Dual Voice Coil Question

[MOSFET]

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

[SKaReCRoW]

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
>

[SKaReCRoW]

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
>>
>
>

[GregS[_3_]]

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
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
>>
>
>

[Mister.Lull]

....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

[MOSFET]

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
> >>
> >
> >
>
>

[MOSFET]

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
> 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
> >>
> >
> >

[MOSFET]

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