woofer cone moves... very wierd.

Thread View: uk.rec.audio

4 messages

[T] Back to Threads [V] Tree View [G] Group Articles

4 total messages Started by Ben Thomas Wed, 23 Dec 1998 00:00

#316

Author: Ben Thomas
Date: Wed, 23 Dec 1998 00:00

15 lines
1322 bytes

Hi all,

If I select the aux input on my old Sansui amp, and turn the
volume up, I can see the woofer cone of my Warfedale
bookshelf speaker on the left channel move outwards, opposite when 
turning down the volume.  if I switch to any other input source, the 
phenomena (sp?) does not occur.

What could cause this?

Thanks in advance!
-- 
Ben Thomas
Quality Assurance - Unico Computer Systems - Melbourne, Australia
Question:  What are eyebrows for anyway?

Re: woofer cone moves... very wierd.

#317

Author: Cameron
Date: Wed, 23 Dec 1998 00:00

9 lines
874 bytes

There is some DC offset that is being introduced to the left
channel when the Aux is selected. Is this happening when the
Aux input is disconnected?

Most likely, whatever you have connected to the Aux has DC
offset in the left channel. Try changing the channels of
that unit around.

Cheers

Re: woofer cone moves... very wierd.

#318

Author: Ben Thomas
Date: Wed, 23 Dec 1998 00:00

23 lines
1717 bytes

Cameron wrote:
> 
> There is some DC offset that is being introduced to the left
> channel when the Aux is selected. Is this happening when the
> Aux input is disconnected?
Only when AUX is selected as the input source.  Not if I use
the tuner or tape connections, which are wierd but I won't
go into that.

> 
> Most likely, whatever you have connected to the Aux has DC
> offset in the left channel. Try changing the channels of
> that unit around.

I had a Pioneer 26 disc player connected via RCA cables, it also
used to do it with my old Sony Discman which had a low input 
via RCA connector.  I think it does it if I connect the Video
via RCAs too.

-- 
Ben Thomas
Quality Assurance - Unico Computer Systems - Melbourne, Australia
Question:  What are eyebrows for anyway?

Re: woofer cone moves... very wierd.

#319

Author: John Woodgate
Date: Wed, 23 Dec 1998 00:00

18 lines
1658 bytes

In a most apposite and timely  article <36805B90.BF89640A@unico.com.au>,
Ben Thomas <ben@unico.com.au> contributes to the sum of human endeavour
>If I select the aux input on my old Sansui amp, and turn the
>volume up, I can see the woofer cone of my Warfedale
>bookshelf speaker on the left channel move outwards, opposite when 
>turning down the volume.  if I switch to any other input source, the 
>phenomena (sp?) does not occur.
>
>What could cause this?

DC offset propagating through the amplifier from the inpout stage. There
may be a failing capacitor somewhere in the chain. If the movement is
more than very little, you had better get it fixed as it could get
catastrophically worse and damage your loudspeaker.
-- 
Regards, John Woodgate, Phone +44 (0)1268 747839 Fax +44 (0)1268 777124. 
OOO - Own Opinions Only. You can fool all of the people some of the time, but 
you can't please some of the people any of the time.

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads