[jimbo_limited]

I know its possible to run a 4 Ohm Woofer's to run 2 ohm...

1) How do u do this On a SVC and a DVC Woofer?


2)I Know is that you need 2 subs to do this and Better to go with a Mono-Amp. Is it okay to use a 2-channel and bridge it?


3)Also, is it possible to run on 1 Ohm? If so, How?

"jimbo_limited" wrote in message
...

I know its possible to run a 4 Ohm Woofer's to run 2 ohm...

1) How do u do this On a SVC and a DVC Woofer?

to run a single 4 ohm speaker you would need a bridgeable
2 channel amp and run the single 4 ohm speaker on the bridged outputs.
On the DVC you would need one with dual 8 ohm coils, then
paralall the 2 voice coils the run it bridged.


2)I Know is that you need 2 subs to do this and Better to go with a
Mono-Amp. Is it okay to use a 2-channel and bridge it?

If the amp is bridgeable you can run a singel 4 ohm speaker
on it and the amp will run at 2 ohms


3)Also, is it possible to run on 1 Ohm? If so, How?

It's possible, but the amp must be a 1 ohm stable amp or running it at 1ohm
will cause the amp to over heat or short out the outputs and
damage the amp


--
jimbo_limited

Just wanted to add that running 1ohm bridged is nearly impossible, off the
top of my head i don't know any amp that will handle that. Mono amp would
be the way i'd go because of it handling a lower impedance and because of
the increased efficiency of a class D. If you don't care about efficiency,
go a/b.

"Matt Ion" wrote in message
news:Mg1gf.552617$tl2.435108@pd7tw3no...
jimbo_limited wrote:
I know its possible to run a 4 Ohm Woofer's to run 2 ohm... 1) How do u
do this On a SVC and a DVC Woofer?

You can't do it with a single SVC sub. This is basic Ohm's Law: two 4-ohm
loads in parallel will present a 2-ohm load to the amp. Two 4-ohm SVC
subs wired in parallel, or one 4-ohm DVC sub with the coils wired in
parallel, will achieve this.

2)I Know is that you need 2 subs to do this and Better to go with a
Mono-Amp. Is it okay to use a 2-channel and bridge it?

Sure, as long as it will handle the load. Remember that halving the
impedance of the speakers will double the current draw on the amp, and
bridging it will effectively quadruple the current it must handle. Lesser
amps may run fine with 2-ohm loads un-bridged, but not handle the current
when it is bridged, so be sure to check the specs on the amp you're using
(or the ones you're planning to buy).

3)Also, is it possible to run on 1 Ohm? If so, How?

Four 4-ohm SVC speakers wired in parallel, or two DVC drivers with their
coils wired parallel, then wired parallel with each other. Very few amps
will handle this without releasing their magic smoke.


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On Sun, 20 Nov 2005 11:22:17 -0500, "Chris Mullins"
wrote:

Just wanted to add that running 1ohm bridged is nearly impossible, off the
top of my head i don't know any amp that will handle that. Mono amp would
be the way i'd go because of it handling a lower impedance and because of
the increased efficiency of a class D. If you don't care about efficiency,
go a/b.


True. One-Ohm mono operation isn't very common, because it's simply
not as important as it used to be. Back in the eighties and early
nineties, you had people that wanted to compete in the low-wattage
classes in IASCA and USAC, but still crank out huge SPL numbers.

This led to the development of so-called "cheater amps", that had low
power ratings at four ohms, but could be safely used all the way down
to one-quarter or one-half Ohm. This meant that you could compete in
the "1-50 Watt" class, but you could be getting 400 watts or more out
of your amp by running ultra-low impedences.

If you've ever seen a "50-Watt" amp that's two feet long, weighs about
thirty pounds, has multiple cooling fans, four-gauge power inputs, an
80-amp fuse, and cost about $500 new, that's probably why.
--
Scott Gardner

"Oh look, things are going from bad to worse!"

oh also, you might want to even consider some of the (i think its called)
regulated voltage amps. They will put out the same power from 1-4ohm and
stable anywhere between. Depending on your application this could be a much
better choice. (you wouldn't have to find a way to wire the speaker to
2ohm, 4 would be just as good)


"Scott Gardner" wrote in message
...
On Sun, 20 Nov 2005 11:22:17 -0500, "Chris Mullins"
wrote:

Just wanted to add that running 1ohm bridged is nearly impossible, off the
top of my head i don't know any amp that will handle that. Mono amp would
be the way i'd go because of it handling a lower impedance and because of
the increased efficiency of a class D. If you don't care about
efficiency,
go a/b.


