ACVTIVE (POWERED) CROSSOVERS VS MODDED PASSIVES.

[Fast1]

Hopefully someone will chime in that has done both on the same speaker to compare the two. I have my RF-7s with stock Xovers and performance caps/resistors. I am wondering how this sound compares to a real active crossover? I want to say the Rf-7 uses a 6db Xover and actives can drop things as quick as 48db. Just curious if stepping into active Xovers could show me an improvement???

[mark1101]

I have compared an actively crossed system with ALK ESN passive networks in A/B tests on several occasions in my own home in my own system with the speakers in my avatar and with Jubilee clones. What I found out was this. There is no comparison unless the active system uses a VERY GOOD DSP unit. I used Crown XTI and Behringer DCX2496 units and had terrible results compared to my high end passive netoworks. I know from listening to better active setups using the EV DX38 DSP unit (A MUCH better DSP unit) that significantly better results can be obtained on the active side of things.

I've also witnessed other people's tests using a high end passive vs. active employing the EV DX38 and the results were very close. Very close.

My recommendation is that an actively crossed system is serious business to do right. If you plan on taking the budget route then expect budget results. I wouldn't bother trying it unless you spent good money on good components.

[Islander]

Active crossovers usually go together with bi-amping. The only home speakers that Klipsch has designed to be bi-amped are the Jubilee and the JubScala. Some forum members also have bi-amped MWM/402 setups.

The active crossover used and tested by Klipsch is the Electro-Voice Dx38, which retails for around $1500. A pair of matching high-quality power amps would be connected to it, one to drive the woofers and the other to drive the tweeters. A less expensive alternative is a pair of Crown XTi power amplifiers, which have built-in DSP and can be used as active crossovers.

Going from 3-way La Scalas to 2-way JubScalas with the Jubilee K510 tweeter horn and K-69 tweeter driver was a major upgrade in sound quality, but it was thoroughly researched and developed at Klipsch, as a by-product of the Jubilee program, so there was no guesswork involved. It also cost several thousand dollars. The larger K402 horn is more expensive, of course.

Nothing similar has been done with the Reference Series. Even the Palladium models, which could be called the ultimate expression of the Reference sound, use passive crossovers. If you were to experiment with your RF-7's you'd be totally on your own, working by trial and error.

Active crossovers have already been discussed at great length, so rather than going over it all again, search the forum for active crossovers, Dx38, XTi, Jubilee, JubScala, and bi-amping and see what's involved.

EDIT: I see Mark replied while I was typing this. He's one of the MWM/402 owners and he knows what he's talking about.

[nola]

Mark1101:

I read your reply with great interest. I have KHs and LSs. I have the ALK wooden trachorns (not the 2" throat horns also on the forums) and hope to finally test out the Altec 511 multicell horn and Altec 902-8 ohm driver combo this weekend. I have stock and recapped AA networks and the ALK uni networks.

I am very seriously thinking about trying active electonic digital crossovers and EQs - but that project may be delayed a bit.

I have seen postings here, and at the Altec, audiokarma, audiocircle, etc forums about active crossovers. Your posting is one of the very few that I have yet found that describes any compairson between the less expensive (dbx driverack PA, PA+ (includes room EQ), Ashly 2001, and Behringer 2496 models - $300-450 price range and add $300 more for the room EQ via a Behr DEQ) and more expensive models such as the EV DX38, at around $1280. Before reading your post, I was seriously thinking about the dbx gear.

If you have a 3 way system and subs and a 3 way center - active xovers can get very pricey very fast. Plus, you need a lot of high quality amps.

I had the true pleasure of hearing Colter's ?Jubilee system with the big bass and mid bins and great big (?2-3 feet per side) ?mid/tweeter. It had an active network, but I cannot recall any details of which product he used. Lovely. Canyonman had me over his place. His KHs with the new wooden horn and 2" throat with RTR 15 cm/s source was well, unbelievable. He had ALK Unis.

If we could reduce the numbers of positions for active digital crossover (to reduce cost), perhaps using high end passives (however one would define that):

??? between sub and woofer (although my preamp processor can do that automatically for LFE)

--between woofer and mid

--between mid and tweeter

not sure which area is best to leave passive, maybe we could get the best of both worlds and a "reasonable" cost.

Would also potentially save some $$$ on the amps needed.

Further cost reduction might also be achieved if a 2 way set up, say with the 511s in place of the K400 and K700, sounds nice.

