 5.2V linear regulated adapter, there is no humming. There is still a hissing noise in the background, but it appears even if I power the amplifier with batteries. The interference problem still exists as well.

    These speakers are still being sold and cost $10 at Newegg. However, the suggested retail price is $25. Considering the poor design and sound quality, do you think these are $25 speakers?
    Attached Files
    Tags: None
    #2
    Re: $10 computer speakers

    The humming noise is due to a very small filter cap used after that transformer. If the cap were larger peak voltage would also be lower. Try playing some music and you'll see that supply voltage quickly dips with increasing volume, therefore the IC is "protected". And it sounds like a fart box. Bump the voltage up to 12v regulated and it'll sound half decent.

    The hissing noise is inherent to the 2822, it has too high gain. Same goes for the interference issue. You haven't tried a bridged 2822 - wait till you see the background hiss on that.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

      #3
      Re: $10 computer speakers

      The AC adapter has a 470uF filter cap and the amp has a 220uF filter cap. I also added a 2200uF filter cap and the speakers still hummed. Yes, the transformer is not able to supply enough current to keep the voltage relatively constant. I used the 9V unregulated adapter from my other computer speakers and there was almost no humming and the sound was slightly better. There isn't much you can do to improve the sound of a small driver in a thin plastic enclosure.

      I'm surprised that the hissing is a fault with the TDA2822M, considering that it is designed to be used as either a speaker or headphone amp. I am currently using a 5.5V power supply so I can use the headphone jack. At 12V, the chip produces more power than most headphones can handle.

      These speakers are not used on the same computer as my other Cyber Acoustics speakers. That computer has very poor sound from the headphone jack, but it used to sound good. The computer that I am using these speakers on did not have a working headphone jack. I got the headphone jack working only to discover that it doesn't sound very good either. On this computer, the headphone amp appears to be based on an op-amp, and its sound quality is typical of op-amp based headphone amps.

      Comment

        #4
        Re: $10 computer speakers

        Originally posted by lti View Post
        I'm surprised that the hissing is a fault with the TDA2822M, considering that it is designed to be used as either a speaker or headphone amp.
        Give it a break, it was designed 16 years ago. And it was meant for cheap boomboxes to begin with.
        Originally posted by PeteS in CA
        Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
        A working TV? How boring!

        Comment

          #5
          Re: $10 computer speakers

          I'm assuming that the reason it needs such good power filtering is because it was designed to run on batteries. Almost all cheap computer speakers use the same chip, so the humming problem could affect many models of speakers. Also, these Cyber Acoustics speakers sell for $25 retail and are advertised as being high quality and having good sound quality for their size.

          Comment

            #6
            Re: $10 computer speakers

            Originally posted by lti View Post
            Almost all cheap computer speakers use the same chip, so the humming problem could affect many models of speakers.
            Many models designed by incompetents, yes. You cannot take 2 cheap TV speakers, mold some plastic around them, power them with a 16 year old chip and a quarter of the power supply required (seriously now, how much can a 5W supply cost????) and call it a high quality speaker system.

            Originally posted by lti View Post
            sell for $25 retail and are advertised as being high quality and having good sound quality for their size.
            Aw cmon, do you REALLY believe in marketing blurb? Besides, if you're keen on 2.0 and small footprint, $27.99 will get you those from Logitech. I've used some for a while and they are pretty darn good. You can even get a Logitech 2.1 for $26.99. Guaranteed NOT to be powered by a TDA2822. Logi isn't stellar either, but at least you get a product engineered for the price point, not one that costs $2 to make and sells for $25.
            Last edited by Th3_uN1Qu3; 05-19-2011, 04:12 PM.
            Originally posted by PeteS in CA
            Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
            A working TV? How boring!

