I have a 4 channel amp with 2 x 300W rms (bridged) channels. My kenwood
splits is running off two of the 4 channels.

So I have 1x300W rms available. I need a sub that won't be damage no matter
how loud I turn the volume. I don't want to pay a lot of money only to
destroy the sub.

Anyone know of a sub that can handle quite some torture?

I just want to be safe thats all

The problem you're going to run into is that subs are rated
assuming a clean input signal. If you really overdrive your amp, you
will output a clipped signal that will reduce the power-handling
capabilities of the subwoofer significantly. So a "1000-watt
subwoofer" might end up being damaged by your 300-watt amp.
One thing you could do is adjust the amplifer gains so that no
matter how loud you turn up the volume, the amp never clips. The
problem with this method is that when you have the volume on the head
unit turned all the way up to maximum, you're likely to get clipping
from the head unit.
The best overall method would be to turn the gains down on the
amp until you can barely hear any sound, then turn the head unit up
until the sound starts distorting (it won't be loud, since you have
the amp gains down so far, but it will be distorted). Now, turn the
head unit down until the distortion goes away. That is the highest
you should ever raise the volume on your head unit, ever.
Now, with the head unit at its loudest non-distorting setting,
turn the gain on the amplifier up until it begins to distort (This
will be quite loud, so don't do this step at 3 AM in a residential
neighborhood.) Once you hear the distortion, turn the gain back down
until it goes away.
Now you have your head unit and amplifier adjusted to provide
maximum clean output at the same time. This will maximize your
signal-to-noise ratio and keep you from damaging your speaker, as long
as your speaker can handle 300W RMS and you never turn the head unit
past the maximum you determined while you were adjusting the gains.

Scott Gardner


On Mon, 1 Dec 2003 21:46:35 +0200, "Johan Wagener"
wrote:

I have a 4 channel amp with 2 x 300W rms (bridged) channels. My kenwood
splits is running off two of the 4 channels.

So I have 1x300W rms available. I need a sub that won't be damage no matter
how loud I turn the volume. I don't want to pay a lot of money only to
destroy the sub.

Anyone know of a sub that can handle quite some torture?

I just want to be safe thats all

IMHO youre asking the impossible.
Any sub can be damaged with a clipped signal. A 300 watt clipped signal
will toast any voice coil, regardles of wattage capacity.

IMHO the only way to be safe is to use a 300W RMS sub and use caution. Turn
it up till you hear "distress" - either the woofer distorting or the amp
clipping, and back down the vol knob.

If the above scenario does not appeal, and you still must crank into
oblivion, then how about an MTX RFL or something similar that is
rebuildable. Beware though, thats an SPL sub with an Fs of 65Hz. It would
be like going to costco in a 1/4 top fuel dragster to pick up clam chowder
and diapers.

:~)
Garrett

"Johan Wagener" wrote in message
...
I have a 4 channel amp with 2 x 300W rms (bridged) channels. My kenwood
splits is running off two of the 4 channels.

So I have 1x300W rms available. I need a sub that won't be damage no
matter
how loud I turn the volume. I don't want to pay a lot of money only to
destroy the sub.

Anyone know of a sub that can handle quite some torture?

I just want to be safe thats all

"Scott Gardner" wrote in message
...
The problem you're going to run into is that subs are rated
assuming a clean input signal. If you really overdrive your amp, you
will output a clipped signal that will reduce the power-handling
capabilities of the subwoofer significantly. So a "1000-watt
subwoofer" might end up being damaged by your 300-watt amp.


No. It. Won't. You can clip a 300 watt amp all day long into a 1000 watts
sub (assumming it can really handle 1000 watts) and it will be fine.
Clipping doesn't do anything but make more power and sound like ass. If you
don't exceed the sub's thermal limits you'll be fine.


Paul Vina

IMHO youre asking the impossible.
Any sub can be damaged with a clipped signal. A 300 watt clipped signal
will toast any voice coil, regardles of wattage capacity.


Are you serious? Please see my previous post on this thread.



IMHO the only way to be safe is to use a 300W RMS sub and use caution.
Turn
it up till you hear "distress" - either the woofer distorting or the amp
clipping, and back down the vol knob.


That makes sense, but not because clipping hurts anything, because it will
sound like ass.


Paul Vina

On Tue, 02 Dec 2003 01:05:34 GMT, "Paul Vina"
wrote:


"Scott Gardner" wrote in message
...
The problem you're going to run into is that subs are rated
assuming a clean input signal. If you really overdrive your amp, you
will output a clipped signal that will reduce the power-handling
capabilities of the subwoofer significantly. So a "1000-watt
subwoofer" might end up being damaged by your 300-watt amp.


