[mjosef]

I have been using one since the mid 80's, Marchand XM1 (DIY), when I had the original Warfedale Diamond bookshelf crossing over to a VMPS Original sub @ 70Hz.
Currently I still use the Marchand (new XM1 board) in my bi-amped system crossing over @ 250Hz to VMPS RM1 midrange panels.
I tried a couple pro XO, Rane and ART Audio, both had a notable negative footprint on the overall sound. The Marchand with upgraded opamps has worked best for my purposes, with the added benefit of affordability(ie. cheap).

[JohnR]

I sometimes get the impression that folks are just waking up to active crossover systems.  You know, they've been around for many decades. 

Yes, but I think the technology has advanced enough now that "anyone" can have a go at it, quite inexpensively. By that I include not just the high/lowpass filters but EQ as well as measuring gear.

Mostly, active crossovers seem to imply some level of "DIY." That's appropriate, since this is the Lab. From that perspective, I think it's helpful to consider the sum realized in terms of not just sonic results but cost, ability to experiment and learn, and "recyclabilty" - who here never recycles a project? Speaking for myself, I get (frankly) pretty tired of absolutist positions on this-is-better-than-that.

In the non-DIY realm, there are systems like the Kyron Gaia, which I'm proud to say is an Australian product. It's not cheap, and it's not going to lend itself to amp-swapping. Perhaps this is (in terms of electronic configuration) the way that active systems might finally make some inroads into the high end market. Link: http://www.kyronaudio.com.au/Gaia.html

[Poultrygeist]

I am considering the Swiss Army knife DCX2496 to replace an analog active but this blog warns of issues when used with a tube preamp. Comments?

http://redspade-audio.blogspot.com/2010/12/first-test-keith-ws-tubehorn-system.html

[JohnR]

Yes, it's true, a DSP crossover has a "hard limit" that needs to be taken into account.

[Davey]

I am considering the Swiss Army knife DCX2496 to replace an analog active but this blog warns of issues when used with a tube preamp. Comments?

http://redspade-audio.blogspot.com/2010/12/first-test-keith-ws-tubehorn-system.html

It's not clear from their limited blurb what the compatibility issues were when operated with tube preamps.  They "seemed to clip?"  Who knows what the problem was, or even how they were operating it/them.    Most likely they didn't understand how to operate the DSP units.

The DCX2496 is designed for "professional" signal levels and its outputs will not clip below approximately 9.0 VRMS....when configured for unbalanced output.  That should easily be enough to drive a typical power amplifier to its rated output.

There is the question of whether the volume control is located upstream or downstream of the DSP unit.  Downstream is the much preferred location, but this obviously requires a multi (probably six) channel volume control.

I've had my DCX2496 for nearly ten years now, and find it's programming scheme and Windows GUI program the most logical and well thought out of any of the DSP units I've used.  There are a variety of modifications available for it also.

Cheers,

Dave.

[Davey]

Yes, but I think the technology has advanced enough now that "anyone" can have a go at it, quite inexpensively. By that I include not just the high/lowpass filters but EQ as well as measuring gear.

John,

The technology has been around for quite a while to implement (inexpensively) filters and EQ in the line-level domain.  However, I'm assuming you're referring to the multitude of DSP-based units that are available to folks now.  In that sense, I suppose you're correct.  They can allow just about anyone to become a speaker system "design engineer." 

If you haven't already seen this article, it's a good read, and outlines what type of technology could be implemented a 'few' years ago. 

http://www.linkwitzlab.com/Removed%20pages/x-sb80-3wy.htm

Cheers,

Dave.

[Freo-1]

Davey, excellent article, thanks for that.
 
Thanks to all for posting observations and providing feedback.  This is one area that my knowledge is not as good as I would like, so this has been an informative thread.

John R, your observations were spot on.  Your feedback got me back on track as to what I was trying to achieve.

[ehoove]

This is true, and i've found this capability very useful. Both units i have had are not very good sounding, the analog section really needs to be replaced to make these sutable for hifi use.

dave

Really? Mine is dead quiet, and sounds very good. I have considered sending it off to have the outputs altered and may do it in the future running the Maggies using the passive crossover route while the unit is being altered. I have been sufficiently satisfied that I have put this off for the time being though.
Regards,
Jim

[ehoove]

I am considering the Swiss Army knife DCX2496 to replace an analog active but this blog warns of issues when used with a tube preamp. Comments?

http://redspade-audio.blogspot.com/2010/12/first-test-keith-ws-tubehorn-system.html

I have been driving a DCX2496 with a Audio Research LS15 tube Preamp for over a year with no issues what so ever. FWIW
Regards,
Jim

[planet10]

Really? Mine is dead quiet, and sounds very good. I have considered sending it off to have the outputs altered and may do it in the future running the Maggies using the passive crossover route while the unit is being altered. I have been sufficiently satisfied that I have put this off for the time being though.

Mine is only used with a mic to to do a 1st pass at getting XO topology. It will get another chance after all the analog sections are stripped out and replaced with transformers.

dave

[Davey]

Dave,

I've recently completed a transformation of my DCX2496 using some Cinemag transformers.  It feeds into my MSB MVC and works really well.  I have no need for the analog inputs so didn't replace those.

I'd been waiting years for my DCX to develop some type of problem so I'd have the justification to perform surgery.....but it never did.    So, I went ahead anyway.

Dave.

[planet10]

Davey,

I have a full set of O'Netics transformers.

What differences did you note after replacement?

dave

[JohnR]

If you haven't already seen this article, it's a good read, and outlines what type of technology could be implemented a 'few' years ago. 

http://www.linkwitzlab.com/Removed%20pages/x-sb80-3wy.htm

I didn't mean to say that (inexpensive) DSP crossovers enable anything that could not be done with analog circuits. Other than pure delay... It's more about the barrier to entry.

[Davey]

Davey,

I have a full set of O'Netics transformers.

What differences did you note after replacement?

dave

Nice, smooth sound.

A shunting resistor is needed on the secondary to optimize/flatten the response into the desired load.
I used a 15k resistor for these Cinemag transformers which resulted in about 2.5db reduction but still yields about 1.5VRMS for 0dbFS signal levels.
The output resistance is now approximately 4.2k ohms, so driving long cables is not possible.  My cables between DCX and MSB are only one foot long.

Cheers,

Dave.