FWIW, others have told me not to bother bi- or tri- amping the Khorns as the time involved and cost would not be worth the minimal incremental gain. But I doubt they tried high end gear such as the EV for the active xover.

Any further thoughts appreciated.

[Coytee]

The active crossover used and tested by Klipsch is the Electro-Voice Dx38, which retails for around $1500.

But you can find used for $500-700

I just bought three on Ebay for $500!!

[Y]

[Fast1]

I am using Audio Cap Thetas in my 7s with the DeanG slight resistor tweak to pull the horns back just a touch.

I have heard a tube pre-amp is a sweat sound on horns. I really WANT to hear tubes on these to see how I like it. From the guitar world, there just is not a comparison. Tubes can be spotted a mile away with their rich (not grainy) tones.

If I decide to go with a receiver, what do you recommend? I looked at Marantz years ago but went with Denon due to reliability reviews. If I go pre amp and add amping to my other 3 speakers, what amps or pres work good? I have been mostly happy with my Rotel but will admit that I want to open it up and see if there are some tweaks I can do with it. I would love to hear an AB comparison to a Bryston.

[Islander]

The active crossover used and tested by Klipsch is the Electro-Voice Dx38, which retails for around $1500.

But you can find used for $500-700

I just bought three on Ebay for $500!!

What, are you going for an all-Jubilee HT, or just investing in Dx38 futures? []

[mark1101]

I totally agree that the very best way to introduce an active system FOR HOME USE is to purchase one that has already been engineered. The biggest issue you WILL run into is the compatibility issue between home audio and pro audio equipment. The active crossover DSP unit will be pro expecting pro levels and impedances. Can you say HELLO BUZZ / HUM / HISS. Building an active system FOR HOME USE is a total experiment, and an expensive one. When I do it again I will be using the pre-engineered solution from Klipsch. I have learned my lesson and have been collecting home audio equipment that has the balanced inputs/outputs and can be used with pro DSP units plug and play (McIntosh). I personally do not like pro amplifiers. I have tried a few and they don't do it for me in the detail category. So I am forced to mix home audio and pro audio equipment and that is where BIG problem #1 will occur when trying to build an active system.

[Coytee]

I've been inspired by the Arabs... I'm planning on creating a Dx38 cartel. Think I can buy them all?

To answer your question... yes and no. I've got three LaScalas and in a perfect world, would love a 5 way Jubilee setup. My room will prevent that (my wife couldn't)

I am planning on burying my LaScalas in the wall in back and using my 3rd LaScala for center. I plan on using the 402 with my center channel so I'll need at least one more Dx. I might consider converting my rear channels to JubeScalas with your K510's and would need another Dx.

I saw a guy selling 4 of them on ebay. Indeed, there were SEVEN at one time for sale. I realized, much like a flood of stocks coming to the market at once that there might be an ability to ****** them on the cheap (downtick).

I nabbed two of them for $500 even (before shipping) and the third one, for.....are you sitting down.... $405!!

I've NEVER seen them trade for $500, the $405 was out & out theft by me. But....the guy shot himself in the foot by flooding the market all at once with them. I was happy to oblige him. I contacted him 2 weeks prior (earlier listing that got cancelled) and asked if he'd consider selling 2,3,4 of them as package. He said he would BUT, he wanted $600 each. I decided I would rely on my instincts and instead of buying 3 for $1,800, I got 3 for $1,405.

[H]

[Coytee]

Can you say HELLO BUZZ / HUM / HISS. Building an active system FOR HOME USE is a total experiment, and an expensive one. When I do it again I will be using the pre-engineered solution from Klipsch. I have learned my lesson and have been collecting home audio equipment that has the balanced inputs/outputs and can be used with pro DSP units plug and play

Amen brother!!

If you're going to do it, do it right

[Coytee]

FWIW, others have told me not to bother bi- or tri- amping the Khorns as the time involved and cost would not be worth the minimal incremental gain. But I doubt they tried high end gear such as the EV for the active xover.

Couple thoughts...

1. There are probably some people that would tell you the ONLY way to listen to Khorns is to triamp them. You can better match amps to drivers, you can align your signals to compensate for the different lengths of the horns.

2. The Dx38 is a 2-in 4-out active...so it's not really suitable for triamping the Khorn unless you bought TWO Dx's and did some creative wiring where each Dx controlled a single channel of the Khorn (1 on each channel). Otherwise, you are shooting yourself in the foot with a Dx and triamping.

