Electronic Crossovers ????

[mbottz]

Anyone have experience with Electronic crossovers? I wish to bi-amp or Tri-amp my L-300's. What would I look for? What brands are best? Any Suggestions would be greatly appreciated.

Thanks in Advance

MB

[Uncle Paul]

Are you building new networks or modifying the originals?

[mbottz]

I was under the impression that with an electronic crossover and a separate amp for each driver I would not use the existing crossovers. Can someone explain the setup for bi-amp and electronic crossover in simplistic terms. I am not real clear how it all goes together. :blink:

MB

[Robh3606]

Ok

Analog actives don't take into acount specific driver peaks, dips or tilts in driver response a good passive will. There are times that you can't analog active biamp without the custom driver or horn tailoring that is available in a good passive design. In that case you would use both the active crossover for the basic crossover point and a passive network to provide EQ to keep the driver/driver Horn combo flat over it's passband. With digital crossovers you have the advantage of almost infinitely adapable filters that can EQ the driver in it's passband and do the basic slopes all in one. The problem there is another A/D-D/A conversion. Name your poison??

Rob:)

[Uncle Paul]

You still need to protect the 077 and LE 85's with caps if you triamp. If you don't you run the risk of killing them via groundloop hum or any other LF signal they can't handle. 20 uF is standard for the LE 85, don't know what is best for the 077.

If you Biamp you need a crossover for the LE85 and 077. This is a good way to go, but remember that 20uF for protection. I used a 3106 in a DIY biamped version a long time ago and it worked pretty well.

You may want to retain the upper end of the stock crossover since it looks like there is some contouring there. http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L300A%20Summit%20ts.pdf

[Mr. Widget]

Anyone have experience with Electronic crossovers? I wish to bi-amp or Tri-amp my L-300's. What would I look for? What brands are best? Any Suggestions would be greatly appreciated.


Analog actives don't take into acount specific driver peaks, dips or tilts in driver response a good passive will. There are times that you can't analog active biamp without the custom driver or horn tailoring that is available in a good passive design. In that case you would use both the active crossover for the basic crossover point and a passive network to provide EQ to keep the driver/driver Horn combo flat over it's passband. With digital crossovers you have the advantage of almost infinitely adapable filters that can EQ the driver in it's passband and do the basic slopes all in one. The problem there is another A/D-D/A conversion. Name your poison??While Rob's post is correct, there are two additions I'd like to make. Some of the JBL networks when set to Bi-amp leave the passive contour network in place. The 4430/35 networks for example.

Secondly, the TACT and DEQX units offer preamp options so you can use them as the DAC for your digital source and then contour and muti-amp to your heart's content at very high resolution digital. If your source is analog it is digitized, but even then these units work at a high res format and are remarkably good.

I use the DEQX PDC 2.6P It is my DAC, digital crossover, digital EQ, and analog preamp all in one very good sounding package. It is a bit over $4K but considering all that it does, I think it is a bargain. It actually also offers speaker and room correction as well...

Widget

[Ian Mackenzie]

I've seen a few DEQX crossovers for sale on the diy audio forums . I don't know if thats a good or a bad thing.

I don't believe in auto active crossovers or auto equalisers unless they come with a brain implant.

If you are clever enough or can handle some maths and modelling of active filters anything that can be done in a passive network can be done with an analogue active filter and more. The problem remains none of this is plug and play and you must measure and research you drivers before considering the design of a crossover either passive or active.

[Mr. Widget]

I don't believe in auto active crossovers or auto equalisers unless they come with a brain implant.

The problem remains none of this is plug and play and you must measure and research you drivers before considering the design of a crossover either passive or active.Agreed.

I have found that I am not thrilled with the main selling points of DEQX...the speaker and room correction bits. With speakers that need it I suppose it can be a big help. In my system, I do all of the setup manually and am quite pleased with the results. I know one fellow forum user who had been using the Behringers... after getting DEQX he was thrilled at what an improvement it made.

I use DEQX as a crossover, equalizer, DAC, and pre-amp. I don't think it is possible to get the level of sonic quality that DEQX gives you in these areas for any less than the price of DEQX and most systems at this level are considerably more. I can understand why people would get frustrated and sell their DEQXs... they can be tricky to implement. I heard a couple at last year's CES that did not sound good. In the right hands they are a wonderful and powerful tool.

