Crossover inductors in series ,question.

[DavidL]

Another link with measurements also............ Placement of coils in crossover networks

 

[AllenB]

Is their a theoretical difference in which way around these should be placed in series?

No. Basically as current flows through the circuit it is impeded by all the components it flows through simultaneously.

Well these were each rated 150 watt and Im using two now in series. 300W????
Amp is a conservative genuine 110 watt

Inductor ratings means..."On average, it handles being used with a 100W system". The way you use the inductor in your crossover makes a difference.

The thing with inductors: the perfect inductor doesn't consume and dissipate any power. It passes back all the energy it takes and stays cold, therefore 'Watts' has no meaning to inductors. Real inductors will lose some flux and produce some heat.

 

[raffajaffa]

Wow I have just returned to this long forgotten about thread after a few years enforced hifi absence.In which time I went thru a trial by converting to a three way system, which was interesting but it became a less efficient speaker forcing an increased power amp. (200watt per channel) (this was also problomatical)
I recently decided to revert back to two way and very quickly went back to my original 1st order bottom/2nd order top.
I had to replace the age old 2208 units (Ver1 with Ver2 )which have a theoretical better midrange which was slightly part of the original problem.
I have now fine tuned and balanced the system by ear (and test tones)
Their is a very slight resonance somewhere at the top end of the bass units performance when really driven ? I may have to solidify the inductors as suggested .This Inductor is approx .6mH . I now have the opportunity to unwind another spare .95mH inductor which has a larger diameter centre air core.Same thickness wire.
After all this time has anyone anythoughts as to whether this may be worthwhile?ie
Is it going to have higher power handling capacity.I am also hoping the slightly different DCR wont effect it.
Any kind thoughts.
Dave

 

[Tweet]

No. Basically as current flows through the circuit it is impeded by all the components it flows through simultaneously.


Inductor ratings means..."On average, it handles being used with a 100W system". The way you use the inductor in your crossover makes a difference.

The thing with inductors: the perfect inductor doesn't consume and dissipate any power. It passes back all the energy it takes and stays cold, therefore 'Watts' has no meaning to inductors. Real inductors will lose some flux and produce some heat.

Hooray ! Someone at last has finally got it right.


This is my non technical view of it........

Iron cored inductors follow a B/H curve in their magnetisation and demagnetisation, all subject to the current flowing through their windings.
Such cores also suffer from magnetic hysteresis and, the inductance does not always remain perfectly linear at higher frequencies particularly when current saturation approaches.
Eddy currents induced into the core material affects laminated cores significantly, P-cores which are similar to ferrite cores are highly resistive to this magnetic loss and as such provide much better high frequency performance than do laminated types but then, are likely to saturate more easily with heavy currents.
Laminated and P-cored inductors can produce significant levels of harmonic distortion if driven into saturation by excessive bass currents, so very low impedance loads and high signal levels together are best avoided with these core types.
Iron laminated cored inductors are better used for low frequencies (Bass), P-cores for notch filters and traps or for lower powered bass, air cored inductors particularly for midrange and tweeter filters.
Air cored inductors remain linear with frequency rise but suffer greater power loss due to their higher DC resistance, but more importantly do not produce any harmonic distortion at any level of current.

C.M

 

[PM4A]

Backwards

as part of my job i test electrical machines, and a common task is the saturation curve. From my working knowledge i would run a similar test. This is what i would do. Get a variable ac supply, take a curve of V against I, working from 1.3 times inductor current rating down to 10% rating or lower. For a real valid test, winding temp would need to be monitored also. Then the Z, this is found from the trace and plotted. Temp compensation should be employed to correct for winding heating effect. The resultant corrected plot will be linear to the point of saturation. However, ferrite cored inductors whose typical use is in SMPS supplies are rated at a level where minimal or no saturation occurs, or they would fail to fulfill their purpose. A revealing question to ask yourself is: what current peak would i expect? Decide an answer,0hen pick an inductor whose current rating exceeds that level. Then you can be fairly sure that saturation will not occur. I have used 10amp ferrites with no issue whatsoever, 3amp rated arent so good. I reckon that the core diameter and wire gauge and number of turns is very relevant though. Scale core dia to inductance. Im using 2mm wire on a 1.5 inch ferrite. Monacor 'high power' at 2.2mH. Works well. The 0.6mm 3/4inch lower power monacor ferrite in 2.2mH is ok, UNTIL you add another L in series, even just 0.22mH makes it saturate wildly. Going for 10amp rating MINIMUM will work well. Even doing this hysteresis is still present, but it is a comprimise between DCR and size and saturation as sreten was inferring. Use 1 coil if possible, be it air or ferrite cored.

 

[PM4A]

Backwards

In other words buy another decent amp and bi-amp with an RC network.



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