Author Topic: Noise from laptop HDMI output - SMPS  (Read 1010 times)

Offline alvin1118

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Noise from laptop HDMI output - SMPS
« on: March 14, 2012, 12:12 »
Recently updated my old Dell Studio 1555 AMD Radeon 4500 drivers and happy to find out that this old tech stuff can output 5.1/7.1 and decode DTS and DD!!

i was very excited but something bad crop-up. there's audible noise/hum from my sub-woofer due to the noisy nature of SMPS. whenever i plug in the power adapter to laptop, my sub-woofer will happily sing the noise i guess @ 50hz. the rest of the speakers are fine and quiet.

i believe many bros here have similar issue, what to do to get rid of the noise? of course using battery-only will solve the problem but battery performance not-so-good leh :(

Offline alvin1118

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Re: Noise from laptop HDMI output - SMPS
« Reply #1 on: March 21, 2012, 09:38 »
Need help ! Any kind bros care to advice?

Offline tree

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Re: Noise from laptop HDMI output - SMPS
« Reply #2 on: March 26, 2012, 10:02 »
Hi Alvin,
Can u pls share more abt hum cos i am also using a notebook (with Nvidia graphics) for playback and have not heard of the issue.

Cheers

Offline wwenze

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Re: Noise from laptop HDMI output - SMPS
« Reply #3 on: March 29, 2012, 20:43 »
Probably not SMPS switching noise, but grounding issues.

Not much you can do about it. You can try doing this on one of the plug (have everything else properly connected before powering on). Is your subwoofer a powered one?

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Offline alvin1118

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Re: Noise from laptop HDMI output - SMPS
« Reply #4 on: March 29, 2012, 20:55 »
Powered sub , whenever I plug in my adapter, there's zzz uuuu noise audible from sub , the rest of the spks are perfectly fine.

I've the same experience with usb dac with laptop, same sort of noise.

Offline wizardofoz

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Re: Noise from laptop HDMI output - SMPS
« Reply #5 on: March 29, 2012, 23:33 »
Powered sub , whenever I plug in my adapter, there's zzz uuuu noise audible from sub , the rest of the spks are perfectly fine.

I've the same experience with usb dac with laptop, same sort of noise.

How old is the adaptor...maybe got capacitor issues?
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