woofers:?: educe the humm when woofer is idle

[murali_dece]

la4440 mute

how to reduce the humm when woofer is idle (no audio signal)

 

[taring77]

Re: woofers:?:

Hi
i guess the best way is to switch the woofer off when not in use,
unless ur able to modify the circuit in the woofer.
perhaps u could be more specific as in whether u can modify the cct in the woofer??

regards
taring77

 

[bimbla]

Re: woofers:?:

The ground lines (return paths) of the power and control sections of your PCB are not proper.
This gives low hum at all times.
I was tired of this problem, till the forum members pointed it out. Search the forum for this topic. Correct this and you will get 'silence.'

bimbla.

 

[bimbla]

Re: woofers:?:





Above is the link which details the entire process. Hope it is useful. Do put in your feedback.

bimbla.

 

[murali_dece]

Re: woofers:?:

thanks to friends reply,i used tl084 (quad opamp) for tunable filter design
and la4440 as power amplifier, i want to use mute pin , i have few querrys, when we are using mute pin, at high volumes, sudden switching of mute pin can cause any harm to the woofer,and at switching off of power amp ,the back emf generated in woofer will cause any harm to the power ic, send reply if any protection is required.i want to replace tuning pots with digital controls help me,

murali_dece

 

[bimbla]

Re: woofers:?:

What you need is a slow turn-on and fast turn-off ckt driving a relay.

Same pre-amp secondary winding, seperate rectifier, small filter cap(100UF) an R-C delay ckt which drives a relay will do your job.

I dont trust the in-built pop supressors or the mute pins.

bimbla.

 

[murali_dece]

woofers:?:

i want to modify my woofer cabin ,now it is closed one no vent,give an idea to place the vent ,how to calculate the vent pipe length to obtain required resonance

 

[palesha]

Re: woofers:?:

Pl. visit the online to design
**broken link removed**