True. One-Ohm mono operation isn't very common, because it's simply
not as important as it used to be. Back in the eighties and early
nineties, you had people that wanted to compete in the low-wattage
classes in IASCA and USAC, but still crank out huge SPL numbers.

This led to the development of so-called "cheater amps", that had low
power ratings at four ohms, but could be safely used all the way down
to one-quarter or one-half Ohm. This meant that you could compete in
the "1-50 Watt" class, but you could be getting 400 watts or more out
of your amp by running ultra-low impedences.

If you've ever seen a "50-Watt" amp that's two feet long, weighs about
thirty pounds, has multiple cooling fans, four-gauge power inputs, an
80-amp fuse, and cost about $500 new, that's probably why.
--
Scott Gardner

"Oh look, things are going from bad to worse!"

On Sun, 20 Nov 2005 13:10:53 -0500, "Chris Mullins"
wrote:

oh also, you might want to even consider some of the (i think its called)
regulated voltage amps. They will put out the same power from 1-4ohm and
stable anywhere between. Depending on your application this could be a much
better choice. (you wouldn't have to find a way to wire the speaker to
2ohm, 4 would be just as good)


The new JL Audio amps are like that (same power into different loads).
There are also amps that may be stable at lower impedences, but don't
produce any extra power by doing so. My old PPI Art Series amps are
like this. For example, the A1200.2 puts out 1200 Watts into a 4-ohm
mono load, but if you use a three-ohm or two-ohm mono load, the amp
will work just fine, but it will reduce the output power to keep the
current at a safe level.


--
Scott Gardner

"Some mornings, it's just not worth chewing through the leather straps." (Emo Philips)

"Chris Mullins" wrote in message
...
Just wanted to add that running 1ohm bridged is nearly impossible, off the
top of my head i don't know any amp that will handle that.

Audiobahn makes several that do 1ohm bridged.

[jimbo_limited]

Thanks for the response..

I knew u needed 2 SVC Subs to run on 2 Ohms. I just wanted to be sure.


This is what I will be getting for my car audio system:

Two 12" Rockford Fosgate Punch Stage 2 Model # P212S4
Class D Monoblock Amp w/400w+ RMS or 2-channel Bridgeable (2 Ohm Stable)

or

Two 12" Rockford Fosgate Punch Stage 3 Model # P312D2
Class D Monoblock Amp w/1000w+ RMS


Reason for asking if i can wire a 4 Ohm SVC to 2 Ohm is because i want the P212S4 to run the most power i can get out of the woofers.

:-P rockford subs don't put out any power, good luck with that

p312d2-- dual 2ohm means it can run at 4 ohm or 1ohm, if you have two of
them you can run at 8,2,or 1/2 ohm each sub needs 500W

p212s4 -- single 4ohm runs at 4 ohms, if two subs, 8 or 2ohms. each sub
needs 200W

The P312d2 -- the t10001bd would match up to this perfectly, run it at 1 ohm
for two subs or 4ohms for 1 sub.


the p212s4 -- i'd go with the punch P6001bd and set my gains back a little.
Odds are with impedance rise you'll be fine.

The P312d2 would be the setup i'd go for. But more than likely you could get
a better bang/buch system elsewhere.




"jimbo_limited" wrote in message
...

Thanks for the response..

I knew u needed 2 SVC Subs to run on 2 Ohms. I just wanted to be sure.


This is what I will be getting for my car audio system:

Two 12" Rockford Fosgate Punch Stage 2 Model # P212S4
Class D Monoblock Amp w/400w+ RMS or 2-channel Bridgeable (2 Ohm
Stable)

or

Two 12" Rockford Fosgate Punch Stage 3 Model # P312D2
Class D Monoblock Amp w/1000w+ RMS


Reason for asking if i can wire a 4 Ohm SVC to 2 Ohm is because i want
the P212S4 to run the most power i can get out of the woofers.


--
jimbo_limited

Chris Mullins wrote:
:-P rockford subs don't put out any power, good luck with that

p312d2-- dual 2ohm means it can run at 4 ohm or 1ohm, if you have two of
them you can run at 8,2,or 1/2 ohm each sub needs 500W

p212s4 -- single 4ohm runs at 4 ohms, if two subs, 8 or 2ohms. each sub
needs 200W

Speakers don't "need" power, they "draw" power. The rating on a sub is
how much maximum power it can handle before melting down (actually it's
a bit more complex than that, but that's what it effectively boils down
to), not how much it "needs" or "makes".

If you put a sub rated for 200W on an amp that provides up to 500W, you
stand a better chance of blowing up the sub than if you put a 500W-rated
sub on a 200W amp (there's a whole other argument about underpowering
speakers, but we'll stay away from that for now).

