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I'm a bit confused about EV's vintage X8 Crossover.
http://mypicsonline.net/archive/archives.telex.com/archives/EV/Miscellaneous%20Electronics/EDS/X8%20%26%20X36%20EDS.pdf
I have some EV SP15A's in the mail now and was looking for an easy crossover for them. Eventually want to cross them over around 675Hz to some DH1's I have. But was looking for an easy make do crossover just to get started so was looking at EV's X8 as they are not that hard to get a hold of.
Not that great in crossovers for sure, and cannot figure out as per the diagram schematic in the link above, as it shows a 1.5 (maybe 1.6)mh coil and a 26mf cap crossing over both 8ohm tweeter and 8 ohm woofer at 800hz.
What am I missing? (That's more like 4 ohm crossover at 800hz).
Follow Ups:
I have a program that models crossovers.
It is a Linkwitz-Riley crossover.
Like Pesto says Q is .5 for a slow crossover.
Actually a lower output at crossover
when compared to Butterworth filters.
For more info see link.
DanL
I have quite a few caps and coils laying around. So I'm going to try 3.5mh with some 13.6 or .7 caps and then play around with the caps a bit after that. I read somewhere that the EV X8 is in cased in tar so imo not worth trying out.
Thanks for the input!
BTW my EV SP15A's might be here on Saturday. The Baltic birch will be here tomorrow. :)
Time to make some sawdust.
I started with speakers then went the tube route.
I remember that sawdust smell well.
Boxes damped with sand and cross braces.
As well as foam and deflex panels.
Port flared at both ends.
Dynaudio D260 Tweeter
Audax Aerogel Midranges
HiVi D10G Paper/Kevlar/CarbonFiber w Neo magnet
Only one cap per channel
Woofer has seperate mosfet plate amp on each
danL
It's all about "Q". Filter shape.
The 2nd order Linkwitz Riley "textbook" filter (Q = 0.5) for 8ohms @ 800 Hz Gives 13 uF for both caps and 3.2 mH for both inductors. This crossover has a theoretical sum at Fc of 0db.
The values they have used there, 26 uF and 1.6 mH are for a 2nd ordeer variable Q "textbook" filter with a Q of 1.0. This crossover has a theoretical sum at Fc of 6db.
(Notice when we went from a Q = 0.5 to a Q = 1.0 crossover the cap size doubled and the inductor size halved.)
The reason I parenthesize "textbook" is because these filters are directly from calculators and there is no compensation for any frequency or impedance variations.
Cheers,
Presto
Thanks for the response, Presto.
Does this mean that the X8 would be Louder at the crossover point as compared to a Q factor of 0.5? (Assuming textbook scenario)
[If that's true, no need on even trying it.]
The 2nd order q=1.0 crossover, with ideal drivers, will sum to +6db bump at the crossover point. The drivers involved have their own response which needs to be factored in.
I would not go out of my way for a filter like this, unless I was specifically looking for a X8 to match up with specific EV components, or if it had collectors value.
I'd like to know what they were up to there...
Cheers,
Presto
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