One very useful feature of DEQX is that you can store 4 complete setups. This is useful in picking crossover slopes and frequencies... on the fly with the remote you can A/B a 24dB 600Hz Linkwitz Riley with an 18dB 550Hz Butterworth or a few thousand other combinations or even EQ settings. This can also be quite useful as an aid in designing passive networks.


Widget

[norealtalent]

All the really great toys are soooooo much money and the difference in quality/price negates using the cheap stuff. I need a corporate sponsor...http://audioheritage.org/vbulletin/images/smilies/scratchchin.gif

[hapy._.face]

Quote: One very useful feature of DEQX is that you can store 4 complete setups. This is useful in picking crossover slopes and frequencies... on the fly with the remote you can A/B a 24dB 600Hz Linkwitz Riley with an 18dB 550Hz Butterworth or a few thousand other combinations or even EQ settings. This can also be quite useful as an aid in designing passive networks. Mr. Widget.


All I can say to that is "wow". That's a pretty kick ass feature!! :bouncy:

Is it like this one? http://www.deqx.com/PDC26P-Preamp.html

I'm at a point where I want to get something like this, but I get lost in the choices. I like this concept in that I'm not married to any particular setup. And, if I find the ideal setup- I could build a passive based on that modeling (then use it on the next project) Pretty cool, if you ask me!! And the cost of configuring the seperates to do what this has integrated (I usually hate the word "integrated")- would be steep. I'm not asking for your personal review MrWidget (looks like plenty are on the net), but what sort of troubles did you encounter while 'implementing' it into your system? How did you correct it/them? Thanks!

[Mr. Widget]

Is it like this one? http://www.deqx.com/PDC26P-Preamp.htmlYes.

As I mentioned... if you read their literature, or talk with them, they think the reason anyone should buy their PDC unit is for it's wiz-bang correction capabilities. To be fair they are really amazing. It is light years beyond a simple auto EQ function.

In my own experience those features have been useful less often than they have been useful though. Of course every system is unique, and if I were using a pair of 2344 horns I would let it generate a correction curve. It will "correct" for a CD horn quite impressively. Since most dome and cone systems and the horn systems that I prefer do not use electronic contouring, I find these "corrections" to be better left turned off.

The origin of this thread was about active crossovers for use with JBL monitors... besides the DEQX PDC, I would look at the high end BSS, TACT, and Lake units in the digital realm. For analog, I like the now long defunct Symmetry ACS-1 crossover. Currently at the high end there is the Pass Labs network, and just below that are the Marchand units.


Widget

[Earl K]

Anyone have experience with Electronic crossovers? I wish to bi-amp or Tri-amp my L-300's. What would I look for? What brands are best? Any Suggestions would be greatly appreciated.

- I wouldn't triamp, I'd biamp while keeping JBLs' passive Bandpass & UHF circuitry in place. These filters invariably include some EQ contouring that just isn't available from standard analog electronic cross-overs ( excepting of course, the digital units mentioned above ). I prefer to stay analog for the time being / hence ; this approach .

- This may mean modifying the N333 to break apart the 3 paralleled passive circuits ( with the one shared input ). I'm a little hazy as to the existing available inputs at the back of a L300 .

- For the top-end circuit I'd use a "Passive-Line-Level" HiPass circuit ( or PLLHP ) built to work into the input impedance of the amp of your choice. I'd place the hipass turnover point 1.5 to 2 octaves below the socalled crossover point ( a L300 = 800 hz ). Therefore, I would set the hipass Fc point somewhere between 200 to 300 hz for the horn/tweeter amp .

- I feel the "PLLHP" is the absolute best bang for the buck investment that one can make to release unused resolution from a playback circuit . ( My PLLHP cost about $ 40.00 cdn and is "DC-Biased" with Polystyrene Capacitors . )
- IMHO, the necessary, electronic 2-pole lowpass can be accomplished by something as pedestrian as the JBL 5234a or 5235 . In fact, I feel it's the musical information that comes out of the horn & tweeter that needs the primary attention ( for resolution enhancement ). I know this is odd since those components are primarily handling only harmonics / but this is how I hear it & what I've experienced .



