How bad is running a dual voice coil subwoofer with stereo amp?

[partyface86]

crossed over in the 60-70 hertz range will work. I think 80hz is the dolby standard for Home theater. If you have a crossover: can you run a high pass to your mains? If they are two- way; and your sub big enough to work alone, you will get improved midrange performance by taking the deep bass out of the program material and more cohesive bass since it will be single source.

My speakers are 2 way but I don`t have the option to run it on highpass.

with a 4th order crossover (why would someone use anything else ;-) @40hz. ; the bass would be attenuated 40db or so at 20hz . I also eluded to a suggestion of an 80hz crossover point. And yes the satellites would be playing mid-bass. I recommend 80hz so that the crossover frequency is not center on the kick drum fundamental of approximately 60hz.. Bass guitar lowest note is 40hz. only piano , synth and effects play lower.

thanks for the suggestion 😉

 

[partyface86]

A DVC will DEFINITELY sound different if you leave one of its coils disconnected. Qes and therefore Qts will be increased.

Is there any sound difference between running the coils in paralel or series?

 

[AndrewT]

parallel presents a much lower impedance to the amplifier and results in avoidable amplifier distortion as well as the risk of overheating.

dual 4ohm in series gives a conventional 8ohms loading for the amp, much easier than 2ohms for paralleled operation.

If it is a dual 2ohms, then don't even consider paralleled operation.

 

[partyface86]

If it is a dual 2ohms, then don't even consider paralleled operation.

I wasn`t considering as the amp accepts only 6 ohm loads minimum. I am just wondering if the bass response is different with parallel vs series

 

[AndrewT]

The bass response does not change.

 

[bentoronto]

Todd Welti of Harman did a careful* JASA study of stereo subs. Haven't been able to see it. I hope somebody can give us all a link to the full text.

Ben
*beats me why those Harman guys use pop vocalists' recordings and not much else, at least in other studies.

 

[JMFahey]

As far as a DVC is concerned, it won't make a difference. The output is the sum of both signals anyway.

And that's the point, it WILL make a BIG difference.

If I sum different signals, it's much better to do so at a signal level than at a power level.

Just an extreme example, but to make things clear without much math applied.

Suppose that at a certain frequency, 2 signals are the same voltage but exactly 180* out of phase.

Happens all the time when live recording (hint: standard program material) when, say, 2 microphones are picking an orchestra and path divergence from, say, a violin to them is 1/2 halfwave .

In a signal mixer both , say, 1V RMS signals will cancel, period, and nothing bad will happen, specially to speaker.

Now you apply same 2 signals, same level but now 100W each, still out of phase: you'll have a speaker which does not move at all, which produces no sound, yet mysteriously goes up in flames.

This is admittedly an extreme example, proposed for clarity of concept, but to show that it's very poor Engineering to apply different signals to twin coils wound on the same former and "let the speaker deal with it" .

That's why proper way to do it is to first mix both signals into Mono.