Thread: How do I hook these items up properly

Power handling is also limited by the wire itself used for the voice coil.

I'm not going to debate (sorry) as I'm no expert and this is not the thread to debate it in.(thread jack ). I know this has been discussed at the12volt.

In the end, I still suggest to the OP what I suggested. If he wants to get rid of his extra sub and buy a box to try a questionably sketchy setup... Be my guest, I wouldn't.

well my thoughts are is that it would help increase power handling by that particular voice coil a little bit because it can use the second coil as a heatsink, but, I don't think the coil can handle as much power as both coils together. Say if it is a 400 watt DVC sub, if you connect both coils then each coil will be accepting 200 watts each as their limit. In theory if you connect one coil the other one would act as a heat sink and enhance its own power handling capabilities. I don't expect it to be 100% efficient so therefore it'll only be increased to say 300watts or so.

So yes, my opinion yes it will decrease the power handling you could get from DVC but not decrease it as much as by half.

but when you connect the coils in series, all 400w of the power is required to flow through both coils.

back to my last point-- what limits any wire from taking a certain amount of power? how effectively it can get rid of any heat that power creates while running through the wire length. all subs have a pretty extensive cooling system built in, which is what allows them to have power in the hundreds of watts flowing through a small 22-24ga wire.


the other aspect of this is distortion. as many in car audio know, distortion kills speakers.

distortion, in 'simple' terms(distortion is not simple), is power that the speaker can't use. either because that power is being applied when the sub is extending past it's mechanical movement, or the power is being applied in way that the sub can't do anything with the electrical signal the distortion is implying it should do. so this power needs to go somewhere, and it does. it gets converted to heat.

how well the speaker gets rid of this heat is related to it's power handling. everything is related .

all of my speakers use amps whose RMS output values are at least double of the speakers RMS values. i have also never blown a speaker(at least in my car. i have blown speakers intentionally in my work shop). because i keep audible distortion away from the speakers-- either by turning it down, or adjusting the crossover points to avoid frequencies outside of the speakers limits at that volume..

Originally Posted by soundman98

(you know, i've been waiting for someone to debate on this issue )

You fool! You must have thought I'd not revisit this thread...
Well, to quote Australian foreplay - brace yourself!
But not quite - I can only talk from the simple theoretical POV.


What limits the power?
- the power the speaker can handle (heat; wire fusing)
- the power the amp can supply. This is based on speaker impedance (resistance) - eg, a 200W "stable at (a minimum of) 2 Ohm" should put 100W into a 4 Ohm speaker, and blow up into a 1 Ohm speaker.

From here I'll use "R" for Ohms - ie, 1R means 1 Ohm. That's a common substitution and overcomes the html etc problem where the normal Ohm's "omega" symbol (Ω) is displayed as W. (Which is most confusing because a 1W resistor is as legitimate as a 1Ω resistor. In retrospect, some of those authors were not idiots after all!)


Power can be varied by changing speaker resistance - eg, series or parallel connection. EG, Four 2R 100W speakers in series-parallel as a 2R 400W load.

If speakers are the same, combinations are easy...
EG - 2R in series = 4R, 6R, 8R (for 4 in series) etc. (Addition of resistances.)
EG - 2R in parallel = 1R (2R/2), 4 in parallel = 2R/4 = 0.5R etc.


And yes, resistance increases with temperature.
Hence it makes more sense to split between 2 VCs provided the parallel connection does not exceed the amp's minimum output resistance. (Series connection at least halves the power.)
But the latter is IMO simply a case of max power into the lowest resistance. You wouldn't add 1 or 3 extra speakers (for the same resistance using the 2 paralleled "2 in series" method) for that slight power gain.


Then there is the efficiency.
Will 1W into a 100W speaker be louder than into a 1W or 10W speaker? IE - should the amp and speaker be reasonably matched because 1W isn't enough to move a 100W speaker?
That's one for the audio gurus, but I see how cone stiffness and maybe magnetic hysteresis etc do effect that.
Plus simply - why should a 1W signal have to "push" the extra copper and core (weight) required to handle 100W etc?



IMO the above cover the basics. From that comes the (later) clarity - eg, A VC may produce 100W of heat... each VC - across the same source - produces the same heat, hence a total of 200W if in parallel. (And only 50W total if in series.)


And yes, the12volt.com is IMHO often great site for this type of info.
However, having recently wasted effort because someone butted in with "RMS Power in audio is a misnomer" and seemed to infer that "Continuous Power" was somehow - or significantly - different... Let's just say I was not amused. I found myself in the same situation as many others - trying to find valid info on the web! Ha!! (Information increases exponentially. Since bad info is more common than good, the chances of hitting good info decreases with time. And boy oh boy have I noticed that decrease recently!!)



PS... Heat varies with the square of the current OR voltage.
EG = P = IIR = VV/R. So for a constant Resistance, power (heat) is proportional to I x I, or V x V.
So double the current means four times the power/heat.

Originally Posted by OldSpark

You fool! You must have thought I'd not revisit this thread...

TBH, i didn't even think of it...