- I took this step a couple of years ago and now have a hard time imagining a better sounding setup .



:)

[Mike Caldwell]

Hello
Using individual amps for each bandpass be it bi-amp, tri-amp, quad amp, ect
has many advantages.
- the low frequency speakers are directly connected to the outputs of the amp making for a better damping factor.
- you can choose the type of amp you feel best compliments a certain band pass better, solid state for lows tubes for highs ect.
- more output per givin input, your not loosing signel going through the coils and resistors of a passive crossover.
- steeper cutoff slopes are available with active crossovers providing less overlap between drivers, some digital units offer 100db per octave.
- If your system is ran hard you have different limiters for each amp set at different thersholds and ratios.

These are just a few reasons to think about for going to a active crossover system.
Good analog units to get would be BSS, Klark Teknik, TDM, Ashly, ARX. The analog BSS and Klark are no longer produced but can be found used with a little searching.

Like many have said just about any proper passive crossover also has various amounts of EQ and impedance compensation built in for a certain driver, horn, cabinet. So if you would just bypass the internal passive crossover and go bi or tri amp without taking into effect what the passive unit via the active crossover your results maybe less than expected.

The JBL active crossovers had certain cards for different models of speakers that in addition to the crossover frequency also applied EQ.
On the Klark Teknik DN800 you could set it up to do band pass EQ'ing for yuor needs. The BSS 360 can do that as well. With optional cards the TDM also can.

If you convert a passive speaker to bi or tri amp and you leave and contouring components in the system make sure there is no interconnection between drivers to the amp like a common ground or on the positve side through the network.

Mike Caldwell

[L100t Owner]

I am using a Yamaha D2040 active digital pro unit. These can be had used on eBay for considerably less than their $3,000 price tag. It is a stereo 4 channel divider. The left and right channel can each be divided into 4 channels that can each individually be set however you want. I run three way and one full range channel on each side.

Tons of features and I am very pleased with the results. Up to 24 db slopes with L/B correction, time alignment (not so important with bass reflex speakers, but it is with folded horns) parametric eq and digital and analog attenuation. It has so many functions that it was easy to set up (you can mute any individual driver or combination - make dialing it in very easy). You cna also store up to ten programs. All of teh attenuators have motors and when you change programs, they move to the correct position.

The extra ad / da does not hurt. I have a Benchmark DAC1 that reveals a lot that cannot be heard with other dacs. I can still hear the extra detail even with the extra ad/dac conversion.

I an running fully horn loaded speakers (Klipschorns) and the tri amping mates very well with it.

Chris

[Steve Gonzales]

I use a JBL M553 3way active in my triamp system. My Drivers are very simular to an L300- LE14H/LE85-McCauley 800hz horn/076 . When I can afford $2-4K on a better active I might try one, but for now, I'm thrilled with the results using the M553. Definately a great place to start IMO. I would not disregard the great information that was posted earlier in this thread ,but keep it in the ol' cerebral data bank as what to look for ultimately. Good luck in your search, Steve G.

[hapy._.face]

Let's not forget another big advantage to biamping with actives: The amp is only required to amplify the designated frequencies. vs. suffocating the unwanted (post amplified) signal. This = efficiency.

I think Steve's approach is the best, no-nonsense one. Mark: Try splitting the lower from the rest (using a 2-way active M552) and use the passive crossover on the uppers. Simple. Inexpensive- instant improvement.

Speaking of the M552/3: I still have not found out who made these units for JBL. I heard it might be Lexicon. Anyone know??

[Uncle Paul]

Mike,
If it were me, I'd build Giskard's N333 equivalent biased network: http://audioheritage.org/vbulletin/showthread.php?t=166&page=1&pp=15&highlight=l300+charge

I'd build it even if I didn't plan to biamp. Imagine how wonderful an L300 would sound with modern high quality caps and inductors :D

A few differences, though:

I'd go the extra mile and bypass as well - Solens w/ .010 uF Audio Cap Thetas.
Split the circuit into a LF and HF rail so the woofer is separated from the HF/UHF
If you want the flexability to baimp or not use switches to cut out unused portions of the circuit when biamping.
If you are certain you want to biamp only, then simply make a biamp version that omits the unused portions.
If you biamp, get access to an RTA and use it when setting up the electronic crossover.

