Guys, help me understand:

If my speakers handle 100W RMS and peak at 250W
and my amp pushes 120W RMS and peaks at 300W

what happens?

Will the speakers blow?

Does adjusting the gain on the amp effectively cut the wattage?

If so, how do I truly know that I've cut enough gain to not blow the
speakers?

Guys, help me understand:

If my speakers handle 100W RMS and peak at 250W
and my amp pushes 120W RMS and peaks at 300W

what happens?

Will the speakers blow?

Not likely. But it's impossible to predict based on the information you've
provided. Anyone who tries to is wrong.

Does adjusting the gain on the amp effectively cut the wattage?

Not if you still turn the volume knob up enough to achieve the same output
level.

If so, how do I truly know that I've cut enough gain to not blow the
speakers?

The gain cannot be used to prevent overpowering your speakers. And it's not
wise to attempt to either.

It's very difficult to blow speakers (those that aren't defective from the
getgo, that is). If you worry all the time about blowing your speakers, you
won't enjoy the music. Forget about it.

Hi,

Unless you use your system at full volume most of the time, I wouldn't
worry too much about blowing the speakers. This is assuming that the
values you gave for the amplifier are "per channel", so a total of 240
Wrms and 600 Wmax for a 2-channel amp. Can you provide the brandname
and model for both the speaker and the amp ?

The gain control should be used on the amplifier to match the voltage
output of your head unit. If you use your amplifier to control a
subwoofer, you can use the gain as a volume control, but you should
first set it properly and use the control to _reduce_ the "volume".
Do not try to increase the gain, since this might create clipping,
which result in very bad sound quality, ans possibly some damage, but
not everyone agree on the actual possible damage. It is not a volume
control, and should not be used as such.

Andre.

Matt Bhame wrote in message ...
Guys, help me understand:

If my speakers handle 100W RMS and peak at 250W
and my amp pushes 120W RMS and peaks at 300W

what happens?

Will the speakers blow?

Does adjusting the gain on the amp effectively cut the wattage?

If so, how do I truly know that I've cut enough gain to not blow the
speakers?

Hi,

Unless you use your system at full volume most of the time, I wouldn't
worry too much about blowing the speakers. This is assuming that the
values you gave for the amplifier are "per channel", so a total of 240
Wrms and 600 Wmax for a 2-channel amp. Can you provide the brandname
and model for both the speaker and the amp ?

The gain control should be used on the amplifier to match the voltage
output of your head unit. If you use your amplifier to control a
subwoofer, you can use the gain as a volume control, but you should
first set it properly and use the control to _reduce_ the "volume".
Do not try to increase the gain, since this might create clipping,
which result in very bad sound quality, ans possibly some damage, but
not everyone agree on the actual possible damage. It is not a volume
control, and should not be used as such.

Andre.

No, full-volume will *not* be used most of the time. In fact, this
vehicle won't be used most of the time; not a daily-driver.

The amp is a Rockford-Fosgate 401S, which they say is 100Wx2 RMS.

The speakers are an old MB Quart 3-way component line that I've been
told peaks at 130W. I don't remember the model offhand: i'll have to
ask my buddy whom I'm asking in behalf for. BTW, if you know where to
get some old MB Quart MCX 328 MusicComp crossovers, I'd appreciate it.

The second amp is identical and will be bridged (400Wx1 RMS) to drive an
old 12" PPI Precision Power Pro sub, tentatively in a 1 cu. ft. sealed
enclosure.

We have no info on the sub itself as of yet. We've been told PPI
changed ownership a few times and current intellectual owner has little
interest in the old stuff.

Anyways, the amp RMS's @ 100W per channel and the speakers peak at 130W
and we're wondering the ramifications of pushing it past the speakers'
peak limit.

I trust this group's opinion so don't misunderstand why I ask this - I
ask out of sheer ignorance - but why do you guys say to more or less
ignore a manufacturer's peak wattage rating? Why, then, does such a
rating exist?

Can you further-explain what you mean when you said, "The gain control
should be used on the amplifier to match the voltage output of your head
unit." please? I don't quite understand.