And remember, amp power ratings are TYPICALLY given for four-ohm loads,
and are ostensibly a measure of the maximum power the amp CAN provide,
not how much it "pushes" out. Running multiple subs on that amp does
not "divide up" the rated power - the actual power output will depend on
the actual impedance of the load, up to the maximum available.

Example: you have an amp rated for 250W into 4 ohms. You hook up a 4
ohm sub, and with everything set at full, you'll get up to 250W out of
the amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll
get a maximum of 125W out of it. With two 4-ohm subs in parallel for a
2-ohm load, the amp will still max out at 250W. However, it will take a
lot lower input to achieve that maximum output - at a volume level that
will produce 100W output into 4 ohms, you'll get 200W into 2 ohms: the
voltage level is the same, but under Ohm's Law, with half the load,
you'll have twice the current draw, and thus twice the power consumption.

Of course, all this assumes perfect efficiency, ignores the varying
impedences a speaker presents at different frequencies, and completely
disregards the many ways amp manufacturers fudge their specs...


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Example: you have an amp rated for 250W into 4 ohms. You hook up a 4
ohm sub, and with everything set at full, you'll get up to 250W out of the
amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll get a
maximum of 125W out of it. With two 4-ohm subs in parallel for a 2-ohm
load, the amp will still max out at 250W.

umm, I don't think so...if it's a crap amp it'll die, if it's good, it WILL
give you an approximate doubling of power. It won't stay the same unless
it's specificly designed to output a certain power over varing loads; which
most amps do NOT do.




However, it will take a
lot lower input to achieve that maximum output - at a volume level that
will produce 100W output into 4 ohms, you'll get 200W into 2 ohms: the
voltage level is the same, but under Ohm's Law, with half the load, you'll
have twice the current draw, and thus twice the power consumption.

Of course, all this assumes perfect efficiency, ignores the varying
impedences a speaker presents at different frequencies, and completely
disregards the many ways amp manufacturers fudge their specs...


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spr wrote:
Example: you have an amp rated for 250W into 4 ohms. You hook up a 4
ohm sub, and with everything set at full, you'll get up to 250W out of the
amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll get a
maximum of 125W out of it. With two 4-ohm subs in parallel for a 2-ohm
load, the amp will still max out at 250W.


umm, I don't think so...if it's a crap amp it'll die, if it's good, it WILL
give you an approximate doubling of power. It won't stay the same unless
it's specificly designed to output a certain power over varing loads; which
most amps do NOT do.

Actually, you're correct... that's what I get for mulling over an answer
most of the day before finally getting to post it while I'm half-asleep


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please tell me you had another reason other than correcting me saying
"needs". What i meant was to reach the sub's full potential you'll need X
wattage. most of the time you can give a sub ****loads more power than its
rated for, but that depends on the setup and how nice you are with the
gains. For someone that doens't know much about car audio i def wouldn't
say underpowering is better than overpowering. I'd say the other way around
cause you know he'll be clipping in no time.


"Matt Ion" wrote in message
news:cixgf.567188$1i.486867@pd7tw2no...
Chris Mullins wrote:
:-P rockford subs don't put out any power, good luck with that

p312d2-- dual 2ohm means it can run at 4 ohm or 1ohm, if you have two of
them you can run at 8,2,or 1/2 ohm each sub needs 500W

p212s4 -- single 4ohm runs at 4 ohms, if two subs, 8 or 2ohms. each sub
needs 200W

Speakers don't "need" power, they "draw" power. The rating on a sub is
how much maximum power it can handle before melting down (actually it's a
bit more complex than that, but that's what it effectively boils down to),
not how much it "needs" or "makes".

If you put a sub rated for 200W on an amp that provides up to 500W, you
stand a better chance of blowing up the sub than if you put a 500W-rated
sub on a 200W amp (there's a whole other argument about underpowering
speakers, but we'll stay away from that for now).

And remember, amp power ratings are TYPICALLY given for four-ohm loads,
and are ostensibly a measure of the maximum power the amp CAN provide, not
how much it "pushes" out. Running multiple subs on that amp does not
"divide up" the rated power - the actual power output will depend on the
actual impedance of the load, up to the maximum available.

Example: you have an amp rated for 250W into 4 ohms. You hook up a 4 ohm
sub, and with everything set at full, you'll get up to 250W out of the
amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll get a
maximum of 125W out of it. With two 4-ohm subs in parallel for a 2-ohm
load, the amp will still max out at 250W. However, it will take a lot
lower input to achieve that maximum output - at a volume level that will
produce 100W output into 4 ohms, you'll get 200W into 2 ohms: the voltage
level is the same, but under Ohm's Law, with half the load, you'll have
twice the current draw, and thus twice the power consumption.