No. It. Won't. You can clip a 300 watt amp all day long into a 1000 watts
sub (assumming it can really handle 1000 watts) and it will be fine.
Clipping doesn't do anything but make more power and sound like ass. If you
don't exceed the sub's thermal limits you'll be fine.


Paul Vina


That's my whole point. How can say what the thermal limit of the sub
is when you're feeding it a badly-clipped waveform? The 1000-watt
rating is predicated on the voice coil receiving adequate cooling from
the motion of the speaker cone. If you're clipping the signal badly,
the cone motion is going to be reduced, reducing the ability to cool
the voice coil. Since we're now subjecting the sub to conditions it
wasn't designed for, who can say *what* the sub's thermal limits are
now?

Remember - speaker power handling ratings assume an unclipped input.

Scott Gardner

Perhaps I was generalizing a bit. Its not that cut & dry, some voice
coils can withstand more heat than others and not all amps clip their
waveforms identically.

I am carefull with my gear and have never toasted a sub coil before. I
did kill a JBL midrange once about 10 years ago... burnt that coil to a
crisp. Fortunately I was already judged, so It didn't hurt my SQ
score. So I dont have 1st hand experience with subs. A friend of mine
cooked his 12L7 coil with an underpowered amp pushed to clipping... he
wasn't too happy.

Garrett

Paul Vina wrote:

IMHO youre asking the impossible.
Any sub can be damaged with a clipped signal. A 300 watt clipped signal
will toast any voice coil, regardles of wattage capacity.




Are you serious? Please see my previous post on this thread.




IMHO the only way to be safe is to use a 300W RMS sub and use caution.


Turn


it up till you hear "distress" - either the woofer distorting or the amp
clipping, and back down the vol knob.




That makes sense, but not because clipping hurts anything, because it will
sound like ass.


Paul Vina

It wasn't the clipping that killed the sub, it was the power. Period. a
bproduct of clipping is more voltage to the speaker, that's what kills it.
Not a square wave or any other such nonsense.


Paul Vina



"sanitarium" wrote in message
...
Perhaps I was generalizing a bit. Its not that cut & dry, some voice
coils can withstand more heat than others and not all amps clip their
waveforms identically.

I am carefull with my gear and have never toasted a sub coil before. I
did kill a JBL midrange once about 10 years ago... burnt that coil to a
crisp. Fortunately I was already judged, so It didn't hurt my SQ
score. So I dont have 1st hand experience with subs. A friend of mine
cooked his 12L7 coil with an underpowered amp pushed to clipping... he
wasn't too happy.

Garrett

Paul Vina wrote:

IMHO youre asking the impossible.
Any sub can be damaged with a clipped signal. A 300 watt clipped signal
will toast any voice coil, regardles of wattage capacity.




Are you serious? Please see my previous post on this thread.




IMHO the only way to be safe is to use a 300W RMS sub and use caution.


Turn


it up till you hear "distress" - either the woofer distorting or the amp
clipping, and back down the vol knob.




That makes sense, but not because clipping hurts anything, because it
will
sound like ass.


Paul Vina

True, it's the power that kills the sub, but subjecting a sub to a
clipped waveform reduces the amount of power required to do damage,
since the reduced cone motion as a result of being fed a square wave
reduces the cooling for the voice coil.

Scott Gardner


On Tue, 02 Dec 2003 04:39:38 GMT, "Paul Vina"
wrote:

It wasn't the clipping that killed the sub, it was the power. Period. a
bproduct of clipping is more voltage to the speaker, that's what kills it.
Not a square wave or any other such nonsense.


Paul Vina



"sanitarium" wrote in message
...
Perhaps I was generalizing a bit. Its not that cut & dry, some voice
coils can withstand more heat than others and not all amps clip their
waveforms identically.

I am carefull with my gear and have never toasted a sub coil before. I
did kill a JBL midrange once about 10 years ago... burnt that coil to a
crisp. Fortunately I was already judged, so It didn't hurt my SQ
score. So I dont have 1st hand experience with subs. A friend of mine
cooked his 12L7 coil with an underpowered amp pushed to clipping... he
wasn't too happy.

Garrett

Paul Vina wrote:

IMHO youre asking the impossible.
Any sub can be damaged with a clipped signal. A 300 watt clipped signal
will toast any voice coil, regardles of wattage capacity.




Are you serious? Please see my previous post on this thread.




IMHO the only way to be safe is to use a 300W RMS sub and use caution.


Turn


it up till you hear "distress" - either the woofer distorting or the amp
clipping, and back down the vol knob.




That makes sense, but not because clipping hurts anything, because it
will
sound like ass.


Paul Vina