Inductors

[Peter Empson]

Hi,
I'm just wondering what type of inductors other horn users are running in their crossovers? The ones I've been listening through are quite massive air cored designs from Falcon Acousitcs, which I specified to keep the DCR as low as reasonably possible.

However I wonder if this was the wisest thing to do, as the wire used is over three times thicker than my preferred (very thin silver) speaker wire!

I'm only using one or two watts max so I certainly don't need the power handling of such a big design either...

Playing devils advocate for a moment I can't help wondering whether a ferrite cored inductor might work well, as there would be no risk of saturation of the core at these levels, whilst still keeping DCR low and also the wire gauge thin.
But I can't get past the notion that it is a rather lo-fi solution!

Also, anyone using foil inductors? I've read mixed reports and given their cost I don't really want to gamble too much.

Any thoughts would be gratefully appreciated.
Best regards,
Peter.

<font color="#a62a2a" size="1">[ March 12, 2004 05:11 PM: Message edited by: Peter Empson ]</font>

[valvola]

Hello Peter

I'm talking about my experience on 12db/Oct. filter.If you don't use a horn-loaded bass section you'll need a 10/15dB cut on the efficiency of the mid-high section, then the DCR of the high-pass inductor will probably be less important in front of other qualities - so foil or litz or wathever else may be useful. The bass section (reflex?) will need the lesser DCR so if you can you may use a 3mm dia. wire (I've seen photos of 30Kg Japanese crossovers). If you have a horn loaded bass the efficiency and damping problems will be different and the DCR probably not a major problem. But did you ever thought about bi-amping? A cap before the high amp, plus another before the driver, will make the high-pass. But you will be able to use specialized amps for the two section, it will be easier to set the filters and the relative levels too. The whole set, by my experience, will be cleaner and more dynamic.
Bst regards.
Valvola

[Datubie]

I agree with Valvola. I've had my current configuration system for over 2 years now & I could never get the crossovers to work well with a single amp per channel. The need to attenuate the mid horn by roughly 10db seemed to squash the dynamics. I now use 2 amps per channel, one for frequencies 400hz & below and another for everything above. Even though I'm still using passive crossovers, the sound is pretty good. As far as I'm concerned, multi amping + electronic crossovers before the amps is the way to go. [img]graemlins/thumbs_up.gif[/img]

<font color="#a62a2a" size="1">[ March 19, 2004 09:15 AM: Message edited by: Datubie ]</font>

[Romy the Cat]

Peter, anywhere, under no circumstances use those flat foil inductors. The sound as horrible and it theoretically possible, even if you use the in the second order shunt applications. For bass? low pass filters go with air core as large as you can do. 6-8 ga. will go? if you can wind those types of the coils? The larger the better? even if you end up with two barrels of cupper in your room. Of course there is always an options to go multi-amping that will be always more interesting if it done properly (rarely happens)? I really do not see any other places when coil might be used? Ah, yes, there is a way to ?fix? some idiosyncrasies of S2 by a very mild coil but I would not saddest to do it. There are other ways to work around that problem?

Rgs,
Romy the Cat

[Peter Empson]

Hi,
Thanks for all the replies - sorry I've been a long time responding.

I currently run with 6dB attenuation on the mids to match them to the bass horns, so its not so bad to stick with one amp running full range for the time being - I don't have the space or the money to run multiple amps yet anyway, and my aim is to get the best integration between drivers possible (difficult at the best of times when using 3 way horns in the nearfield!).
However it is an option i'll try when I have the opportunity.

It seems my current inductors are probably ok for for the time being (but they're not quite up to your scale Romy!), so I'll leave them be for a while.

I've got quite a few more experiments to do with the crossovers to keep me occupied anyway. Just recently I went back to single wired operation and the improvements were dramatic. As were the benefits of finally going for (almost) complete silver/cotton wiring throughout.
These speakers are so revealing they really make every change you make easy to hear.

In the future I intend to experiment with putting more space between the components and will probably build some nice boxes for them instead of the board they're currently mounted on.

I also must get round to trying some more different grade caps and resistors as until now I've just used parts I was familiar with from previous projects.

The trouble is the speakers sound so good at the moment I feal loathed to change anything and am quite content just to listen whenever I get the time!

Best regards,
Peter.