My buddy *was* considering of using the wired GAIN remote w/RF amps for
his sub volume - do you mind further explaining what you meant when you
said, "If you use your amplifier to control a subwoofer, you can use the
gain as a volume control, but you should first set it properly and use
the control to _reduce_ the "volume". Do not try to increase the gain,
since this might create clipping, which result in very bad sound
quality, ans possibly some damage, but not everyone agree on the actual
possible damage. It is not a volume control, and should not be used as
such." I don't understand because you say I *can* use it as volume
control but your last sentence says it's *not* a volume control and
don't use it as such. I don't know that I understand the scene enough
to be able to fill in my blanks, sorry.

I appreciate your guys' help - thanks!

matt

No, full-volume will *not* be used most of the time. In fact, this
vehicle won't be used most of the time; not a daily-driver.

It doesn't matter much how often you use it actually.


The amp is a Rockford-Fosgate 401S, which they say is 100Wx2 RMS.

The speakers are an old MB Quart 3-way component line that I've been
told peaks at 130W. I don't remember the model offhand: i'll have to
ask my buddy whom I'm asking in behalf for. BTW, if you know where to
get some old MB Quart MCX 328 MusicComp crossovers, I'd appreciate it.

The second amp is identical and will be bridged (400Wx1 RMS) to drive an
old 12" PPI Precision Power Pro sub, tentatively in a 1 cu. ft. sealed
enclosure.

We have no info on the sub itself as of yet. We've been told PPI
changed ownership a few times and current intellectual owner has little
interest in the old stuff.

Anyways, the amp RMS's @ 100W per channel and the speakers peak at 130W
and we're wondering the ramifications of pushing it past the speakers'
peak limit.

You'll be fine.


I trust this group's opinion so don't misunderstand why I ask this - I
ask out of sheer ignorance - but why do you guys say to more or less
ignore a manufacturer's peak wattage rating? Why, then, does such a
rating exist?

Those ratings exist so they can stamp a higher power number on the box.
There's really no such thing as "peak power", because the calculation is
based on infinitesimal time periods. Power is a time-rate. So when
arriving at a "peak power" calculation, you're looking at the power over a
time period of 0. Well, speakers don't care about what happens during a
time period of zero. They can't heat up enough in zero seconds to be
damaged.

Most manufacturers simply double the average power to arrive at a peak power
rating. Oftentimes, a peak power measurement is used instead. This is
something entirely different, but just as irrelevant. It's based on forcing
the amplifier to do something that it will not experience under normal
conditions. For instance, short-duration bursts of a given frequency in a
given envelope and a given supply voltage.

Can you further-explain what you mean when you said, "The gain control
should be used on the amplifier to match the voltage output of your head
unit." please? I don't quite understand.

He means that the gain control is typically used to set the range of the
volume control. For instance, if you turn the gain way up, the head unit
volume control may only reach 1/5th of the way before the amp starts to
clip. This gives you very little volume adjustment resolution. That is,
the difference in volume between two adjacent volume levels will be too
high. On the other hand, if the gain is turned all the way down, then even
at the maximum volume setting on the head unit, the amplifier will only be
delivering a small amount of power to the speaker - hence it's quieter than
you want it.

My buddy *was* considering of using the wired GAIN remote w/RF amps for
his sub volume - do you mind further explaining what you meant when you
said, "If you use your amplifier to control a subwoofer, you can use the
gain as a volume control, but you should first set it properly and use
the control to _reduce_ the "volume". Do not try to increase the gain,
since this might create clipping, which result in very bad sound
quality, ans possibly some damage, but not everyone agree on the actual
possible damage. It is not a volume control, and should not be used as
such." I don't understand because you say I *can* use it as volume
control but your last sentence says it's *not* a volume control and
don't use it as such. I don't know that I understand the scene enough
to be able to fill in my blanks, sorry.

A gain control IS a volume control. But it's not very convenient because
it's hard to crawl into your trunk to adjust it when you're driving. That's
why the head unit volume control is used for that instead. The gains should
be adjusted to maximize the usable "range" on your head unit (as I described
above).