I am running one 8-ohm 10" sub off a bridged amp which supplies 300W rms. I
will be adding a second identical 10" sub and will wire it in parallel to
create a 4-ohm load.

At the moment the one sub performs nice and produces good sounding bass but
it is not loud enough. How big will the difference be when I add the second
sub? Will the one currently in the car perform better when the load becomes
4-ohm? resistors in parallel = current dividers but I can't seem to figure
out wheter the sub thats in there at the moment will use more current.

My amp has a 12dB bass boost at 45Hz. Can I use this on these subs? I am
afraid that it will damage the subs.

Output power of amp when bridged = 300W rms. Subs is rated 175W nominal and
350W max.

Thank you

I am running one 8-ohm 10" sub off a bridged amp which supplies 300W rms.
I
will be adding a second identical 10" sub and will wire it in parallel to
create a 4-ohm load.

At the moment the one sub performs nice and produces good sounding bass
but
it is not loud enough. How big will the difference be when I add the
second
sub?

~3dB. Ooooh I get the easy ones!

Will the one currently in the car perform better when the load becomes
4-ohm? resistors in parallel = current dividers but I can't seem to figure
out wheter the sub thats in there at the moment will use more current.

Current doubles with parallel equivalent loads. If the two subs are
equivalent, why would one draw more than the other?

My amp has a 12dB bass boost at 45Hz. Can I use this on these subs? I am
afraid that it will damage the subs.

A bass boost in and of itself can't damage speakers. It can only if the
resultant power output exceeds the power handling capabilities of the
driver.

Current doubles with parallel equivalent loads. If the two subs are
equivalent, why would one draw more than the other?

Yes I realise that but what I meant to ask was will the power consumption of
the one sub (currently in car) stay the same when I add a second one? In
other words will the power handling per sub increase when the load's
resistance decreases.

Current doubles with parallel equivalent loads. If the two subs are
equivalent, why would one draw more than the other?

Yes I realise that but what I meant to ask was will the power consumption
of
the one sub (currently in car) stay the same when I add a second one? In
other words will the power handling per sub increase when the load's
resistance decreases.

The power delivered to the sub will roughly remain the same (kinda sorta).
So I made a mistake in my original reply because I overlooked the fact that
you were adding it in parallel. So the possible increase in output could be
higher than 3dB. It's impossible to predict what the increase will actually
be, because there are many variables at play: the amplifier output impedance
prevents a doubling of power at lower impedance loads, power compression of
the speakers may actually decrease since you're slightly lowering the power
(this serves to slightly increase output compared to dumping all this extra
amplifier power into the same speaker), and acoustical issues may play a
small role in the coherence of the sound waves.

The net result? You'll gain in increase undoubtedly. How much of an
increase is not always easy to determine.

The power handling of the sub will obviously not change though. I'm not
sure where you were going with that.

pil wrote:
I am running one 8-ohm 10" sub off a bridged amp which supplies 300W rms. I
will be adding a second identical 10" sub and will wire it in parallel to
create a 4-ohm load.

At the moment the one sub performs nice and produces good sounding bass but
it is not loud enough.

Your amplifier is rated at 300 w RMS into a 4 ohm load (presumably, but
some manufacturers will give a 2 ohm rating) You're running it into an
8 ohm load, so you're getting 150 w RMS.


How big will the difference be when I add the second
sub?

Adding a second 8 ohm sub in parallel will reduce the total impedance to
4 ohms, and your amp will put out the full 300 w RMS. This in and of
itself won't actually make your system any louder. The second speaker
itself - a second moving surface - will add 3 db of output, which is an
acoustic doubling volume. However, with how humans perceive sound, don't
expect your system to sound twice as loud.

Will the one currently in the car perform better when the load becomes
4-ohm?

No, it won't sound any differently. But the two woofers together will
sound different.

resistors in parallel = current dividers but I can't seem to figure
out wheter the sub thats in there at the moment will use more current.

No. It'll use the same amount of current as before, provided it's
available (your current will be divided among the two subs).

My amp has a 12dB bass boost at 45Hz. Can I use this on these subs? I
am afraid that it will damage the subs.

Not unless you play your amp to the point where it puts out distortion,
or if your box is improperly matched to the speaker.

Output power of amp when bridged = 300W rms. Subs is rated 175W
nominal and 350W max.

You can generally ignore subwoofer power ratings. I've driven 100 W subs
of 1000 watt amps. The way they come up with these power ratings is
unrelated to real world conditions.

--
thelizman "I didn't steal the FAQ either"

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
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This post is Copyright (C) 2004. Reproduction of its content anywhere
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is forbidden.

So youre adding a second 10" sub and dropping the impedence from 8 to 4
ohms. Esentially increasing the wattage and doubling the cone displacement.
IMHO there should be a noticeable difference. Take the time to design an
adequate enclosure and you will be rewarded.

Your bass boost wont damage the subs as long as the subs capacity is not
exceeded. So turn on the boost but turn down the amplifier gain initially,
and get a feel for the systems capacity. Adjust the gains to where it
sounds good but does not overdrive the subs or clip the amp signal.

Good Luck!!
Garrett


"pil" wrote in message
...
I am running one 8-ohm 10" sub off a bridged amp which supplies 300W rms.
I
will be adding a second identical 10" sub and will wire it in parallel to
create a 4-ohm load.

At the moment the one sub performs nice and produces good sounding bass
but
it is not loud enough. How big will the difference be when I add the
second
sub? Will the one currently in the car perform better when the load
becomes
4-ohm? resistors in parallel = current dividers but I can't seem to figure
out wheter the sub thats in there at the moment will use more current.

My amp has a 12dB bass boost at 45Hz. Can I use this on these subs? I am
afraid that it will damage the subs.

Output power of amp when bridged = 300W rms. Subs is rated 175W nominal
and
350W max.

Thank you