Replacing crossover inductors

[Strider]

After replacing the caps on the crossovers on my Proac Studio 140 I now want to upgrade the resistors and inductors, the resistors are easy to replace a like-for-like but go for a higher quality component.

The current inductors are ferrite cored and I'd like to replace them with air-cored. Removal/replacement is straightforward but I've got a question regarding resistance in the inductor, The coils on the crossover are:
0.5 mH @ .32 Ohm and 2.19 mH @ .52 Ohm. I understand a little that having a vey low resistance is better but how important is it to have the resistance near identical?
I'm looking at Jantzen air coils and resistors from Hi-fi Collective.
Thanks!


The picture n the left is the original crossover before I replaces the caps with Clarity Caps.

 

[karma67]

when i changed the inductors on my ns1000's i took the advice from others that had done it and went for the closest value to stock inductors.

 

[awkwardbydesign]

I always try to replicate the resistance as well as the inductance. Which means bigger and more expensive. Changing either will change the effect.

 

[Strider]

Thanks gents, I've found that the lower the resistance equates to a larger diameter copper winding, makes sense as the 'thicker' the wire the lower resistance.
comparison between core windings show that 18 AWG (1.2mm sq) gets me to the closest resistance other than increasing diameter = more cost!

 

[Strider]

Okey Dokey - total of £73 including VAT and postage, there's about a three week lead time on the inductors but I can wait..
Watch this space..

 

[tuga]

Did you measured the response before and after the replacement?
I would not trust the specs.
Might be worth measuring the acoustic response of the speakers using a prototype/clone of the crossover soldered onto a breadboard.

 

[Strider]

Did you measured the response before and after the replacement?
I would not trust the specs.
Might be worth measuring the acoustic response of the speakers using a prototype/clone of the crossover soldered onto a breadboard.

I did a rough measurement using my PA3 including RT60 and could see a large bass null at 80Hz -30 db but placement can ameliorate the null, moving the sofa back by 9" (roughly 1/5th) pushed around 11 db and although a bass hump at 160 Hz helped iron out the missing bass loss of 60/90/120 Hz. Moving the sofa is no small undertaking (it's a massive L unit of 50 mm MDF and is probably the best part of 120 Kg with all the cushions removed.
I've pulled the speakers to a rough 17" from the front wall for a quick reference but it's 23.30 and my back is killing but be assured I'll have a fiddle tomorrow, @tuga you're a man after my own heart and you've an encyclopedic knowledge for which I'm most grateful. Tomorrows another day and I'll continue. It don't sound half bad so far...
Churs mate.

 

[Fatmarley]

It looks like I'm too late now, but the larger 2.19mH may sound a bit better with a lower resistance coil (possibly tighter bass). I'd try and keep the 0.5mH as close as possible.
In an ideal world, you'd measure the individual drivers and model the existing crossover to see if it could be improved.

 

[Alvolake]

FWIW I also thought about changing my ferrite cored inductors for some Jantzen Air Foil cores and indeed I bought them. Still waiting for them to be fitted - need to make bigger boxes for my external Xovers -but in correspondence with Peter Comeau, the designer of my WD25TEx speakers, he told me not to expect miracles and that air cores are just bigger than ferrite cores and he doubts very much there will be any change in sound. Despite his background I do hope he´s wrong for once.

 

[Alex 54]

After replacing the caps on the crossovers on my Proac Studio 140 I now want to upgrade the resistors and inductors, the resistors are easy to replace a like-for-like but go for a higher quality component.

The current inductors are ferrite cored and I'd like to replace them with air-cored. Removal/replacement is straightforward but I've got a question regarding resistance in the inductor, The coils on the crossover are:
0.5 mH @ .32 Ohm and 2.19 mH @ .52 Ohm. I understand a little that having a vey low resistance is better but how important is it to have the resistance near identical?
I'm looking at Jantzen air coils and resistors from Hi-fi Collective.
Thanks!


The picture n the left is the original crossover before I replaces the caps with Clarity Caps.

I would be wary of changing inductors for a different type, even if the inductance is the same the resistance and "Q" will change which a good engineer will have taken into account in the crossover design. This could result in changes in the response which the ear could initially interpret as desirable.

 

[Strider]

I would be wary of changing inductors for a different type, even if the inductance is the same the resistance and "Q" will change which a good engineer will have taken account into account in the crossover design. This could result in changes in the response which the ear could initially interpret as desirable.

Thanks @Alex 54 I was wondering of the the same thing, the resistance is exactly the same as the originals but if the frequency response changes and depending how far across the band I can address that with a little tweaking. I'm confident that the replacements will be beneficial especially by at least moving the coils at right angles to reduce crosstalk.
If it all goes Pete Tong at lease I can reverse the changes.

 

[Strider]

The inductors and resistors finally arrived today and I've been having fun with the iron!
I've still got a little fettling to do with he final resting places of the inductors after I've made an initial test, once I'm happy I'll get busy with the hot melt glue gun.

I don't pretend to have any soldering skill apart from general AV stuff so laugh away at my butchering!

 

[lazycat]

The inductors and resistors finally arrived today and I've been having fun with the iron!
I've still got a little fettling to do with he final resting places of the inductors after I've made an initial test, once I'm happy I'll get busy with the hot melt glue gun.

I don't pretend to have any soldering skill apart from general AV stuff so laugh away at my butchering!

Sweet Lord those are big .

Pleased they finally turned up. Tho' you're a lazy bugger for not making your own...... bit of twin n earth and a broomstick.

 

[FirstWatt]

Sweet Lord those are big .

Pleased they finally turned up. Tho' you're a lazy bugger for not making your own...... bit of twin n earth and a broomstick.

Those Woofers are off the open market now Seas CA18RCY ,closest to it is the CA18RLY , if you get the urge to make your own
but ProAc will have their own stamped version