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MOSFET MOSFET is offline
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Posts: 810
Default Dual Voice Coil Question

I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel but
that would be a 1 ohm load and I KNOW from experience I could damage the
amp). They are connected now so that my amp sees a 4 ohm load (through a
combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts in
the past, the coils overlap each other on the former so I was thinking that
by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power produced
by a 2 ohm load exceed the benefits of having both coils connected.

Any information on this subject would be appreciated.

MOSFET


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SKaReCRoW SKaReCRoW is offline
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Posts: 8
Default Dual Voice Coil Question

I wouldn't even suggest you try it. Best case scenario is you can only give
the subs 1/2 of the power.

"A common misconception with regard to dual voice coil speakers is the
assumption that nothing changes if you power only one of the voice coils.
With only one coil hooked up, a dual voice coil speaker will suffer a loss
in reference efficiency of about 3dB (only half the coil windings are being
energized) as well as a significant shift in its Thiele/Small parameters.
This renders any enclosure calculations inaccurate unless you remeasure the
speakers parameters with only one coil hooked up. Failure to account for the
different parameters of a dual voice coil speaker with only one coil powered
can result in very poor performance."

Above quote is taken directly from JL Audio's website at
http://mobile.jlaudio.com/support_pages.php?page_id=163

So would it be worth it to you to get more power to subs that can handle
less, and are 3dB less efficient? I'd bet not.

"MOSFET" wrote in message
m...
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel
but that would be a 1 ohm load and I KNOW from experience I could damage
the amp). They are connected now so that my amp sees a 4 ohm load
(through a combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts in
the past, the coils overlap each other on the former so I was thinking
that by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power
produced by a 2 ohm load exceed the benefits of having both coils
connected.

Any information on this subject would be appreciated.

MOSFET



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SKaReCRoW SKaReCRoW is offline
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Posts: 8
Default Dual Voice Coil Question

Almost forgot to mention you'll get more distortion from the amp. So more
power with more distortion to subs that will handle half the power and are
less efficient. Any chance you can return those subs for a pair of 4ohm
SVC's or 2ohm DVC's?

"SKaReCRoW" skarecrowatatgmaildotcomdotcom wrote in message
m...
I wouldn't even suggest you try it. Best case scenario is you can only
give the subs 1/2 of the power.

"A common misconception with regard to dual voice coil speakers is the
assumption that nothing changes if you power only one of the voice coils.
With only one coil hooked up, a dual voice coil speaker will suffer a loss
in reference efficiency of about 3dB (only half the coil windings are
being energized) as well as a significant shift in its Thiele/Small
parameters. This renders any enclosure calculations inaccurate unless you
remeasure the speakers parameters with only one coil hooked up. Failure to
account for the different parameters of a dual voice coil speaker with
only one coil powered can result in very poor performance."

Above quote is taken directly from JL Audio's website at
http://mobile.jlaudio.com/support_pages.php?page_id=163

So would it be worth it to you to get more power to subs that can handle
less, and are 3dB less efficient? I'd bet not.

"MOSFET" wrote in message
m...
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel
but that would be a 1 ohm load and I KNOW from experience I could damage
the amp). They are connected now so that my amp sees a 4 ohm load
(through a combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm
load and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts
in the past, the coils overlap each other on the former so I was thinking
that by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power
produced by a 2 ohm load exceed the benefits of having both coils
connected.

Any information on this subject would be appreciated.

MOSFET





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GregS[_3_] GregS[_3_] is offline
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Posts: 664
Default Dual Voice Coil Question

In article , "SKaReCRoW" skarecrowatatgmaildotcomdotcom wrote:
I wouldn't even suggest you try it. Best case scenario is you can only give
the subs 1/2 of the power.

"A common misconception with regard to dual voice coil speakers is the
assumption that nothing changes if you power only one of the voice coils.
With only one coil hooked up, a dual voice coil speaker will suffer a loss
in reference efficiency of about 3dB (only half the coil windings are being
energized) as well as a significant shift in its Thiele/Small parameters.
This renders any enclosure calculations inaccurate unless you remeasure the
speakers parameters with only one coil hooked up. Failure to account for the
different parameters of a dual voice coil speaker with only one coil powered
can result in very poor performance."

