Hello,

I have dual HSU subs , a VTF-2Mk2 and a VTF1. I use my old Counteroint Hybrid Amp and a tube preamp for music and I use an Anthem Amp and Outlaw preamp for HT.

I went to visit someone who has twin VTF2-Mk3 subs with a professional type Rane active crossover.

The crossover really makes the bass tight and defined. I use single ended IC's with Bullet plugs so I can't use the pro crossovers with XLR connections.

Can somneone recommend a good active crossover that I can use with both subs, a an anit-resonance filter and the ability to adjust what goes to my mains?

Don't the subs have built-in crossovers? If they did, I'd use them.

I'd also recommend running them in true stereo. A way to do this is here .

Yes, the two have built in crossovers yet when you use a great active crossover, the SQ is much betetr.

That's totally untrue. It depends on the particular circuit used in the crossover. The ones in your sub are probably just fine.

A particular active crossover cannot have nearly the impact on the sound quality as you seem to think it can. The fact that the system as a whole is actively bi-amped has far, far more impact on the ultimate sound quality than the "quality" of the active crossover unit it's self.

I know a guy with twin HSU subs and he uses a RANE pro active crossover. The Bass is so deep, tight and controlled.

He now is using two ampos and says the Rane allows him to get great everything!

Whatever. I think if you did a dispassionate accessment of what was contributing to the "deep and tight" bass, it would be because of other factors than his use of the RANE crossover.

"Great everything" comes from getting a lot of details right, from placement of the speakers to acoustics of the listening room, and least significantly, the particular electronics employed.

The only time electronics will make an obvious impact on the end sound quality is when a completely different topology is being employed, i.e. using tube based gear instead of transistor based gear. Even then, the changes are not going to be "like night and day". The acoustics of the room play a much more important role in the sound of a system than any electronic change that can be made.

I am thinking a getting a Behringer Cx3400 Active crossover .

Soundhound: Relax. Take a deep breath. Don't bite Liz's head off.

Liz: In the Pro Audio World, Behringer is like the knock-off handbags you find on the streets of NYC. They may look Ok and work OK for awhile, but in the end, you get what you pay for. Your friend's gear that is made by Rane is of a much higher quality than anything Behringer makes.

In all of the messages in this thread, I'm still not exactly sure what you're trying to accomplish by adding an external active crossover. Where in your system would it go?

Well, it could have been worse - he could have opted for the digital version which would involve an unnecessary A/D and D/A cycle!

Actually, I don't have a lot of respect for either Rane or Behringer. I've made my own, using components that neither one of them would be able to afford to use in a commercial product. Things like polystryene capacitors, video buffers instead of the usual audio op-amps for the bandwidth they afford, etc.

I am thinking of getting a Rane unless you want to make me a Crossver Altec? Please let me know?

The Rane will go between the Tube preamp and Tube amnp as I keep music and HT close by apart.

I'm using the dbx brand between my tube pre and power amps. They seem fine.

Generally, any crossover made for pro applications is not going to be up to the standards of the rest of your system. Rane, Samson, Behringer etc are all made for PA and other such uses, not audiophile grade. Cheap capacitors are the main culprit, followed by the overly-complex-for-what-you-need state variable filter implementation.

Check this link out - they make what you need.

Marchand Electronics

Marchand are way too costly!

Well, what can I say?!?!?!!!

If you've taken the time and money to invest in tube gear and upgrades, what sense does it make to place some dog-crap piece of gear in the signal chain which is going to mess up the otherwise good sound?

I don't understand the logic, but then again, I have a simple mind.......

Can you build me an active crossover?

Sure, but it would cost you about 3 times the cost of the Marchand ones I posted a link to.

My time isn't cheap.

This is confusing to me. According to reviews posted online, both your preamp and your amplifier cost over $2000. Yet, the most you want to spend on a crossover seems to be $500. Placing the crossover in the system will affect the sound of the system almost, if not, more than changing out the preamp or the amplifier. Think about it. You're asking the crossover to take in the signal, split the signal, and then output the signal to its destination. For the care and expense you've taken to put together the rest of your components, it seems odd not to take the same kind of care here. Just my .02 cents...

The Marchand Electronics crossovers that Altec recommended seem to fit the rest of your system perfectly with regards to budget and the level of everything else. There's always used.

If you haven't done electronics building before, an active crossover is probably not the best place to start, but ... if you don't get frustrated easily, if you can read, understand and follow directions, if you can carefully observe what you're doing, you might be able to go the 'kit' route - eventually.

If you're not experienced but tempted to try, I'd pick a couple other projects of a simple and less expensive nature to build first - see what you can learn, test your own abilities. They don't even have to be audio projects. (I'm talking about assembly here, not about circuit design.) I'm comfortable with such a project, but then I started watching my dad build Heathkit electronics and started with some simple projects a few decades ago.

If you're not going to venture into such a project, don't lament the cost of a Marchand or similar unit too much. When an electronics hobbiest is buying a limited number of high-quality parts, the hobbiest is paying more for the parts in the first place than a business that may use thousands of the same part. The Marchand units have a proven track record and carry a warranty.