[Islander]

To answer your question... yes and no. I've got three LaScalas and in a perfect world, would love a 5 way Jubilee setup. My room will prevent that (my wife couldn't)

I am planning on burying my LaScalas in the wall in back and using my 3rd LaScala for center. I plan on using the 402 with my center channel so I'll need at least one more Dx. I might consider converting my rear channels to JubeScalas with your K510's and would need another Dx.

Smart move! Having ready cash lets you grab the bargains as soon as they appear. JubScala centre and surrounds would sound great and be less bulky and less expensive than an all-Jubilee system, for which you would need a baronial room, as the English put it .

[Islander]

The biggest issue you WILL run into is the compatibility issue between home audio and pro audio equipment. The active crossover DSP unit will be pro expecting pro levels and impedances. Can you say HELLO BUZZ / HUM / HISS. Building an active system FOR HOME USE is a total experiment, and an expensive one.

You've got that right! I had more buzzing and humming than music when I first hooked up my system. After two weeks of trying every combination of connections I could think of without success, I called a pro audio shop that sets up concert systems. Their first comment was, "What! You've got a Dx38 in a home system?" They're an E-V dealer.

Once they believed me, they sent a tech over to get it working properly and it took him three hours and a phone call back to base to get it straightened out. Once it was sorted, I put on a concert DVD for him to hear and he sat speechless with his mouth open for a minute, then said quietly, "It's all there. I can hear everything." He went on to say he'd never heard sound so good outside of a concert.

I'm listening right now and it still sounds great. Actually, even better than it did then, since Roy devised a new program of Dx settings which improved the sound even more.

[mark1101]

That is what happened to me but I had to figure it out for myself unfortunately, and with the budget equipment I tried I was very disappointed. It worked and sounded OK, but not nearly up to my standards even after months of experimentation. Glad yours worked out nicely. It is very good when it is right. Everyone thinks it is so easy. One thing I did was LEARN and when I set it up again it will be right.

I will not be touching my current MWM setup implemented with passives. My active setup will be a second system hopefully with Jubilees completely separate.

[djk]

"The Dx38 is a 2-in 4-out active...so it's not really suitable for triamping the Khorn unless you bought TWO Dx's "

Consider:

Only the mids and highs need delay.

The EV may be configured as a stereo two-way at 4.5Khz with a 24dB subsonic filter at 400hz.

Another inexpensive crossover may be used for the low-pass to feed the woofer.

Remember to factor in the latency of the EV when calculating delays.

Using this method only one EV will be needed.

'Does an RF-7 require a DSP based crossover?'

No, as it does not require delay on the horn.

'Would I bi-amp an RF-7?'

Probably not. I might try and design a new passive network with an all-pass delay on the woofers for time alignment.

[Islander]

Remember to factor in the latency of the EV when calculating delays.

Using this method only one EV will be needed.

I could be wrong, but doesn't the existing passive crossover do more than simply provide roll-on and roll-off for the various drivers? An active crossover would have to provide the EQ of the passive, and setting that up by ear and guesswork would be unlikely to get the best results.

[JL Sargent]

Question. How can a Khorn with passive crossovers sound great yet the only way an active Khorn system can sound great is by delaying drivers? You can't have it both ways. I'm with PWK on this one. I bet you can't hear the difference in time. I've experimented with it both ways.

Let your own ears tell you how much money to spend and what to buy in crossovers. You might decide that $100 Behringer crossovers sound as good as some $1500.00 ones. Why pay extra if you can't hear it?

The greatest think about actives is changing the crossovers on the fly. That and having access to steep slopes which help isolate the different drivers. If you like the sound of a good horn, don't screw it up with a weak 1st order slope that can allow your woofer to join in on the singing.

These are just my personal thoughts on these topics, enjoy.[]

[Islander]

Time-aligning the drivers doesn't make a day-and-night difference, but it does make a difference that you can hear. It's not worth going active for that reason alone, but it is an added benefit.

[wuzzzer]

Brandon,

Would you be able to type the subject of your postings in lowercase letters instead of yelling in caps? Thanks. [Y]

[ZAKO]

Of course there is a active xover that will do 2 way, 3 way, and even 4 way stereo... That is the Accuphase DF-45,,It can do slopes up to 96db per octave..time alignment and delay compensation ...choice of 59 cut off points,,... Plus the matching digital voicing equalizer and microphone DG-38,,, All of this will do everything but wipe your nose... Of course all this will cost more than a pair of JUBS... But what the heck ,,Its cheaper than the cost of health care,.