Please Suggest An Electronic Crossover

Speakers:  Infinity Kappa 9

Preamp:   Audio Research Reference 3

I’m looking to find an external crossover to add to my system.  Preferably a pre-owned unit…will consider new unit.

Would like to limit to $1k…but will go to 2k for the right unit.

What is your application?  Are you going to add a sub, or are you converting to an active speaker?
To expand 2 way or 3 way speakers.  

Single DAC or a DAC for each channel?
or use the DAC from the crossover?

Digital crossover convert analog to digital back to analog.
MiniDSP does have a multiple crossover board that has a built in dac or just outputs digital but would require a DAC for each crossover point

So is the External for the Kappa? You want to remove the  stock XO and add your own? Take care of the dip below 1 ohm? Amp killers..

First Watt B4 1500 new, 1000-1500.00 used

erik_squires …. I am looking to bypass the internal crossover in the Kappa 9 speakers.

 I am looking to improve on the existing internal crossover in the speaker.

Hey Mitch,

That's a good plan, but those crossovers are complicated.  They do more than simple low pass/high pass slopes but include impedance and frequency equalization.

You'll want a miniDSP for this. You'll also want to understand how the original crossovers worked though and I encourage you to learn to do a complete speaker analysis before attempting this. This isn't something you can do by ear so you'll need to have a measurement kit.

DIYaudio is a good place to go for help, far better than audiogon. If you go with Room EQ Wizard those forums are also going to be helpful.


Last bit of advice

A simple compromise, and one I encourage, is to start by making a hybrid.  Use a high level crossover to separate the bass from the rest of the drivers.

You'll need to bypasss the relevant high and low pass filter sections, but leaving the rest in place.


I would be looking a MiniDSP with Dirac live and running an amplifier on each channel.Passive XOs would take a lot more skill, and probably…. Unless you are really good… the outcome would likely be better with the EQ of the MiniDSP.
OP I’ve worked many Kappa 9.1, 9.0, 8.1, 8.0 crossovers. Easy fix. leave the mids and highs alone for just a bit.

Look at the schematic you will see the MB driver and the bass driver.

Remove and tape off the the wiring to both, BUT only those two.

A pocket set of 4 like below or GR has TUBE Post that are very inconspicuous. I don’t care what you use, you need two sets of post

You have a mid bass, and you have a bass driver, wire them in phase to the post with good copper, # 12 is even over kill but it is what I would use. Order the correct size crimp connectors or solder to the speaker
- and +.

Order a Behringer DCX 2494. 2-300.00 usd. It is not for mids and highs only bass.

  • Signals can be split in various ways to assure precise sound by using the optimal frequency range of each loudspeaker
  • 3 analog inputs (one suitable as a digital stereo AES/EBU input) and 6 analog outputs
  • Superb high-end AKM 24-bit/96kHz A/D/A converters
  • Dynamic range of 113dB
  • Easy connection of external digital signals with sampling rates from 32-96kHz is a breeze
  • Precise dynamic EQs for level-dependent equalization
  • Extremely musical parametric EQs selectable for all inputs and outputs
  • "Zero"-attack limiters on all output channels guarantee optimal signal and loudspeaker protection
  • 4 different mono and stereo output operating modes, all with individual crossover filter types (Butterworth, Bessel, and Linkwitz-Riley) with selectable roll-off characteristics from 6-48dB/octave
  • The delays for all inputs and outputs are adjustable
  • Future-proof Ultra-Drive Pro software enables single or multi remote control via PC

I couple this with with Behringer NU12000 (3-400.00 usd each) NU4-6000 ( it has 4 outputs but half the power) it may be a better option. Turn OFF it’s OB DSP
The 2496 can handle 2 more outputs for two more HUGE passive subs. 500 pounders aught to work :-)
Just add another NU12k. Each channel will drive 4-6 high excursion 12" drivers to over 120 db.. You don't have to be to picky they will drive a 1 ohm load for a while too.. (hook up the fans)

I keep 4 NU12000 on hand they are such a great amp for bass.
I disconnect two of the three fans and put the third on a micro toggle.
I’ve yet to have to turn it on... BLASTING at 100 db for hours..

SO for the cost of two amps or one with 4 outputs, a crossover, cabling to run everything 1350.00 and about 3 hours of work.

IT WILL BLOW your mind.. how easy it is to set up with the best bass you have EVER heard..

The bass drivers are NOW direct coupled, the dampening will actually work now. The only way to have amp dampening is to have ZERO in the way of the amp output and the speaker input, close to servo control.
I actually like it better to tell the truth..

I use # 10 SJOOW pro speaker cable with copper speak on connections, for the pro side hook up. SJOOW is 99.999 copper about 50-100.00 per 2 X run.

I have two more ways but it involves an onboard XO mod. It cost a lot less. It works well also. The Kappa 9.1+ addresses the less than one ohm problem. I think it dips to 3.6.