I picked up a Behringer unit, used, for about half price to experiment with, not to use long term. If the concept works well with my speakers, showing an advantage over the standard passive crossovers, then I'll take the time and effort to make, or spend the money to buy, active crossovers on par with the rest of the gear. I'm not relying on my ears alone either. I bought a pair of test microphones and plan some 'before and after' measuring and analysis. After all, sounding different isn't automatically better, and very small differences don't always deserve the budget needed to go 'active' on the front three or all around.

EDIT: Pardon me, but I just re-read the initial post in this thread ...

If you're looking for an crossover for the subs/mains split only, via an external unit, you might find a used Outlaw ICBM. The ICBM can handle stereo subs too, but is a maximum of a 6.1 unit. For 7.1, the rear surrounds are run mono via the ICBM.

There are also used SMS-1 units if you're looking to 'tune' a sub's response to a particular environment. And don't forget room treatment(s) if they'll fit your environment - if the room is causing a major problem, it's often better to fix the room rather than relying on EQ alone.

Chances are very high that, the first time you listen to your newly actively-crossed over system, it will sound worse, or VERY worse than it did with the stock passive crossovers.

Thia is because of the fact that not only is all "voicing" which the manufacturer labored long and hard for is now gone, but also the balances between the drivers is all out of whack.

You are now at square one. You are in the driver's seat. You are now at the place where the manufacturer was before he got down to designing a crossover for his speaker.

The active setup most certainly has the potential to sound significantly better than the passive one, but it is NOT plug-'n-play!!!!!

Patience, and the ability to "listen through" the sound you are getting, to the sound you want, is everything.

It could be that this thread is meant for mains/sub(s) crossover rather than 'full-range' passive crossover replacement - the exchange is good anyway.

Altec: Chances are very high that, the first time you listen to your newly actively-crossed over system, it will sound worse, or VERY worse than it did with the stock passive crossovers. BB4TB: Yup.

Altec: This is because of the fact that not only is all "voicing" which the manufacturer labored long and hard for is now gone, but also the balances between the drivers is all out of whack. BB4TB: Yup - that's why having all kinds of 'adjustability' is a good idea, hence the Behringer unit to aid in determining what's needed before building a less flexible crossover of better components.

Altec: You are now at square one. You are in the driver's seat. You are now at the place where the manufacturer was before he got down to designing a crossover for his speaker. BB4TB: Nearly square one. I do have the manufacturer's frequency response graph and will have a limited set of my own acoustic measurements before and after. I can also make make a schematic and take electronic measurements of the original crossover in action to know about any attenuation beyond frequency division. If I don't like the results, I can always restore the original crossover.

Altec: The active setup most certainly has the potential to sound significantly better than the passive one, but it is NOT plug-'n-play!!!!! BB4TB: Yup.

Altec: Patience, and the ability to "listen through" the sound you are getting, to the sound you want, is everything. BB4TB: It is significant, and part of the enthusiast's experience to explore the possibilities, enjoying the process as much as any potential results.

Beyond a division of frequencies, do the crossovers you made contain any significant 'voicing' and, if so, did you work from a circuit already designed for the drivers you were using, work it out on your own or ???

Yup...

All the "voicing" was arrived at over considerable time by ear, and listening to many, many recordings. Even now however, I can easily adjust the HF to suit certain recordings.

The crossover it's self has no frequency response altering capability.

The output of the crossover which goes to the woofers is routed through an active 1/3rd octave equalizer which more than anything corrects for some weirdness in my room in the vicinity of 200Hz.

The crossover to the HF horn is at 500Hz (they're designed to operate down to this frequency) to allow the single horn to cover as much of the audio range as possible. Having a single diaphram and horn cover such a large range aids tremendously in creating a coherent wavefront.

In the crossover's HF output is placed a line level passive shunt L-C-R variable Q filter with two fixed frequencies which were chosen by experiment and listening. The amount of impact the EQ has can be varied by two potentiometers, one for each filter frequency, which varies the depth of the notch and the filter Q.

Now before somebody squauks about my use of a passive filter, I must point out that there is a world of difference between a line level passive filter like I'm using and a speaker level passive filter (crossover). Line level passive filters are noiseless and distortionless, which is why I went this route. The passive filter guarantees that no electronic degredation will take place in the equalization stage.

Speaker level passive filters (as in crossover networks) produce all kinds of distortions because the filter is it's self driving a reactive element (the speaker driver). Additionally, because of the high voltage and currents involved in a passive speaker level crossover, it is extremely, if not impossible, to find parts of the quality and precision that can be used at the much lower voltages and currents of a line level passive filter.

To address Lizards original question "Can somneone recommend a good active crossover that I can use with both subs, a an anit-resonance filter and the ability to adjust what goes to my mains?"

I use a similar one of these from NHT. I use the X1 version since I have their speakers but the X2 version is for non NHT subs. Lots of capabilities.
http://nhthifi.com/current/products/speakers/x2.html

Thanks, I must look at this since it uses RCA's


"To address Lizards original question "Can somneone recommend a good active crossover that I can use with both subs, a an anit-resonance filter and the ability to adjust what goes to my mains?"

I use a similar one of these from NHT. I use the X1 version since I have their speakers but the X2 version is for non NHT subs. Lots of capabilities.
http://nhthifi.com/current/products/speakers/x2.html"

Actually allows use of either RCA or XLR on both input and output.

The Counterpoint is no longer in the system. I now use a VAC Pa100/100 tube amp.