Above quote is taken directly from JL Audio's website at
http://mobile.jlaudio.com/support_pages.php?page_id=163


Sometimes things are done with the other coil for some crazy reasons. I know I
could find a reference in my 20 year reading Speaker Builder magazine. I just
wanted to say, you would be able to drive the single coil with more than 1/2 rated
power since overall heat is basically in the same place.

Only using one coil will almost certainly require a larger box to compensate for
decreasing Qts.

greg


So would it be worth it to you to get more power to subs that can handle
less, and are 3dB less efficient? I'd bet not.

"MOSFET" wrote in message
om...
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel
but that would be a 1 ohm load and I KNOW from experience I could damage
the amp). They are connected now so that my amp sees a 4 ohm load
(through a combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts in
the past, the coils overlap each other on the former so I was thinking
that by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power
produced by a 2 ohm load exceed the benefits of having both coils
connected.

Any information on this subject would be appreciated.

MOSFET



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Mister.Lull Mister.Lull is offline
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Posts: 143
Default Dual Voice Coil Question

....Hmmm.

All good points (from the other posters).

However, my first question would be: What are the subs rated at?

I'll be the first to admit that I've never tried it, but if they're
rated to handle 1000W RMS @ 2-ohms each, then you might as well wire
it up the way you're suggesting based on the fact that your amp
wouldn't power them all the way anyhow.

I dunno - seems to me like you've got yourself an excuse to help out
our down economy by going out and getting a 1-ohm stable Class D
Amplifier...

}:-)
~Mister.Lull

On Feb 1, 8:12*pm, "MOSFET" wrote:
I will start by saying the obvious answer to my question is to "just try
it". *But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. *They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel but
that would be a 1 ohm load and I KNOW from experience I could damage the
amp). *They are connected now so that my amp sees a 4 ohm load (through a
combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. *As I recall from posts in
the past, the coils overlap each other on the former so I was thinking that
by doing this I wouldn't lose excursion. *Or would I?

Basically, my question boils down to this; does the increased power produced
by a 2 ohm load exceed the benefits of having both coils connected.

Any information on this subject would be appreciated.

MOSFET



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MOSFET MOSFET is offline
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Posts: 810
Default Dual Voice Coil Question

Thanks for the advice. I appreciate it.
MOSFET

"SKaReCRoW" skarecrowatatgmaildotcomdotcom wrote in message
m...
Almost forgot to mention you'll get more distortion from the amp. So more
power with more distortion to subs that will handle half the power and are
less efficient. Any chance you can return those subs for a pair of 4ohm
SVC's or 2ohm DVC's?

"SKaReCRoW" skarecrowatatgmaildotcomdotcom wrote in message
m...
I wouldn't even suggest you try it. Best case scenario is you can only
give the subs 1/2 of the power.

"A common misconception with regard to dual voice coil speakers is the
assumption that nothing changes if you power only one of the voice

coils.
With only one coil hooked up, a dual voice coil speaker will suffer a

loss
in reference efficiency of about 3dB (only half the coil windings are
being energized) as well as a significant shift in its Thiele/Small
parameters. This renders any enclosure calculations inaccurate unless

you
remeasure the speakers parameters with only one coil hooked up. Failure

to
account for the different parameters of a dual voice coil speaker with
only one coil powered can result in very poor performance."

Above quote is taken directly from JL Audio's website at
http://mobile.jlaudio.com/support_pages.php?page_id=163

So would it be worth it to you to get more power to subs that can handle
less, and are 3dB less efficient? I'd bet not.

"MOSFET" wrote in message
m...
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They

are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the

four
voice coils to reach a 2 ohm load (I could connect all four in parellel
but that would be a 1 ohm load and I KNOW from experience I could

damage
the amp). They are connected now so that my amp sees a 4 ohm load
(through a combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm
load and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts
in the past, the coils overlap each other on the former so I was

thinking
that by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power
produced by a 2 ohm load exceed the benefits of having both coils
connected.

