[D OB G]

I posted this question on DiyAudio without a single response!   
What are the issues with Le?
Is a higher Le OK with, say, a subwoofer driver?
Is the major issue higher IM distortion with higher Le?
If so, would restricting a driver to a narrow pass band help the situation?

David

[Bemopti123]

I am curious, can you post a link and a picture of some builds?

[Graham Maynard]

Hi David,

Yes I saw your original post.

'Le' is more relevant for mid and especially high frequency transduction, but your question does not suggest to any possible respondent what information you are looking for or why. 

Anything in particular you have in mind ?

Cheers ...... Graham.

[D OB G]

It's just a general enquiry into one of the loudspeaker parameters- looking for a detailed response!
I have some subwoofer drivers with one of the highest Les I have seen (4mH).
I wonder what correlation would be expected with performance. Is there any relevance for a woofer?
On the other hand, all other things being equal, Freq. response e.t.c, what is the correlation of the performance of higher frequency drivers, tweeters e.t.c, with Le?
Is there an issue with impulse response, or, as I have seen referred to somewhere, IM distortion?
Any information would be appreciated.

David

[iON]

Hi David,

As you might already know Le is the inductance of the loudspeaker. The voice coils is after all ... a coil. For example this value has impact on the impendance and the phase of the speaker. The value of Le is not related to quality though, as I see it it's just another parameter. Actually, many simpler simulation programs doesn't even bother taking Le into the equation.

/J

[Graham Maynard]

Hi iON,

Good point about simulation software not taking voice coil impedance into consideration !  Plots do not take account of the considerable transduction current phase change with respect to waveform voltage, but then I suppose non-musical sine SPL is often the main wanted specification anyway !

Hi D OB G,

4mH is fine for genuine subwoofers with long overhung voice coils.  I have one 15" here with double voice coils of 4ohms and 3.9mH each.  About 75Hz seems to be its upper reproduction limit - where it needs to hand over to more coherently transducing 12 or 10 inchers.  Actually it is best running no higher than 50Hz.  What a small bandwidth, but it does shift some air !

At the other end of the spectrum few genuinely HF capable tweeters exceed 100uH, with some in the region of 10uH. Generally, the lower the inductance the more discriminating the HF response, though here the impedance alone cannot be directly correlated with the musicality of reproduction.

Cheers ........... Graham.

[rick57]

This may help

http://www.linkwitzlab.com/frontiers_3.htm#P

Cheers