            Comment

              #7
              Re: $10 computer speakers

              Originally posted by Th3_uN1Qu3 View Post
              costs $2 to make and sells for $25.
              That's how Cyber Acoustics runs.
              http://www.cyberacoustics.com/
              Look at their products. There are identical speaker systems sold under two different model numbers, everything is overpriced, and they even have video reviews by customers that say the prices are reasonable and the speakers are the best you can buy for the price.
              Where's the "butt-kissing" smiley?

              Comment

                #8
                Re: $10 computer speakers

                you get what you pay for
                Cap Datasheet Depot: http://www.paullinebarger.net/DS/
                ^If you have datasheets not listed PM me

                Comment

                  #9
                  Re: $10 computer speakers

                  When you buy Cyber Acoustics products, you get less than you paid for... much less.

                  Comment

                    #10
                    Re: $10 computer speakers

                    Originally posted by lti View Post
                    When you buy Cyber Acoustics products, you get less than you paid for... much less.
                    Buy a Logitech. You still get less than you paid for... but at least they are worth improving. The 2.0 set i linked to also has a slightly weak power supply - but beefing it up will result in some really solid sound for the size.
                    Originally posted by PeteS in CA
                    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
                    A working TV? How boring!

                    Comment

                      #11
                      Re: $10 computer speakers

                      Altec Lansing are the best Computer speakers I know.

                      Comment

                        #12
                        Re: $10 computer speakers

                        They have gone downhill too. And the cheap models have never been good.
                        Originally posted by PeteS in CA
                        Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
                        A working TV? How boring!

                        Comment

                          #13
                          Re: $10 computer speakers

                          I only needed basic sound. If I need good sound, I just connect my old Fisher stereo to the computer.

                          Comment

                            #14
                            Re: $10 computer speakers

                            I got a CA 2.1 system for this old guy and it works great, sounds good too. I'm sure if I tried to game with it, I could tell the quality

                            but then again, not much is up to par with my Logitech Z-5500 (using dolby live on toslink)
                            Cap Datasheet Depot: http://www.paullinebarger.net/DS/
                            ^If you have datasheets not listed PM me

                            Comment

                              #15
                              Re: $10 computer speakers

                              I've got several sets of cheap speakers like this, some worse quality than others, the best ones I have were also the cheapest (although second hand)

                              Want good cheap speakers? Get them second hand, or free - people give them away or throw them away.
                              "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                              -David VanHorn

                              Comment

                                #16
                                Re: $10 computer speakers

                                I have a Cyber Acoustics 2.0 speaker setup just like that one. I took it apart also...Same exact PCB, except I bought mine 4 years ago.

                                That sure says something. =P

                                Comment

                                  #17
                                  Re: $10 computer speakers

                                  These speakers are about five years old, but the same model is still sold today. I would assume that a new set of these same speakers would be almost identical internally and sound just as bad.

                                  I used to have a good set of Cyber Acoustics speakers, but one of the speakers fried and I was never able to find a replacement. My parents' computer has a set of Harman Kardon 2.0 speakers, but they blew every electrolytic cap in the amplifier. They are good speakers after recapping, but you must use high temperature caps with high ripple current specs. The bass is impressive for 3" drivers.

                                  Comment

                                    #18
                                    Re: $10 computer speakers

                                    Originally posted by TheLaw View Post
                                    I have a Cyber Acoustics 2.0 speaker setup just like that one. I took it apart also...Same exact PCB, except I bought mine 4 years ago.

                                    That sure says something. =P
                                    It says they found a design that 'worked' and there was no sense changing it
                                    "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                    -David VanHorn

                                    Comment

                                      #19
                                      Re: $10 computer speakers

                                      Like seriously. There might have been $3 in parts in that entire speaker, including the power brick. shaking my head. I think I bought them for $15-20

                                      Comment

                                        #20
                                        Re: $10 computer speakers

                                        At work we sell these and people are generally happy with them:
                                        http://www.newegg.com/Product/Produc...82E16836121013

                                        Comment

                                        Previous 1 2 template Next
                                        Working...
                                        X