Of course, all this assumes perfect efficiency, ignores the varying
impedences a speaker presents at different frequencies, and completely
disregards the many ways amp manufacturers fudge their specs...


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In article L5Jgf.576310$tl2.455757@pd7tw3no, Matt Ion wrote:
spr wrote:
Example: you have an amp rated for 250W into 4 ohms. You hook up a 4
ohm sub, and with everything set at full, you'll get up to 250W out of the
amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll get a
maximum of 125W out of it. With two 4-ohm subs in parallel for a 2-ohm
load, the amp will still max out at 250W.


That 125 watts into two series woofers will play just as loud as 250 watts
into one, and with less distortion. The 4 ohm parallel thing, will play even louder
even with 250 watts in. There will be some variation since all the drivers usually
will not be in the same plane.

I just thought to throw that in. Some don't think about that.

greg

umm, I don't think so...if it's a crap amp it'll die, if it's good, it WILL
give you an approximate doubling of power. It won't stay the same unless
it's specificly designed to output a certain power over varing loads; which
most amps do NOT do.

Actually, you're correct... that's what I get for mulling over an answer
most of the day before finally getting to post it while I'm half-asleep


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"GregS" wrote in message
...
In article L5Jgf.576310$tl2.455757@pd7tw3no, Matt Ion
wrote:
spr wrote:
Example: you have an amp rated for 250W into 4 ohms. You hook up a 4
ohm sub, and with everything set at full, you'll get up to 250W out of
the
amp. If you hook up two 4-ohm subs in series, for 8 ohms, you'll get a
maximum of 125W out of it. With two 4-ohm subs in parallel for a 2-ohm
load, the amp will still max out at 250W.


That 125 watts into two series woofers will play just as loud as 250 watts
into one, and with less distortion. The 4 ohm parallel thing, will play
even louder
even with 250 watts in. There will be some variation since all the drivers
usually
will not be in the same plane.

I just thought to throw that in. Some don't think about that.

yeah, i think it's like +3 for doubling of subs and +6 if there in the same
plane.
greg

umm, I don't think so...if it's a crap amp it'll die, if it's good, it
WILL
give you an approximate doubling of power. It won't stay the same unless
it's specificly designed to output a certain power over varing loads;
which
most amps do NOT do.

Actually, you're correct... that's what I get for mulling over an answer
most of the day before finally getting to post it while I'm half-asleep


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Chris Mullins wrote:
please tell me you had another reason other than correcting me saying
"needs".

Yes: for the edification of all those who don't understand the difference.

What i meant was to reach the sub's full potential you'll need X
wattage.

And how do I know that?

I can't even begin to count the number of times I've heard someone
wanting a high-wattage sub because they think it's automatically louder,
or asking how much wattage a sub "makes", because they have no clue.

Be more careful with your wording if you don't want to be mistaken for
one of them.

You'll note I used poor wording in my reply, was duly chastised for it
and corrected, and I accepted that.

Surely you can do the same.


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"You'll note I used poor wording in my reply, was duly chastised for it
and corrected, and I accepted that.

Surely you can do the same."

Yes i can also note your mis-information.

And,I don't think i'll be mistaken for one of "them" since i'm not wanting a
high-wattage sub or asking what wattage a sub "makes" the first line in
the old reply was sarcasm which isn't easily transferred over text.
Mistaken for a newb that loves boss? eh you all can think i'm a
crossdressing audiobahn fan as far as i'm concerned. In the end if you
don't want to take my advice, don't, its not my equipment that will be
blown.





"Matt Ion" wrote in message
news:robhf.589401$oW2.302747@pd7tw1no...
Chris Mullins wrote:
please tell me you had another reason other than correcting me saying
"needs".

Yes: for the edification of all those who don't understand the difference.

What i meant was to reach the sub's full potential you'll need X wattage.

And how do I know that?

I can't even begin to count the number of times I've heard someone wanting
a high-wattage sub because they think it's automatically louder, or asking
how much wattage a sub "makes", because they have no clue.

Be more careful with your wording if you don't want to be mistaken for one
of them.

You'll note I used poor wording in my reply, was duly chastised for it and
corrected, and I accepted that.

Surely you can do the same.


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Mistaken for a newb that loves boss? eh you all can think i'm a
crossdressing audiobahn fan as far as i'm concerned.

ouch....an Audiobahn dig...

spr wrote:
Mistaken for a newb that loves boss? eh you all can think i'm a
crossdressing audiobahn fan as far as i'm concerned.


ouch....an Audiobahn dig...

Transvestite dig, too.


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