theory help with dual voice coil, dual driver design

[ryanosaur]

Hi.
I think I read my brain into a corner and am just stuck trying to understand what happens when you wire two DVC Drivers together in series-parallel and if you can do this from a single amp channel.

This is not about the impedance implication. I get that. (A single DVC 4 ohm Driver; in series becomes 8 ohms, in parallel becomes 2 ohms. 2 DVC 4 ohm drivers in full parallel become 1 ohm, in series parallel stays 4 ohms, and in full series would 16 ohms.)

Many diagrams I see show simply wiring each DVC Driver in series and paralleled from the Amp. (So each D4 Driver becomes 8 ohms and then the impedance is halved by paralelling the Amp signal. OK, I get that.

Alden, however, doesn't show Series-Parallel wiring like that, rather he discusses using 2 amp channels to connect the two drivers. One option being Coil(A) in Driver 1 wired in Series to a Coil(A) in Driver 2 powered from Ch1, and then Ch2 powering the other Series of Voice Coils(B) in each Driver. His other example for Parallel wiring has Ch1 powering VC(A) of Driver 1 and 2 and Ch2 powering VC(B) of each Driver.

In each of Alden's examples: Qes is halved; Vas, Sd and Pe is doubled.
In the Series example, Re and Lvc is doubled and he states that SPL will be +6dB.
In the Parallel example, Re and Lvc are halved and he states that SPL will be +12

What happens to each of those parameters with the Series Parallel wiring from a single Amp channel?
In my mind, the first set of statements hold true, re: Qes, Vas, Sd and Pe. But if Re doesn't change then it would stand to reason that Lvc wouldn't either.

Is there an SPL bump?
To me, there should be, however Dickason describes a combination of Series and Parallel wiring differently but doesn't seem to get into DVC configurations.

And so I find myself confused as to what works and why? Which should one choose for what purpose?

Any help clarifying this will be much appreciated.

Thanks!
R

 

[TLS Guy]

Hi.
I think I read my brain into a corner and am just stuck trying to understand what happens when you wire two DVC Drivers together in series-parallel and if you can do this from a single amp channel.

This is not about the impedance implication. I get that. (A single DVC 4 ohm Driver; in series becomes 8 ohms, in parallel becomes 2 ohms. 2 DVC 4 ohm drivers in full parallel become 1 ohm, in series parallel stays 4 ohms, and in full series would 16 ohms.)

Many diagrams I see show simply wiring each DVC Driver in series and paralleled from the Amp. (So each D4 Driver becomes 8 ohms and then the impedance is halved by paralelling the Amp signal. OK, I get that.

Alden, however, doesn't show Series-Parallel wiring like that, rather he discusses using 2 amp channels to connect the two drivers. One option being Coil(A) in Driver 1 wired in Series to a Coil(A) in Driver 2 powered from Ch1, and then Ch2 powering the other Series of Voice Coils(B) in each Driver. His other example for Parallel wiring has Ch1 powering VC(A) of Driver 1 and 2 and Ch2 powering VC(B) of each Driver.

In each of Alden's examples: Qes is halved; Vas, Sd and Pe is doubled.
In the Series example, Re and Lvc is doubled and he states that SPL will be +6dB.
In the Parallel example, Re and Lvc are halved and he states that SPL will be +12

What happens to each of those parameters with the Series Parallel wiring from a single Amp channel?
In my mind, the first set of statements hold true, re: Qes, Vas, Sd and Pe. But if Re doesn't change then it would stand to reason that Lvc wouldn't either.

Is there an SPL bump?
To me, there should be, however Dickason describes a combination of Series and Parallel wiring differently but doesn't seem to get into DVC configurations.

And so I find myself confused as to what works and why? Which should one choose for what purpose?

Any help clarifying this will be much appreciated.

Thanks!
R

Just wire the VC of each driver in parallel. Then each driver is 2 ohm. Now wire the drivers in series and you have the same spec as using one VC except Vas is doubled and you have an increase in spl. of 3 db for any given power input. Power handling is doubled, and obviously Sd is doubled. Qes should be the same as if you used one 4 ohm coil. Lvc will not change.

 

[ryanosaur]

Thank you.
Is there a difference in performance between wiring the VC in parallel vs series, then connecting the drivers to the amp in series or parallel, respectively?
I had seen some descriptions of this online but no description of one vs the other.

 

[TLS Guy]

Thank you.
Is there a difference in performance between wiring the VC in parallel vs series, then connecting the drivers to the amp in series or parallel, respectively?
I had seen some descriptions of this online but no description of one vs the other.

I would parallel the coils, that way the coils will act more like single coils.

 

[Eppie]

Thank you.
Is there a difference in performance between wiring the VC in parallel vs series, then connecting the drivers to the amp in series or parallel, respectively?
I had seen some descriptions of this online but no description of one vs the other.

As you mentioned, the DC resistance remains the same, but since we're talking about impedance that varies with frequency, I would expect there to be some difference as the inductance of the two voice coils will not be identical. Whether that translates to an audible difference would depend on their individual characteristics. I would not expect it to make a big difference, though, and the parallel connection on each speaker seems the most logical, as TLS Guy directed. You would need to find some impedance vs frequency graphs for the two connection methods but I guess that's where you're having trouble. Maybe give a shout out to the guys at ASR?