What causes the thud when shutting off?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=13143
Printed Date: July 31, 2025 at 1:21 AM

Topic: What causes the thud when shutting off?

Posted By: turd
Subject: What causes the thud when shutting off?
Date Posted: May 04, 2003 at 7:04 PM

When I turn my head unit off, it causes a thud through the speakers........like a high power amp shutting off......only I am not running a high power amp, just the head unit.

Would it be a bad ground?

Replies:

Posted By: esmith69
Date Posted: May 04, 2003 at 7:28 PM

What kind of vehicle do you have and did the vehicle come with a premium sound system? A lot of times what you are describing is the turn on/off thump made by the factory amplifier of the vehicle.

-------------
Ethan
-----
"Patience, persistence, and perspiration make an unbeatable combination for success"
Donate to the12volt.com

Posted By: turd
Date Posted: May 05, 2003 at 7:02 AM

esmith69 wrote:

What kind of vehicle do you have and did the vehicle come with a premium sound system? A lot of times what you are describing is the turn on/off thump made by the factory amplifier of the vehicle.

Actually it is an older ?Blaupunt? with a 10 disk cd changer into my 1967 Mustang.

Due to the dash console, I had to use my older unit, otherwise I would have bought a new headunit.

Any way, it works, just now makes a thud like it was some kind of monster amp that was hooked-up?????

Posted By: greenbroncoguy
Date Posted: May 07, 2003 at 5:37 AM

i have a pioneer DEH-P6400 that does the exact same thing as well as when i turn the volume down to 00 and then back up it will do it too, it is weird

Posted By: turd
Date Posted: May 07, 2003 at 11:05 AM

Any one have any idea?????

Posted By: thepencil
Date Posted: May 07, 2003 at 12:21 PM

Turning down the volume before shutting down the unit will usually do the trick.

The other thing I can tell you is that sometime the unit may have a built in delay to turn itself on or off. This delay to turn on/off may cause an audible "pop" or "thud" when turning the system on or off.

-------------
Be careful whose advice you buy, but be patient with those who supply it. posted_image

Posted By: greenbroncoguy
Date Posted: May 16, 2003 at 5:30 AM

turning down the volume wouldnt help because when your go from 01 on the volume setting to 00, it makes the same popping noise from the speakers.

Posted By: pinchy
Date Posted: May 16, 2003 at 2:30 PM

I actually get the same problem running a sony cdx-ca900x and an infinity basslink. I have the remote turn on wire connected, rca plugs for my rear sub inputs, and speaker lines for my front sub inputs. With the remote turn on feature enabled, I get the same thud sound when i power the head unit off and on. Infinity says the speaker lines are faking out the unit and to disable the remote turn on feature, so i did. Now I get a thud when I change radio stations and when I go from tuner to cd. Seems like a lose-lose situation.