I'd be inclined to leave the HF rail alone whether or not I baimped. I've lost an LE85 dia due to lack of protection in a biamp config.

Perhaps Giskard would graciuosly give some insight into the HF rail to help separte the high pass vs the contour.

[L100t Owner]

Google the name "Rod Elliott" for an in depth article about active crossovers. A good read if you are considering or just interetsed in active crossovers. There is alos a lot of good info about passive design.

Chris

[Mr. Widget]

The guy is obviously a quack... he has a whole series of articles explaining how tweak cables are based on faith.:blink:

http://sound.westhost.com/articles.htm

On a more serious note... after briefly perusing a couple of his topics, he seems to be level headed and makes some very good points.:D


Widget

[hapy._.face]

Thanks for the links!

Sometimes brilliance follows insanity (or is it the other way around?) I wouldn't know :p

This isn't in reference to any specific forum members, though............................................ .................................................. ...............

[Ken Pachkowsky]

Yes.

As I mentioned... if you read their literature, or talk with them, they think the reason anyone should buy their PDC unit is for it's wiz-bang correction capabilities. To be fair they are really amazing. It is light years beyond a simple auto EQ function.
Widget

I just bought one of the 2.6P (preamp) versions of these. I am curious to see if my Polish brain can figure out how to use it properly.:blink:

I am excited about experimenting with it.

Will keep you posted.

Ken

[Ian Mackenzie]

I just bought one of the 2.6P (preamp) versions of these. I am curious to see if my Polish brain can figure out how to use it properly.:blink:

I am excited about experimenting with it.

Will keep you posted.

Ken

Hey Ken,

Have you looked up the auto ear calibration mode? :rotfl:

Sorry, I read the literature wrong, I meant the room correction mode..oh well same thing when you got massive speakers 10 feet in front of you sez I!!

[Steve Gonzales]

Ken P, I can't wait to read about your findings. BTW, damn good to see both you and Ian posting again. :)

[Ken Pachkowsky]

Hey Ken,

Have you looked up the auto ear calibration mode? :rotfl:

Sorry, I read the literature wrong, I meant the room correction mode..oh well same thing when you got massive speakers 10 feet in front of you sez I!!

Hmm...the comedian from down under:)

Should be interesting Ian.

Ken

[Ken Pachkowsky]

Ken P, I can't wait to read about your findings. BTW, damn good to see both you and Ian posting again. :)

Nice to hear from you Steve.

Ken

[Maron Horonzakz]

Polish??? I thought names ending in SKY were Russion....SKI were Polish. I think sombody sneeked over the border?;)

[boputnam]

I'd biamp while keeping JBLs' passive Bandpass & UHF circuitry in place. That is largely what Greg Timbers suggested would be the optimum route, with a few interesting improvements to the passive. He further suggests that the active crossover have the voltage drive of the original HPF in the passive. I'm trying to get there myself, right now...

And, on a different note:

It is light years beyond a simple auto EQ function. Yea - so is any manual EQ'ing, properly done... :yes:

[Ken Pachkowsky]

Polish??? I thought names ending in SKY were Russian....SKI were Polish. I think somebody sneaked over the border?;)

Yes, I believe you are correct. My great grandparents immigrated from Austria. They ended up in Vienna after fleeing the revolution in Russia. Somehow the SKI got changed to SKY by the Canadian immigration authorities.

Ken

[coherent_guy]

On the other end of the crossover scale, Behringer has a three way, stereo unit, the CX3400, for $159.00 US. They also have a digital model, the DCX2496, for $309.99 US. Links below:

http://www.behringer.com/CX3400/index.cfm?lang=ENG (http://www.behringer.com/CX3400/index.cfm?lang=ENG)

http://www.behringer.com/DCX2496/index.cfm?lang=ENG (http://www.behringer.com/DCX2496/index.cfm?lang=ENG)

What's the word on these units, anyone?

[Zilch]

DCX2496 has been on backorder for nearly a year now....

[boputnam]

What's the word on these (Behringer) units, anyone?You get what you pay for. Actually, in the case of Behringer you are getting less than you pay for, if you can believe it.

There is a good reason why good filters cost good money. That is good, uncolored sound.

