DVC Woofer- Does series vs parallel alter T/S parameters?
 

Folks,

Say you have a dual voice coil woofer's T/S parameters. Do the parameters change if you wire the 2 voice coils in series OR parallel?

If they change, is there anyway to calculate the new parameters? Say the woofer's T/S parameters are given by the manufacturer in 8 ohms (dual 4 ohm wired in series). Any way to calculate or approximate the T/S if run at 2 ohms in parallel?

Thanks
Kris

PS. This is my first post so... Hi Everyone :)

Re, Le, and BL all change as you swap wiring modes. However, the changes are complementary, so the effective Qes (and thus Qts) of the driver stays the same.

In short, don't sweat it - it changes, but the changes cancel each other out.

Dan Wiggins
Adire Audio

If I understand things correctly, the low end response should stay the same whether wired in parallel or series since as Dan states the T/S changes are complementary.

However, I believe the high frequency extension is increased in parallel configuration as that lowers inductance, which directly affects the high end response.

Sound right Dan?

Great. Thank you very much Dan!

Not quite...;) The rolloff corner frequency is the classic RL first order filter; thus if you double L and double R at the same time, you end up with a higher cutoff frequency.

Wiring in parallel or series will not change the roll-off; R will quadruple when moving from parallel to series. Likewise L quadruples when moving from parallel to series (number of turns doubles, thus inductance, which goes as the square of the number of turns, quadruples).

Things only get weird for a DVC driver when you actively drive one voice coil.

Dan Wiggins
Adire Audio

Ah... good to know. Thanks for the clarification Dan.

Re: DVC Woofer- Does series vs parallel alter T/S parameters?
 

If you play with WinISD or something else and you want to enter all the parameters that you want to use directly you can for example:

In Series (8 ohms):

BL = 10 NA (BL is two times bigger than in parallel)
Re = 6,4 ohms (Re is four times bigger than in parallel)
Le = 3,2 mH (Le is four times bigger than in parallel)

In Parallel (2 ohms):

BL = 5 NA (BL is two times smaller than in series)
Re = 1,6 ohms (Re is four times smaller than in series)
Le = 0,8 mH (Le is four times smaller than in series)

Good luck!

Well, the main T/S parameters don't change, but the voltage sensitivity is different by 6dB.

Yes but the efficiency in dB per watt is the same.

Lots of great input, thank you.

My concern are with the parameters associated with building an enclosure. I am trying to select a speaker for use in a bandpass application. This particular speaker (Kicker Solobaric) is available in 2 ohm per voice coil. I have not determined which amp I will be using yet. I have an amp that is 1/2 ohm stable (Soundstream Reference 405S) which I would then run the voice coils in parallel for 1 ohm. I also have an amp that is 2 ohm stable (Soundstream USA 305) then I would run them in series for 4 ohms.

I just want to make sure that the box I build will be correct for either wiring senario.

Thanks Again!!