Electronic Crossover

[Ian Mackenzie]

Some progress here,

If some of you don't need and all bells all tit bits active crossover but more a simple very hight quality 2 way box with provision for 12/18 db slopes or JBL monitor xover options options here is an idea.

I have been looking at a very simple but high quality buffer stages using Dual JFets in a differential / source follower design offering very low noise and distortion with low impediance drive capacility.

The simplicity is such it could be arranged on vero board with provison for fitting the RC values for the filters.

Over the Xmas break I will try and breadboard the design and test it and report on the subjective performance.

I will then consider offering the unit in the form of a black box to interested forum members.

Ian

[Robh3606]

Hmm

Sounds like an interesting idea. I wouldn't mind the option to change slopes. I like my M552/553 24db L/R crossovers but I would be interested to see what all the hubbub is about 12db vs. 18db vs. 24db slopes. It would be nice to experiment to see if I could hear a difference, when they were properly set-up, and if I had a preference. So far my experience with actives has been the ones I have so it's limited.

Rob

[Earl K]

Hi Ian

Well, you know I'm interested.

If some of you don't need and all bells all tit bits active crossover

What do you plan to exclude and include ?

<>EarlK

[Ian Mackenzie]

I have not thought about it that much.

The idea was a drop in replacement of the 5534/35 that you would throw in the trash can after auditioning the black box.

Least is best here for purity, balanced/unbalanced in out, and option of Eq VLF boost.

This would not be a Pa DBX drive rack, quite the opposite.

Unfortunately the suppy voltage is much higher that the existing 5535 or I would have considered a drop in module.

Ian

[Earl K]

Hi Ian

I think the overall "feature" set of the 5234/5 series would be fine.

ie; stereo,12 or 18db crossover frequencies determined by plugin cards on molex style pins, variable attenuation ( voltage drive ) on the HF outputs for balancing horns to woofers. Connectors ? How about EuroBlocks on the back ? There's nothing wrong with using tinned wire ends scrunched under pressure-plate fittings.

<> Earl K

[Ian Mackenzie]

Earl,

Thanks for the feedback.

The plug on boards is a good one.

Its very early days for this yet but I will be looking at ease of design and implementation and quality parts, particularly the passive filter elements.

Let me mull over it for a week or two

Ian

[Mannermusic]

A little noise from an old trumpet player: Have a relatively big JBL system: LE15A, 375/HL89, 077 (in vintage lingo). Have used a Luxman 2003 tube crossover low these past 25 years: 12 and 6 db slopes, +/- 5/8 octave crossover point adjustability or manually change tiny PF caps via soldering iron for more serious variation. Anybody using this antique? Sounds good to these musician/engineering technicians ears; smooth, musical with crossovers at 900Hz and 9000Hz. Kenton lives! What happened to these units - don't see them around? How does performance compare to the newer stuff covered in the crossover forum?

[JBL 4645]

Hey, David...

On the first bit, the 5234A's on eBay are quite inexpensive for what they do. Getting cards configured for what you need might be easier than you think, with some of the wisdom here on the Forum.

On the second bit, has been the result of my tiresome experiments and experience. Digital is still audible - it simply ain't ready, IMUHO.

Digital aint ready yet! Analog crossovers, good ones, are still king in my book!

Another thing I have to say is that I prefer 12db and 18db butterworth filters over all others! 18db filters yeild a warmish sound, yet still allows a bit of overlap which I like!

Whichever of the aforementioned devices you decide to go with, Dave, you can get outstanding results used properly!

I can hear the sound politics within each comment and since this was 2003 and I didn’t come onboard till 2005 and didn’t buy my first digital crossover till was it 2007? or 2008? Time passes by.

I usual go for a bit of -24db Bessel and L-R.

I assume it’s safe to say digital is now ready, now that 8 years have passed.

I have an analogue crossover but I’d dare use it for the HF I think its crossed-off at 500Hz. I could use it for bass/mid. So what do I do? Turn up the level until I hear some kind of disconcerting noise between the analogue and digital crossover?