When the unit is changing CD tracks there is a low level, fairly low
frequency 'blubbering' sound from all speakers. This is the only time I hear
it, and it's quiet enough that it's not objectionable. Could it be the
stepping motor is poorly filtered or something like that? Not discernable
during quiet passages in music.
TIA

- - - - - - - - - - - - - - - - - - -
Easy's getting harder everyday

Check to make sure the unit is properly grounded, and if need be, re-ground
it.

Tony


--
2001 Nissan Maxima SE Anniversary Edition
Clarion DRZ9255 Head Unit, Phoenix Gold ZX475ti, ZX450 and Xenon X1200.1
Amplifiers, Dynaudio System 360 Tri-Amped In Front and Focal 130HCs For Rear
Fill, Image Dynamics IDMAX10 D4 v.3 Sub

2001 Chevy S10 ZR2
Pioneer DEH-P9600MP Head Unit, Phoenix Gold Ti500.4 Amp, Focal 165HC
Speakers & Image Dynamics ID8 D4 v.3 Sub

2006 Mustang GT Coupe
Alpine IVA-D310 DVD Head Unit, Alpine MRA-550 Digital 5.1 Amp, Boston
Acoustics Z-Series Speakers, Alpine SBS-05DC Center Channel Speaker,
Amplified MTX Thunderform Sub

"Tony F" wrote in message
...
Check to make sure the unit is properly grounded, and if need be,
re-ground it.

Thanks Tony.

Are you using an amplifier?

I actually had some problems with my current system that sound very similar
to yours. Every time I changed tracks, I heard this loud thump from my
subwoofers. It turned out it was actually a phasing issue (I had combined
the left and right channel of the subwoofer outputs) and this was causing
the problems. I was able to fix it by wiring my sub amp differently (and
adjusting a switch on my SS Ref. 700). If you are using an amplifier, it
might (and I do mean MIGHT) have something to do with that.

If you are not using an amp, then Tony's suggestion of checking grounds
would be the first place to start.

Also, does this happen in all speakers?

MOSFET



"PanHandler" wrote in message
. ..
When the unit is changing CD tracks there is a low level, fairly low
frequency 'blubbering' sound from all speakers. This is the only time I
hear
it, and it's quiet enough that it's not objectionable. Could it be the
stepping motor is poorly filtered or something like that? Not discernable
during quiet passages in music.
TIA

- - - - - - - - - - - - - - - - - - -
Easy's getting harder everyday

"MOSFET" wrote in message
news
Are you using an amplifier?

I actually had some problems with my current system that sound very
similar to yours. Every time I changed tracks, I heard this loud thump
from my subwoofers. It turned out it was actually a phasing issue (I had
combined the left and right channel of the subwoofer outputs) and this was
causing the problems. I was able to fix it by wiring my sub amp
differently (and adjusting a switch on my SS Ref. 700). If you are using
an amplifier, it might (and I do mean MIGHT) have something to do with
that.

If you are not using an amp, then Tony's suggestion of checking grounds
would be the first place to start.

Also, does this happen in all speakers?

Yeah. I've gotten advice to add ferrite cores to the signal cords, and an
electrolytic to the 35 Amp 12 Volt power supply leads. This is the setup:
http://flickr.com/photos/43996336@N00/?saved=1 It's a 'portable' sound
system. One of the pics will show a close-up of the power supply.

Yeah. I've gotten advice to add ferrite cores to the signal cords, and an
electrolytic to the 35 Amp 12 Volt power supply leads. This is the setup:
http://flickr.com/photos/43996336@N00/?saved=1 It's a 'portable' sound
system. One of the pics will show a close-up of the power supply.


WOW!! That's quite a set-up you've got going. It looks like you have a lot
of fun with it as well!! Very cool!

I'm not sure why adding ferrite cores to the signal cords would do any good.
This is a tactic more frequently employed to deal with some type of induced
noise like alternator whine or some other kind of "hum". That does not
sound like your problem as it happens only when changing tracks, correct?

As far as adding a large electrolytic capacitor to your power supply, those
are typically added to the power supply in cars to help stabilize the
voltage when the demands of the system exceed the available current. This
is very useful because music (in particular, Rock music) produces transient
demands for power. In other words, when the bass drum hits, this demands
more power than other times. Therefore, a capacitor can charge between bass
drum hits, and release current when the drum hits. This is not a bad idea
in your situation (this may add more "Oomph" to your system if your power
supply is limited to 35 amps). But again, this DOES NOT sound like the
source of your problem, though it may be a good idea for other reasons.

If your system is connected to an amplifier, the first thing I would do is
see if it happens when the amplifier is connected or not. Try connecting a
speaker directly to your HU and see if this noise occurs that way. If not,
then it is something to do with the interaction of your HU and amp. If the
noise is still present, then I would continue trying to focus on a grounding
problem.

MOSFET

"MOSFET" wrote in message
m...

WOW!! That's quite a set-up you've got going. It looks like you have a
lot of fun with it as well!! Very cool!

Thanks. It's going out on it's first party at a club tomorrow night.

I'm not sure why adding ferrite cores to the signal cords would do any
good. This is a tactic more frequently employed to deal with some type of
induced noise like alternator whine or some other kind of "hum". That
does not sound like your problem as it happens only when changing tracks,
correct?

Yup, and it's not affected by the volume control either. Not heard with the
radio.

As far as adding a large electrolytic capacitor to your power supply,
those are typically added to the power supply in cars to help stabilize
the voltage when the demands of the system exceed the available current.
This is very useful because music (in particular, Rock music) produces
transient demands for power. In other words, when the bass drum hits,
this demands more power than other times. Therefore, a capacitor can
charge between bass drum hits, and release current when the drum hits.
This is not a bad idea in your situation (this may add more "Oomph" to
your system if your power supply is limited to 35 amps). But again, this
DOES NOT sound like the source of your problem, though it may be a good
idea for other reasons.

If your system is connected to an amplifier, the first thing I would do is
see if it happens when the amplifier is connected or not. Try connecting
a speaker directly to your HU and see if this noise occurs that way. If
not, then it is something to do with the interaction of your HU and amp.
If the noise is still present, then I would continue trying to focus on a
grounding problem.

It is connected to an amp. I'm only using the HU to play mp3's off my
laptop/external HD, and CD's. No speakers connected to the HU, but I'll give
that a shot tomorrow.