My Panasonic bookshelves ( with a 5 inch aramide glass fibre cone and a 25mm Semi-dome tweeter) are stated to crossover at 4.5 Khz according to the HTIB manual.
And the only components on the crossover pcb are :
2 caps : 2.2 uf and 4.7 uF metallized polyester 75V
One air core inductor. (forgot the value)
What sorta crossover is this ?? I am asking because i want to upgrade it.
I hope that this thread will get atleast one reply.
And the only components on the crossover pcb are :
2 caps : 2.2 uf and 4.7 uF metallized polyester 75V
One air core inductor. (forgot the value)
What sorta crossover is this ?? I am asking because i want to upgrade it.
I hope that this thread will get atleast one reply.
Quality in an Air Core inductor is harder to achieve than say... upgrading a cap.
It's not like it has a voltage rating. It's not a radio frequency coil, so that doesn't come into play. With Air Core, there is no permeability of the ferrite or other core material to take into account.
If it were me... I'd upgrade the caps and leave the coil alone.
It's not like it has a voltage rating. It's not a radio frequency coil, so that doesn't come into play. With Air Core, there is no permeability of the ferrite or other core material to take into account.
If it were me... I'd upgrade the caps and leave the coil alone.
An L-pad maintains the impedance IF it is properly implimented with a known load impedance. If you design for an 8 ohm load and your tweter is 4 ohms, you'll move the crossover point.
That said, given that these are not state of the art speakers, you may find the results acceptable adding some resitance in series with the tweeter - skip the L-pad and just add 0R47 - 1R47 in series. This will raise the XO point, but it will probably help the tweeter.
You can buy a pair of cheap 5W power resistors (2 each 0R47 and 1R ) to test the idea - try one, the other and both in series to find the correct attenuation (0R47, 1R, 1R47). If you want you can then buy the correct value non inductive resitors (Not that I think you'd hear the difference in this application).
That said, given that these are not state of the art speakers, you may find the results acceptable adding some resitance in series with the tweeter - skip the L-pad and just add 0R47 - 1R47 in series. This will raise the XO point, but it will probably help the tweeter.
You can buy a pair of cheap 5W power resistors (2 each 0R47 and 1R ) to test the idea - try one, the other and both in series to find the correct attenuation (0R47, 1R, 1R47). If you want you can then buy the correct value non inductive resitors (Not that I think you'd hear the difference in this application).
Played a series of sinusoidal test tones from 100hz through to 10Khz through the speakers.From whats audible to my ears,there really isnt any increase in overall volume of the tweeter compared to the sine waves played by the mid-woofer.
Hmm.....i am guessing the problem lies somewhere above 10Khz.
Anyways,does anyone have an idiots guide to making inductors ? Or if theres a shop that makes them;what do i tell the guy ?
Hmm.....i am guessing the problem lies somewhere above 10Khz.
Anyways,does anyone have an idiots guide to making inductors ? Or if theres a shop that makes them;what do i tell the guy ?
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