-----

OT Section:

A month ago I was gigging - this time on stage - and the HE was using some Behringer crap in the rack. I was on IEM, and kept hearing distortion - bad, and it seemed to be gain dependent. It was really screwing with my singing - at high gain passages when I needed some extra, the sound in my IEM was totally crapping out. I checked my PSM600 gain structure, and everything was nominal - I even changed 9v's - to no improvement.

During a break, I wandered to FOH and spied the rack and saw he had an Behringer C/L insert on my VOX strip. He claimed it was basically "tuned out - it was not triggering". Looking at the face, he was right - threshold was high, and ratio low near 1:1. So, we tried a few more songs, and he reassured it was not firing. My ears told me otherwise. So, I convinced him (always tough for a soundguy singing to convince a HE of anything... :baby: ) to use the console button and release the "Insert" . This way, he could still watch the C/L "not fire" and I could hear the difference with it out of the signal path. The difference was incredible. The sound completely opened, and I quit fighting the C/L.

Just having those filters "in" the signal path, although not triggering, was completely butchering the sound. They must be terribly cheap - they sure sound it. You can hear EVERYTHING with IEM.

No more Behringer, nowhere. If that is all a house has in it's builtin racks, I bypass them all, and "ride bareback". I got a job to do...

[mbd7]

I was wondering why the MSRP on Behringer was surprisingly less than other similar components by other manufacturers. I'm sure glad I bought an ASHLY XR1001 for my electronic crossover needs.

[Mike Caldwell]

Hello
Like Bo said just passing a signal through a Behringer unit will degrade the signal!! I demonstrated that to a friend of mine in his sound system. The reason the Behringer DSP units are on "backorder" is that they were slapped with a VERY BIG fine from the FCC for not getting most of there DSP units certified in the US. I guess that's one way to keep cost down.
The other way they cut cost is to copy good audio equipment designs and then build them with the cheapest parts and labor available, they have been sued by other companies for copyright and patent infringements.

Mike Caldwell

[Zilch]

On Behringer DEQ2496, which is the EQ/RTA, not crossover, the only way to truly bypass is to turn it off, with relays making the direct analog connection. When on, in any of the various "bypass" modes, the signal is still going through the A/D D/A; only the bypassed processing is disabled.

Mr. Widget hears a difference, but I don't....

[Steve Gonzales]

Mr. Widget hears a difference, but I don't....


I imagine that once you've had the TOTL anything, you will hear a difference most of the time with a lesser quality piece of equipment. I use a JBL M553 in my triamped system. I realize that it is not TOTL and can be improved upon, but, it is certainly not bad either. There are members that have tried most everything out there and can speak from that point of view. That has alot of value. What I see too, is that there are alot of models that would satisfy without spending the big $$$ and having the added complexity. I think for the average guy looking for a decent HQ unit, they would have have to take into account how the person recommending these TOTL units arrived at their conclusion. They experimented with a bunch of different units and arrived at that point, because they did so. You have to find a balance between what you need, and then figure out how far you want to push the envelope ultimately. Lots of middle ground there. My best friend says it best: "Knowledge is expensive, experience is priceless". I've built my system by experimenting step by step, improving piece by piece, over time. I have to believe that lesser incarnations of it (my system) would completely satisfy more than a few people, and not be enough for just as many. The great thing about it is that if you are careful and clever about your purchases, you can try a piece and if it doesn't satisfy, sell it most often without a loss and sometimes come out ahead. You'll gain valuable knowledge and be certain of what you really need for your own satisfaction. My point becomes self evident by that fact that these well respected members have very different opinions with the same equipment. The process of finding out what you need can be an enjoyable experience. :)

[Mike Caldwell]

Price alone will not always guarantee better performance over another piece of gear costing less. There are components out there that for the reason of marketing, distribution, brand name acceptance ect. outperform what their price would suggest. Having said that generally the old saying "you get what you pay for" holds still holds true. I think most will agree the in the ever quest for increased quality that once a certain level of performance is reached the amount of dollars spent increases disproportionately to amount of quality increase achieved from that point on. I never really believe anyone who says that there done with their system!!

Mike Caldwell

[Ian Mackenzie]

Mb,

A while back Speaker Builder did a full article on restoring/improving the L300.

It may pay to obtain back issue if still available .

Ian