So let's make a crossover

[jbeckva]

Ok, figured these CV's are probably old enough to consider new crossovers. I took a look inside, and quite frankly I'm not impressed with what's in there, so what the heck - let's build some crossovers eh?

The original crossover points are 500hz and 3500hz. Now supposedly the two midranges may be "different", but in what exact way I'm not sure. I'll open it up and muster together a crude schematic in a bit, but I figured for now let's get the conversation started eh?

Specs...

FREQUENCY RESPONSE: 29 Hz –20 kHz
POWER HANDLING: 5/350 Watts RMS Min/Max
SENSITIVITY: 101 dB (1 Watt @ 1 Meter)
IMPEDANCE: 4 Ohms
LF DRIVER: 15†Die-cast Frame / 2†Voice-Coil (152WR)
MF DRIVER (upper): 6†Cone (M-6 or CM-6)
MF DRIVER (lower): 6†Cone (M6-H or CMR-H)
HF DRIVER: 1†Voice-Coil Horn Tweeter (CS-5)

(hmm.. 4 ohms.. eh??.. guess I'm going to verify that).

One chief concern (obviously) is the power handling. With either the PL or Crown, we're trolling for bear here. So this crossover had better be robust enough. It also would be nice to have things crystal clear.. no doubt.

Simple enough project? I'm open to input! I'll measure out the driver resistances and make a current schematic first, then we go from there...

 

[speakerman1]

Do you know what your inductors are? Anything in the x-over other than caps and inductors? I do have a meter to read inductance.

Larry

 

[jbeckva]

Do you know what your inductors are? Anything in the x-over other than caps and inductors? I do have a meter to read inductance.

Larry

I'll have to look inside. Yeah, they have a couple of l-pads, fuse, and circuit breaker too. It's one of those "stick on the back of a cheap plastic thing with heat glue" crossovers tho, so I was thinking of putting some effort into decently designed and laid out crossovers from scratch. Or should I keep the inductors?

Think I'll also replace the terminals with decent gold plated banana types too. Hmmm... put some "battery cable" (8 guage? heheh something "hefty") where lil 16 guage wire is now.

Some may say I'm on a lipstick on a pig mission... heheh... ya never know!

 

[speakerman1]

Are the inductors windings and magnets? You can go with a 12 ga. Air Core inductors. Danny said the Erse ones are better quality than the Goertz.You will want polypropylene caps. I ran 12 ga silver coated OFC wire. Yes I always built my x-overs point to point soldering and putting it on the bottom of the cabinet. Tell me what you want from PE and I'll see what my prices are.

Larry

 

[laatsch55]

Jer, the D-9 crossovers are crap. My 9's measure 4.9 ohms at the terminals. Have you googled"upgrading D-9 crossovers"??

 

[jbeckva]

Heeh... already one major problem. I can't make myself turn the music off so I can start opening the speaks up to figure out what I have! Sounding particularly purty right now. 88K, 24 bit SACD rip of Steely Dan (winks at Lee... you will come to the dark side, oh yea verily you will.... )

Probably have to haul back in the Infinity's, or I'll never go past talking about this project...

 

[jbeckva]

Jer, the D-9 crossovers are crap. My 9's measure 4.9 ohms at the terminals. Have you googled"upgrading D-9 crossovers"??

Well.. that's why I started this-here thread. Lets make a better mousetrap.. heheh.

(but alas... see above... now it's Dire Straits.... )

tomorrow.. I promise.. before I turn anything on... pics and skeezers and measurements.. all that..

 

[jbeckva]

Making 'er now (the skeezer). Got some weird goings-on with this one here... .

 

[jbeckva]

Ok, so here's the skeezer. I'd put values in it, but nothing marked on the inductors and the caps.. hard to say right now. We know the crossover points are 500 and 3500. Note how the two mids are in parallel and present 4 ohms to the circuit. 4 ohms on the woofer and 8 on the horn tweeter.

What's up with that part feeding the tweeter? I know I should recognize it, but .... what's it "think it's doing"??

[attachment=0:1b0m7304]cvskeez.jpg[/attachment:1b0m7304]

 

[laatsch55]

The Circuit breaker isn't shown.

 

[laatsch55]

That's a hi-pass filter.

 

[jbeckva]

I "simplified" heheh... it's actually between the positive and the 1st cap going to the tweeter

Neither are the two level controls...

 

[jbeckva]

That's a hi-pass filter.

Yah.. of the 3rd order butterworth kind (err.. I think that's what I see there comparing with some examples?)

 

[laatsch55]

N o values on the inductors??

 

[laatsch55]

alkeng.com He's the filter genius, you might even be able to understand some of what he is talking about, I don't. Lot of good info there Jer.