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Altec Lansing Rear speakers and subwoofer problem.

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khanvai

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I have a pair of Altec Lansing ACS56 front speakers and another pair of Altec Lansing ACS54 rear speakers and an ACS56 sub woofer. When I connect any of the rear speaker to the front left port on the sub the sound output is much higher than the original port (rear left or rear right port). I know that the 54s has less output capacity then 56. There are TDA7265 amplifier which controls the output of the speaker(one for rear and another for front). So if changing the port can give higher output I believe it is the woofer which needs to be worked on. Besides, plugging in the left front to any of the rear speaker ports reduces the front left's output.

My question is how I can increase the output of the amplifier?
I am totally a novice to electronics. But I think if anybody can help I can work it out.:confused: Just give me detail instructions. Thanks
 

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You are overloading the amplifier which might destroy it.
Each amplifier output is designed to drive only ONE speaker.
You cannot have more output power than it was designed for.
 
You are overloading the amplifier which might destroy it.
Each amplifier output is designed to drive only ONE speaker.
You cannot have more output power than it was designed for.

Hi audioguru,

I am including a PDF file on TDA7265 specification. On the very first page you will see a diagram
which I believe actually shows that the amp is usable for two speakers. And this link

https://translate.google.com/transl...rhoney.idv.tw/Speakers/ACS56&biw=1920&bih=958

In which beneath the 10th picture it is written- "ACS56 using two ST's TDA7265. TDA7265 is a dual 25W power crystals, there is the theoretical value equal to the maximum total output power of 100W satellite speakers" So do you think It is possible to do anything.

According to altec all of the speakers are full range, their amplifier should provide equal output.

I f it is impossible to do anything with the sub can I do any shorts of adjustments like changing the mikes of the rear speakers? Please suggest. -Thanks
 

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  • tda7265.pdf
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I am not familiar with the ACS56 but it is possible that the TDA7265 is being used in a bridge configuration (see Fig 17 of the datasheet), in which case it can drive only one speaker.
 
I remember when Altec Lansing was a high quality American company. Now they are Taiwanese making little pc speakers?

Those dinky little 3" satellite speakers are probably made for 5W or 10W each, not 35W.
The little 6.5" woofer is not a sub-woofer and it might be built for 20W or 30W, not 35W.

The amplifiers in the TDA7265 "crystals" (bad translation) clip at 18W into 4 ohms or 8 ohms when the supply voltage is very high but here the supply voltage is probably fairly low. Maybe the TDA7294 is bridged with a low supply voltage for 25W or 35W to the woofer.

Overloading the amplifiers probably causes the supply voltage to drop which reduces the power in the speakers and might destroy the power supply.
 
Hello guys,

So I am back again. I have taken some pictures of my sub's circuit board. Surprising enough there are only three amps. One TDA7284 (which is for the sub I think) and another two TDA7265s for the 4 speakers(each for each speaker pair).

But according to all of you it should be 1 amp for 1 speaker right? But I don't know what is really happening here. There suppose to be 6 amps ( if I am not wrong ), now whats going on?
The sfx volume was scanned with KIS 2013 so don't worry about it.

Thanks.
 

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  • ALTEC Subwoofer Pics.exe
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Why don't you look at the datasheet of the TDA7265? It is a STEREO amp IC (stereo means TWO channels).
So two ICs are used for the four front and back satellite speakers and one IC has its two channels bridged for lots of power to the sub-woofer.

I will never open a huge EXE file. Why don't you post the images like everybody else?
 

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You are overloading the amplifier which might destroy it.
Each amplifier output is designed to drive only ONE speaker.
You cannot have more output power than it was designed for.

Why don't you look at the datasheet of the TDA7265? It is a STEREO amp IC (stereo means TWO channels).
So two ICs are used for the four front and back satellite speakers and one IC has its two channels bridged for lots of power to the sub-woofer.

I will never open a huge EXE file. Why don't you post the images like everybody else?

audioguru,

I have mentioned that I am a novice in electronics. And I mean it. I cannot even read the "E" of "Electronics". So all of this questions that I ask might bother experts like you. In your first answer you said "Each amplifier output is designed to drive only ONE speaker."

Am I missing anything?

In the last answer you wrote "So two ICs are used for the four front and back satellite speakers". So each TDA7265 is for two speakers (front or rear or whatever).
 

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  • 4.TDA7265 Both.jpg
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  • 1.Back.jpg
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In your first answer you said "Each amplifier output is designed to drive only ONE speaker."

Am I missing anything?

Look back at the attachment AG has in post #7 and look at the section on the left, for stereo output.
How many inputs/outputs are there?



In the last answer you wrote "So two ICs are used for the four front and back satellite speakers". So each TDA7265 is for two speakers (front or rear or whatever).

One amp for the front pair, another amp for the rear pair, then another bridged for the woofer.

What you seem to have missed, is this part:
"Each amplifier output is designed to drive only ONE speaker."
 
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