I have bought new logitech z-560 speakers a month ago.I have been
using them for only 7 days and guess what they fried.Bass just stopped
working.I replaced them ( guy at the store said everything inside was
FRIED ! )
I have been reading on the net on the forums,and it seems what
happened to me is not isolated incident,but is happening very often.I
read that if you want to be safe,you should not increase main windows
volume in control panel more then 50 % . However,it's just not enough
for me,I have not paid 200 bucks for speakers who are supposed to be
loud and rock my room,but I just can't turn them up enough to do that
or they will fry.
So my question is if I keep them on 70 % ( in control panel,creative
audio HQ,then master volume ) will they die or not ? What are maximum
settings I can keep them ? Or are they just junk I should throw away ?

Hello Rpglord,

I doubt this answer is worth $50, so I'll just post it as a comment.
If you like it, adjust the price and I'll repost as an answer.

My guess is you are overloading the speakers. A good stereo system can
blow out speakers in a moment if you don't have protection. Since the
small speakers are rated at about 50 Watts RMS, I would go to your
local Radio Shack (or other electronic supply store) and buy...
 - five in line fuse holders
 - four 6 amp fuses (assuming the speakers are 8 ohms - I can't tell
from the "technical documentation" provided - sigh), and a 20 amp
fuse. You may be able to go a little higher on the rating if the fuses
are "fast".
 - Buy spare fuses if you are going to do some significant testing.
Each fuse holder costs about $3 each and the fuses range from $1.50 to
$2.50 each.

Get out a soldering iron and solder the fuse holders in line of the
hot side (not ground) of the wire going to each speaker and plug the
modified wires into your speakers. If you are really overloading the
speakers, the fuses will blow instead of the speakers.

The fuses cost a lot less than the speakers and are cheap insurance. I
don't know why vendors don't sell speakers w/ fuses (or circuit
breakers) to protect the equipment - too cheap I guess.

  --Maniac

Thanks for your response.Now,either you didn't understand me
completely,or I didn't understand you :)
First,I am not connecting these speakers to any stereo system...I am
only connecting them to my pc,because they are meant only for pc,they
are pc speakers !
Second,I am sorry I wasn't precise enough in my first post.It's not
actually
the speakers itself which were fried,but the amp inside the
subwoofer.Speakers
are fine,they were not excanged,but the amplifier inside the subwoofer
was fried.
And third,they already have fusses inside the subwofer,but it didn't
do any good it seems :(
I am willing to pay 50 $ if anyone can get to the bottom of this what
is going on are all z 560 line defective why amlifiers blow,are you
really supposed only to listen them at 50 % level !
Thanks a lot !

Hello Rpglord,

I understood these are speakers w/ integrated amplifiers, I have a
similar set sitting next to me and my computer as well (much lower
power though...). From the description, there are analog speaker
connections from the amplifier (in the sub woofer) to the small
speakers - those are the lines I was mainly concerned about.

But that is not your problem. It is odd that the amplifier is getting
destroyed. I'll take a further look for information on amplifiers, but
one of the other researchers may be able to get you a better answer.

  --Maniac

Hello Rpglord,

A quick follow up with two things to look for:

[1] Open up the amplifier (in the subwoofer?) - and turn up the volume
a few minutes, see how hot the power transistors get. They should be
mounted with large, robust looking heat sinks. If the transistor is
getting hot and the heat sink is not - its time to fix those heat
sinks. If both are hot (could be hot enough to boil water!) - the heat
sinks are too small or you don't have enough ventilation. I would use
a thermometer (I have a dial one w/ a 5" long probe) to measure the
temperature if I was doing this.

[2] Check the impedance of the speakers. Take an ohm meter to the
speakers and subwoofers. It could be that one speaker (or cable) is
damaged - acting like a short. If so, the result would soon be the
destruction of the amplifier for that channel.

These are the two main causes I found for amplifier failure. There are
other causes (e.g, bad design, improper wiring, nuclear blast :-) but
those are less likely.

  --Maniac

Maybe there are fluctuations in your electrical current that affect
your speakers. Do you have a power strip with fuse or circuit breaker
that you plug your speakers to? If not, I suggest you get one.

Logitech Z-560 speakers are good and are highly rated speakers these
days. It's a shame you had to suffer problems with yours.

Some people recommend 'breaking in' speakers that are prone to blow
outs.  Perhaps you could try this.  Turn some music on for about 48
hours at a moderate volume and see if that helps.

I learned from some hardware reviews that the Z-560s were among the
first high-end speakers produced by Logitech after they had absorbed
Labtec. I suppose they had the usual "bugs" associated with initial
development. I believe the problems are not sorted out with the new
stock of Z-560s. It seems that Logitech's earlier stocks of Z-560s are
the ones prone to blowouts.

"I believe the problems *are not* sorted out with the new
stock of Z-560s."

Apologies, that should have been "are now".