The rest of the XO is pretty darn good to tell the truth..

If you need any help just PM

Happy Happy
And you've fixed how many? I figured.. ZERO.. Like I SAID I have two more fixes that are a lot less expensive, the rest of the XO is fine.

The other requires one cap one inductor and one resistor.

You can even use the old bass speaker terminals.. to look authentic.

My way is better.. plain and simple.. So There!!! :-)
PS:  Please don't just pick crappy crossover settings and try to fix everything with global EQ. 
   So many recommendations on this subject. Crossovers, room correction, sub integration, and all others play into the equation. For a relatively cheap way to experiment try something like an Outlaw ICBM. Not in production anymore (originally $250 MSRP) but can be found in the used market.
   To get really specific and get something you can order to your specific needs try this place, A bit more money but very good quality.....
As the OP i asking for recommendations , I feel free to make one without being accused of generating “spam.”
I have had excellent luck with a vacuum tube electronic crossover custom built for my system by  Marchand Electronics.  I biamped my Magnepans, completely eliminating the factory crossovers.  Results have very satisfying.
If you mean an active crossover, no I cannot recommend one. I have not heard a single one that sounded good. A couple I tried to upgrade with boutique components; I could improve them, but never to a satisfactionary level

They are good enough for pro audio, but they are not good enough for hifi. I’m sure a genuine hifi quality unit could be manufactured, but that wouldn’t be cheap.


I just about listened to them all tube SS (analog) even a Deqx (digital domain, sterile is the word that come to mind).

The very best I found was the newer discrete SS Nelson Pass "First Watt B4" active analog xover only a few were made, they were $1500 but do come up used though. (some idiots ask a fortune though tell’m where to go)

Cheers George
Hello Mitch4T!  If you want it with fixed frequencies, use one of the units from miniDSP.  If you want to play around with the crossover points get a DBX unit (like the 223 - different kinds of connectors on different units) will let you have fun trying different crossover points. I have (and am using) 4 miniDSP and 3 DBXers. Great stuff!
Enjoy, Boomer Bill
+1 to eric_squires.  Bloody hell man!, 
Unless your vintage x-covers have electrolytic caps don't f* with them! Just pass enough juice to reform those old Mylars or what have you.  Replacement of resistors if they have gone out of spec could clean thing up a bit, but an attempt to re-engineer those x-covers will likely not end well. I've owned RS-1.5 and sadly parted ways, but still have some of my best audio memories those paired with an early ps audio preamp and a highly modified dh-220  built by an EE who worked for the sound lab in Groton CT. .
I have used the Parts Express DSP-408 with good results. Offers a big slice of what mini-DSP does for next to no money.  Experiment with that and see if you think you’re making progress. You’d have to break out the woofer input to direct couple it. I agree that leaving the rest of the speaker xover for now is a good phase 1 plan. I have also used HHHF as a resource and Tony is great to deal with. Have fun!
+1 jrpnde

I use a Marchand Electronic Crossover.  Amazing piece, built entirely to your spec.  Think seriously about bi-amping, purchase another amp.

But, at any rate, check out Marchand, it will give you an excellent idea of what is possible.

Well truthfully, those old Infinity crossovers sucked due to how they were optimized.  They were optimized for frequency but not impedance I suspect in large part due to the tools available at the time.  Very demanding for amplifiers but they don't need to be.

They don't need upgraded parts.  They usually need a complete re-think. I know this is anathema, but this is a case where a good modern crossover builder with better tools can come up, and they have, with much better circuits, but to do this you need to know how to analyze a speaker.  Most arm chair speaker hobbyists don't and it's a long learning curve. 

If the problem is in the bass, my suggestion to use a hybrid set up can resolve your issues without adding too many phase/impedance/slope matching problems which all crossovers ( line level or speaker level) have. 

Maybe look online to see if you can find a person selling new crossovers with better impedance characteristics is also a good option for the Infinities.
I am using a dbx venue 360 With a 12v linear power supply very transparent ordered a passive line level high pass crossover from Marchand electronics  as a experiment and use the dsp for only bass
 I have two Berringers (I upgraded to the DBX).  Both for sale and one was modded by Smiles Audio from the UK (losses 2 of the 6 inputs but off the charts improvement).  
Xilica brand and then probably look at either the xp 4080 or the more expensive xd 4080. The XD uses fir filters but you can probably get by with the xp. Unlike a lot of x-overs these actually have good musical tone and good chip power to handle using filters for notches etc as you do corrections. These are very popular with the klipsch crowd
If you’re going to do it, then I would suggest going to a FIR based DSP so you have the capability to also equalises phase.

That is where a significant amounts of the magic happens in passive speaker crossovers (opt not).

Or one can believe that spreaders which are not phase and time correct, are somehow still able to be referred to as having “high” fidelity. Built it is not true.