Toshiba A300 keeps blowing its speakers. What should I do?

[rfsapiens]

Hello people,

I have a Toshiba A300 that had suddenly had problems with the left side of the speakers it started to fade away and distort until it became blown... This happens when I'm playing a music at 100% volume (with default settings without any boost setting turned on) I replaced it with another pair of speakers for the A300 and this time it happened the same with the right speaker.... I tried the hardon kardon speakers from another A300 and not the regular ones and also they got blown... Then I've cut the wires and put the right speaker of the 1st pair with the left speaker of the 2nd one and it worked perfectly until a few days ago that started to distort at any volume so begining to sound desperate I glued the speaker membranes with shoe's glue and it worked they are fine now but the sound is a bit low... Also I measured the impedance from the wires coming from the plug of the motherboard with a multimeter and it read 2.9 ohms. So I tried 3 pairs of speakers and all of them just got the membrane torn and got blown just some of them just took a long time while others just did in about 15 minutes. Volume playback at 100% which it's suposed to handle that just like in any other laptop.
What should I do to restore the sound to what's suposed to be? Should I solder a resistor between a new pair of speakers?

Thank you in advance for your kind help and support.

With the best regards,

Rfsapiens.

 

[JeffMD]

Sounds like your amp is defective. How about switching to a Bluetooth speaker?

 

[rfsapiens]

Dear jeff,

Thank you for your kind reply.
Unfortunely my laptop doesn't have bluetooh or space for the bluetooth module. What else can I do? these glued speakers became a bit sound low due to the glue. the others just got blown. Is there anything I can do to weak the power going to the speakers so that it won't happen again? What else can I do?

With the best regards,

Rfsapiens.

 

[C1]

What your describing sounds classically like what happens to a low end audio amplifier when it is over driven. Mainly it clips, then puts out DC current which then fries the speaker coil. (Such phenomena typically is what destroys tweeters in low end stereo systems when cranking the system up toward max volume..) Try inserting a capacitor in line with one of the speaker wires for blocking of DC current (one needed for each speaker). Start with 0.1uf value. Just guessing a 5v would do.

 

[William Gaatjes]

What your describing sounds classically like what happens to a low end audio amplifier when it is over driven. Mainly it clips, then puts out DC current which then fries the speaker coil. (Such phenomena typically is what destroys tweeters in low end stereo systems when cranking the system up toward max volume..) Try inserting a capacitor in line with one of the speaker wires for blocking of DC current (one needed for each speaker). Start with 0.1uf value. Just guessing a 5v would do.

Although i agree with you.
If turning too loud will make the amplifier clip, he should not turn his speakers up so loud.
Inserting a capacitor with the speakers, is sort of adding a high pass filter because of the low impedance of the speaker. Attenuating the bass (If even present with tiny speakers). I do not know how much space the OP has, but better is to go for a 10uf/16V capacitor for starters.

To the OP :

Most integrated amplifiers function with a bridge tied load (BTL) configuration (Sort of differential output) to increase output power with respect to a single ended amplifier. A H- bridge with the speaker in the center. OP, you need to disconnect the speaker and measure the voltage on both pins of the speaker wires. If i am not mistaken, these should be half of the supply voltage and this voltage should be present on both pins while not playing music. If that is not the case, your amplifier is damaged.

 

[AnitaPeterson]

How about bypassing the internal crappy speakers altogether and use external speakers or a soundbar like the Logitech X300, which can be connected by 3.5mm jack aux input (not just BT, which you don't have)?