Subwoofers in Series?
 

Can someone explain to me why it is unadvisable to wire multiple subwoofers in series?
JL Audio's website says to avoid it at all costs, but my simple mind can't figure out why....

cuz u get less poundage that way, duuuhhhhhhh

honestly no clue

the only thing I can think of it that by connecting multiple speakers in series to 1 Ch. of an amplifier you affectively raise the impedance, and it's my understanding that most amps have a ceiling around 16 ohms.

:dunno:

Mark

that is an odd recommendation. If you have 4x 4ohm subs and an amp that cannot handle 2 omhs, then you put 2 pair in series tomake 2 8ohm double subs and then those 2 in parallel to bring it back down to 4 ohms. You could accomplish exactly the same thing if you had a pair of double voice coil 4+4 ohm subs. The 4+4 ohm voice coil in series = 8ohms..then put the two 8ohm subs inparallel to make 4 ohms again. Or you could put the 4+4 ohm voice coils in parallel to make 2 ohms, and then these 2 2ohm subs insereis tomake 4 ohms again.

There is reduced damping factor for the subs however, since the sub in each series pair sees the 4ohm impedance of the other sub, and not just the very low (under 1 ohm) output impedance of the amp.
That may be why JL says so and I could agree with that reason.

There is no chance to dammage the subs or the amp if you do that.

It's my understanding that JL only states that for SVC drivers, as they don't have any problems wiring in series from VC to VC on the same driver..

Mark

Can you show a link? ... I'd be interesting in seeing this. :smilie_da

thinking about it a bit more..
when a coil moves in a magnetic field, it is a generator..
so a voice coil moving thru the magnetic field does create a back voltage (or emf electromotive force). DVC subs have identical voice coils and this back emf is evened out.
However putting subs in series, with different enclosures, different size subs, or simply identical subs that differ only in manufacturing tolerances could interfere with each other because of this back emf...
...So along with my moral code not to comment on anything I dont know about or cannot back up...I will reseach this and even ask JL....
Will report back...

JL Audio

Please note that when wiring multiple drivers it is recommended that series connections between drivers be avoided at all costs. This does not include series connections made between voice coils on the same driver. For more information, please consult our dual voice coil tutorial section.

regards, Mark

Excellent... I'm going to post this on another forum that Manville Smith posts on... maybe we can get some answers from him :smilie_da

quick search with google, and hit on this...

It is not suggested that you run speakers in series. No two speakers will be exactly identical, even if they are the same model from the same manufacturer. This means that they will act slightly different from each other when presented with the same input signal. When wired in series, these differences will cause distortion in the form of back EMF.
You can however run both coils of a DVC speaker in series. The cone movement for both coils will be identical, and will not cause distortion problems. This is the formula to calculate the impedance of speakers in series.

Mark