Series crossover question

[Peter Daniel]

I found this schematic and was thinking about using it for my Grand Slamm clones. However, I'm using two C-79 (insted of one), tweeter stays the same and no woofer (but still high-pass on a midrange). What kind of changes I would have to make to this design to be able to use it with my setup?

[Bricolo]

I'd say: supress C2-5 and L2
and you'll have to re calculate the L pad, with values for 2 C-79, and also another attenuation since you'll have +3dB with 2 mids

[Bricolo]

I think I misunderstood

You want to make them 2.5 way, aren't you?
So, yes, it would work

simply replace the woofer with the second c-79
if the C-79 are more efficient than the tweeter, you'll also have to place an L pad on the lower C-79

I'm not sure about the L and C values, but I think you could keep the same. But to be sure, you'd better wait for a specialist's advice

[Peter Daniel]

I think I want it two way, where midranges are in parallell. My main concern is L2, because I'm not sure if it's in midrange or woofer circuit.

[Bricolo]

L2 is on the midrange

the midrange has C1 and L2 around it-> a high pass and a low pass
the woofer has C1 and C2-5: two low pass

if you put out L2 and C2-5, and change the L pad's value, you'll have a 2 way system, with the 2 C-79 producing the same frequency range as the C-79+C-92 did


but by doing this, you change the XO orders (you'll have a 1st order low pass, instead of a 1st order bandpass+2nd order low pass)

if I were you, I'll simply replace the C-92 with a C-79, and change the L pad
maybe even supressing the L pad, since the C-92 is the only that has'nt one I think it's the less efficient driver. If the tweeter and the midbass have the same efficiency, don't keep the L pad nor the resistor on the tweeter

[uli]

Originally posted by Peter Daniel
I found this schematic and was thinking about using it for my Grand Slamm clones.

Hi Peter,

Look here: Seies

I built a MAXX Clone with a Xover very similar to the "Proteus"
works fine

Uli

[planet10]

Peter,

if you ignore the resistors (which are there to pad the various drivers), what you have is 2 2-way series X-overs that are ganged. If you remove the woofer, you also need to remove L2 and C2. You will not get any high pass on the midrange with a series XO (you will have to put it in front of the amp).

I suggest you go to Andy Graddon's site where he has a stash of info on series XOs. There is also a SS there for calculating values...

Everything depends on everything else in a series XO, and you will want to toss the L-Pad on the mids which will throw off the padding on the tweeter. That will change the effective tweeter impedance.... you might as well start from scratch

On the positive side -- if that XO works -- it means that you should be able to come up with a series XO for your config -- probably just a single L, C and maybe an R for the tweeter -- how close are the sensitivities of the T and a pr of the mids?

dave

[Peter Daniel]

Thanks Dave,

That's the answer I was looking foras this makes sense. I don't remember exactly the sensitivities of the drivers, but checking the current versions it looks like mids might be 1dB less efficient than tweeter. I think I saw Andy Graddon's site before, but lost the link. The one I just found using search is not working.

[planet10]

Andy just recently moved his site... he did post a link here. probably his most recent post... yep

Due to popular request.......
diyAudio Forums - Due to popular request.......

he hasn't got it all put together, but i sucked most of it before he moved it -- just in case... so if need be i could mail bits to you.

dave

[planet10]

Originally posted by Peter Daniel
looks like mids might be 1dB less efficient than tweeter

Then you will probably just need a small series R in the tweeter circuit, plus the L & C.

dave