Originally Posted by OldSpark

Then there is the efficiency.
Will 1W into a 100W speaker be louder than into a 1W or 10W speaker? IE - should the amp and speaker be reasonably matched because 1W isn't enough to move a 100W speaker?
That's one for the audio gurus, but I see how cone stiffness and maybe magnetic hysteresis etc do effect that.
Plus simply - why should a 1W signal have to "push" the extra copper and core (weight) required to handle 100W etc?

in the older days, they used to list the loudness of each speaker at 1watt, with the mic 1 meter away (87db @ 1w/1m). i believe they still do it, but it plays less of significance in speaker selection then it used to.

and while that number can accurately portray the speakers sensitivity to low power inputs, it doesn't as accurately show the speakers tonal characteristics, which might have been why that number has since taken a back-seat while selecting speakers.

Originally Posted by OldSpark

However, having recently wasted effort because someone butted in with "RMS Power in audio is a misnomer" and seemed to infer that "Continuous Power" was somehow - or significantly - different... Let's just say I was not amused. I found myself in the same situation as many others - trying to find valid info on the web! Ha!! (Information increases exponentially. Since bad info is more common than good, the chances of hitting good info decreases with time. And boy oh boy have I noticed that decrease recently!!)

i can see how that debate could have some ground, though a little shaky.. being that RMS is Root Mean Square, and i believe they derive that number using the sometimes-fraudulent-maximum wattage rating of a driver, i can see how some would prefer to see a 'continuous power' rating over RMS...

To Be Honest? When does that enter into one of MY debates?!!


Yeah - I remember the dB@power&distance, though I took that to be at whatever wattage - typically the nominal or rated Wattage - though expressed as a per Watt measure. It wasn't the sensitivity at low power - eg, 1W - it was supposed to give an indication of "loudness" at typical powers. But the spread played its part - eg, whether measured 2D or 3D (in a plane, or "around"), or if the speaker was fairly directional. (And hence frequency played its part...)

Of course I may be wrong. I am speakering from a general POV, not specific design involvement.



And the latter "general POV" is a great segway into the last bit...
I would not have minded if the Continuous Power "discussion" (NOT!) was about misleading or misunderstood specs etc.
But is was simply a statement that quoted Rane (namely: "rms power - No such thing. A misnomer, or application of a wrong name. There is no such thing as "rms power" ...." as if that were somehow significant, or in fact a valid reference etc. (See under rane/par-r)
Anyhow, my conclusion after understanding three main definitions for "Continuous Power" was that Rane simply referred to the technicality that - strictly speaking - "RMS Power" is not "an RMS power", but an "average power". IE - the so called "RMS Power" is calculated using RMS values of voltage and current, but it is not itself an RMS value.

Now I won't get into "Vrms x Irms" which is a VA rating (Watts divided by Power Factor) or the vectorial or complex etc product of (V x I)rms where only voltages and currents at the same frequency produce "real" power, and how people may use "RMS" for both or "RMS" to mean "real" power...
That IMO is where each discussion needs to define how it will use a particular term.
I simply thought that the original statement served no useful purpose, and worst of all, it took away any enjoyment from my CAP pun/joke. (The OP using the term Continuous Audio Power or CAP, to which I responded something like "I hate all CAPs!".)

I had two main conclusions:
- any difference between CAP & RMS Power is probably negligible (if it can be measured in any useful way),
- the whole exercise was useless considering the 3rd person involved admitted to testing amplifiers using RESISTORS! Considering a typical speaker can vary its resistance by 2:1 over its specified frequency range, that makes a complete joke of any that "RMS" statement. Not to mention the impact speaker & amp impedances on frequency response etc.


Otherwise it enforced other trivial conclusions - eg, there are always BES-type people that try to transfer blame or attack others when they realise they were wrong (BES actually going to the trouble of removing her incriminating posts - something that can't be done on the12volt), and that it is increasingly difficult to get valid info off the web. (Original edition hardcopies are gonna be worth a fortune!! Or be illegal.)
The fact that I found 3 "definitions" for Continuous Power is testament to that.
The fact that these involved reactive power or "non-sinusoid" power is far worse...

I thought it may have been as you alluded - fraudulent Wattage claims.
But I see that as a spec issue. RMS cannot be rigged unlike "peak" etc, but it is subject to duration and program content.
Those conditions should be stated if they are not in accordance with standards etc - eg, for 1 or 8 hours on a hot day up a mountain.

RMS is implicitly a long-term spec. Or rather, it is NOT a "short-term" spec.
IMO anyone that sells a 100W audio amp as 300W (RMS!) because it can handle 300W for a few minutes before failing is in for trouble. (They would be under Australian Law.)
Besides, that's where MTTF or MTBF comes in (ie, Mean failure Times at stated/spec's performance levels).


That CAP exercise was amusing because IMO it showed how certain so called experienced or experts or litols lack comprehension or thinking abilities. (The aforementioned once stated what rubbish specs were - they couldn't see that they were merely "the simplified one-liner" type of spec.)

The other amusement was that whilst I counted 3 reasonably different definitions, my conclusion was not based on ANY of them.... LOL.
(Typical me, I find the problem is not as discussed, but often something far more fundamental, or general.)