Any information on this subject would be appreciated.

MOSFET







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MOSFET MOSFET is offline
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Posts: 810
Default Dual Voice Coil Question

Thanks greg.
Nick
"GregS" wrote in message
...
In article , "SKaReCRoW"

skarecrowatatgmaildotcomdotcom wrote:
I wouldn't even suggest you try it. Best case scenario is you can only

give
the subs 1/2 of the power.

"A common misconception with regard to dual voice coil speakers is the
assumption that nothing changes if you power only one of the voice coils.
With only one coil hooked up, a dual voice coil speaker will suffer a

loss
in reference efficiency of about 3dB (only half the coil windings are

being
energized) as well as a significant shift in its Thiele/Small parameters.
This renders any enclosure calculations inaccurate unless you remeasure

the
speakers parameters with only one coil hooked up. Failure to account for

the
different parameters of a dual voice coil speaker with only one coil

powered
can result in very poor performance."

Above quote is taken directly from JL Audio's website at
http://mobile.jlaudio.com/support_pages.php?page_id=163


Sometimes things are done with the other coil for some crazy reasons. I

know I
could find a reference in my 20 year reading Speaker Builder magazine. I

just
wanted to say, you would be able to drive the single coil with more than

1/2 rated
power since overall heat is basically in the same place.

Only using one coil will almost certainly require a larger box to

compensate for
decreasing Qts.

greg


So would it be worth it to you to get more power to subs that can handle
less, and are 3dB less efficient? I'd bet not.

"MOSFET" wrote in message
om...
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They

are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the

four
voice coils to reach a 2 ohm load (I could connect all four in parellel
but that would be a 1 ohm load and I KNOW from experience I could

damage
the amp). They are connected now so that my amp sees a 4 ohm load
(through a combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm

load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts

in
the past, the coils overlap each other on the former so I was thinking
that by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power
produced by a 2 ohm load exceed the benefits of having both coils
connected.

Any information on this subject would be appreciated.

MOSFET





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MOSFET MOSFET is offline
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Posts: 810
Default Dual Voice Coil Question

That's a good question. They are not all that powerful. Only 400 watts
RMS, 900 watts max. I guess you would cut that in half by using only one of
the two coils. I suppose if that were the case, I could damage my subs by
overpowering them.

Thanks Lull,
Nick

"Mister.Lull" wrote in message
...
....Hmmm.

All good points (from the other posters).

However, my first question would be: What are the subs rated at?

I'll be the first to admit that I've never tried it, but if they're
rated to handle 1000W RMS @ 2-ohms each, then you might as well wire
it up the way you're suggesting based on the fact that your amp
wouldn't power them all the way anyhow.

I dunno - seems to me like you've got yourself an excuse to help out
our down economy by going out and getting a 1-ohm stable Class D
Amplifier...

}:-)
~Mister.Lull

On Feb 1, 8:12 pm, "MOSFET" wrote:
I will start by saying the obvious answer to my question is to "just try
it". But in the interest of educating myself, I would appreciate some
information.

I recently bought 2 15" subs, each has dual 4 ohm voice coils. They are
both being driven by an Alpine Class D 850 watt amp (MRV-850, I think).
This mono amp is 2 ohm stable, yet there is no way to configure the four
voice coils to reach a 2 ohm load (I could connect all four in parellel

but
that would be a 1 ohm load and I KNOW from experience I could damage the
amp). They are connected now so that my amp sees a 4 ohm load (through a
combination of parellel and series wiring).

The question I have is regarding the possibility of connecting just one
voice coil from each sub and wiring that to my amp, giving me a 2 ohm load
and more power from my amp.

HOWEVER, undoutedly there is a cost to doing this, like my subs become
capable of handling 1/2 the power they used to. As I recall from posts in
the past, the coils overlap each other on the former so I was thinking

that
by doing this I wouldn't lose excursion. Or would I?

Basically, my question boils down to this; does the increased power

produced
by a 2 ohm load exceed the benefits of having both coils connected.

Any information on this subject would be appreciated.

MOSFET



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