active crossovers : off the shelf & DSP views/experiences

[jacklelad]

What do people think of off the shelf active crossovers such as those from Behringer and Rane (in a bi/tri amping setup) as a means to avoid the complexity of designing/implementing one ?

Also, I read in an article that crossover designs don't just determine the frequency of the crossovers but are also designed to correct for other aspects of the drivers such as resonance ; is this true ? And if so, presumably the Rane and Behringer units are of no relevance in a hi-fi context ?

Views and experiences ?

[taloyd]

hello,

Behringer make cheap products with minimum-cost parts but have a decent engineering team, and so the products (especially in the digital realm, ie: DCX2496, DEQ2496) sound VERY good IF and only if fed a digital signal.

Rane make top-quality crossovers using the best components. I have a Rane AC23B and it's a fantastic unit. Build quality is impeccable, the layout is beautiful, the specifications are fantastic and the sound is transparent. It also has a delay on all non-tweeter channels, which is awesome as you can compensate for different acoustic centers. Rane is also a great company to work with, their "Tech Notes" on their website are very well written, informative, and useful.

Behringer also make decent equipment, but they're built to a completely different price-point, and they steal the majority of their designs from other companies like Mackie, Alesis, etc. They've been sued for this, and have lost several times in the past. Nonetheless the DCX2496 is an incredible product, you just need a 6-channel volume control. Pansonic digital receivers are very good for this, as they have a discrete 6-channel input, and have fantastic amplifiers. For $250 each for the DCX2496 and the Panasonic XR50, you can have a actively tri-amplified system with all the bells and whistles, with EQ for each channel, etc...

cheers,

-tal

[thylantyr]

Behringer make cheap products with minimum-cost parts but have a decent engineering team, and so the products (especially in the digital realm, ie: DCX2496, DEQ2496) sound VERY good IF and only if fed a digital signal.

I'm using the DCX with analog inputs and the sound is great.

Rane make top-quality crossovers using the best components.

I can show you schematics where they use 'cheap parts' too.

Lets look at this in detail. The DCX uses 4580 opamps.
The Rane AC24 uses ............. 4580 opamps. /// rofl ///
Rane also uses the archaic TL072 opamp in some designs...

Nonetheless the DCX2496 is an incredible product

yes it is.

you just need a 6-channel volume control.

no you don't, use analog input

[RobWells]

I use the DEQ and the DCX with my lexicon dc-2 processor. Have used with all scanspeak 3-ways and also with 'pro' type 3 ways aswell.

No complaints here for sound quality.


Rob.

[Paul W]

Most "fixed" crossovers -like the analog Behringers- don't provide a good way to compensate for driver flaws (and real-world drivers have flaws). So, you would likely need to add passive components to bridge the gaps between real-world drivers and textbook crossovers...a good active analog/passive hybrid can be as much work as a well designed passive crossover.

On the other hand, DSP based crossovers -like the DCX2496- can EQ individual driver response, delay, phase, as well as several other very useful functions...highly recommended.

"Wings" WTW project

[sam9]

I can'y say about their XO but I use the Behringer Ultra-Curve Pro for room EQ and am impressed by the results. Getting it set up right is an adventure just because it has so many capabilities beyond what I actually need. I opened it up some time back to upgrade the firmware and couldn't see any grounds to fault the manufacturing quality. Sometimes I think the "build quality" issue confuses expense and flash for substance.

I recall somone writing about B. Carver that only he could find a way to substitute cheap components and improve reliability at the same time. This was not meant as a compliment which struck me a peculiar thinking.

[wigginjs]

Thylander and RobWells:

Do you use RCA adapters for your inputs and outputs or do you actually used the balanced XLR inputs and outputs? Please give details about how you use your DCX's and what kind of systems you have. I'm in the process of testing an active 3-way with the Behringer CX3400 and am seriously considering the DCX.


RobWells:
What benefits does the DEQ add in conjunction with the DCX? Doesn't the DCX already have EQ functions?

[LineSource]

For analog crossovers I have not been able to get a good sound without using custom RC combinations between the buffer stages. No combination of the standard slopes could build the required transfer function. If you have read linkwitzlab.com notes on active crossovers you understand how powerful active crossovers can be.

I have a Krell Xover that supports plug-in modules, and a DIY Xover with Borbley JFET buffers. The JFET articles on the Borbley website are excellent.

Longer term I keep watching for a complete digital solution..digital from the DVD/CD, through a digital cable or fiber to the speaker, to a digital Xover with room equalization driving the bit stream to digital amps.

[thylantyr]

Originally posted by m0tion
Thylander and RobWells:

Do you use RCA adapters for your inputs and outputs or do you actually used the balanced XLR inputs and outputs? Please give details about how you use your DCX's and what kind of systems you have. I'm in the process of testing an active 3-way with the Behringer CX3400 and am seriously considering the DCX.


RobWells:
What benefits does the DEQ add in conjunction with the DCX? Doesn't the DCX already have EQ functions?

My sound system is never permanent, actually it's setup more as
a development tool. I'ts a simple setup.

DVD player -> Preamp -> DCX2496 -> Amps -> Line array

The DVD and preamp is RCA output. One of my amplifiers is
RCA input, the others are XLR input.

I made my own RCA to XLR cables, but you can buy them too.
For XLR to RCA on the Behringer output, I made a special cable to reduce
the gain 6dB to reduce hiss. This was suggested on the Behringer
thread, it works good when mating to a home amplifier using RCA
input.

[RobWells]

Pretty similar here. Use the lexicon dc-2 into the DEQ, then to dcx, then to amps. My power amps have gain controls which helps.

The deq accepts 'home level' signals as well as pro level signals whereas the dcx only works at pro (I believe - its been a long time since I've been round the back of my rack. )

I made all my own leads aswell.

The deq is not really needed here as I'm only using 1 band of parametric eq at the moment. Could easily do without it at the moment. (the dcx has enough processing to do this)

Maybe when I do my 2-way subs the deq will become more important - I use a feedback destroyer on my subs at the moment but am intending to get rid of it in favour of the deq.

If I was digital only, and stereo only I'd be looking at a used meridian 518 as a preamp. Unfortunately I have a lot of vinyl..

http://www.stereophile.com/digitalso...67/index3.html

Cheers,

Rob