Adding a passive subwoofer to stereo amp

[Laputacake]

Hi,

 

I've tried having a look on google to see if anyone has tried this before but havent had any success so... I'm currently using a TPA3116d2 2.1 amp but im missing the sound of my old Class A amp but the only issue is the majority of older amps dont have any subwoofer output like the TPA. Would it be possible to use a low pass filter combined with a Y adapter to take the L and R signal from the amp combine them and then send that LPF signal to the passive subwoofer. Probably not the best explanation so enjoy some paint.

 

 

Thanks for the help

[The Flying Sloth]

Yes it's possible though you wouldn't have direct volume controls on the speaker vs subwoofer ratio, what you're missing isn't your class A amp it's the lack of detail in those $10 class D single board amps.

Personally, I'd split the input signal, send it through the TPA for sub and class A for stereo, best of both worlds.

Sloth

[Laputacake]

On 5/4/2020 at 11:39 PM, The Flying Sloth said:

Yes it's possible though you wouldn't have direct volume controls on the speaker vs subwoofer ratio, what you're missing isn't your class A amp it's the lack of detail in those $10 class D single board amps.

Personally, I'd split the input signal, send it through the TPA for sub and class A for stereo, best of both worlds.

Sloth

How would you be able to split the input signals to send only the low frequencies to the TPA? Or just send all the frequencies to both and have only the sub connected but that would still need the signals to be combined somehow.

 

Cheers

[Blade of Grass]

 

42 minutes ago, Laputacake said:

How would you be able to split the input signals to send only the low frequencies to the TPA? Or just send all the frequencies to both and have only the sub connected but that would still need the signals to be combined somehow.

 

Cheers

You would use a crossover

[The Flying Sloth]

2 hours ago, Laputacake said:

-snip-

Apologies, I assumed you had a crossover since you were trying to bridge the sub on the same amp outs as your stereo speakers,
Either buy a crossover or build one with passive components, it's really not hard.

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