Are high-end crossovers worth it?

[seanwalsh]

The type A crossover was voiced with current drive. To hear it as intended you would need a current drive amplifier of some sort. I like the explanation here http://lenardaudio.com/education/12_amps_8.html

[beeker]

i believe i already answered the question...if somebody missed it or i didnt answer yet

YES THEY ARE WORTH IT IF YOU HAVE THE MONEY

_cheers!!

[Deang]

The type A crossover was voiced with current drive. To hear it as intended you would need a current drive amplifier of some sort. I like the explanation here http://lenardaudio.com/education/12_amps_8.html

I only have a cursory understanding of amplifiers. Some sites say tube amps are voltage devices, while others say they are current driven. While amplifiers certainly sound different, and some sound better than others with these speakers, I can also say I've heard some tube amps fall flat compared to some well executed solid state. No matter, in the end, it will be the network that has a larger impact on the sonic signature of the loudspeaker than the amplifier you choose.

http://www.atma-sphere.com/Resources/Common_Amplifier_Myths.php

http://electronicdesign.com/analog/tubes-versus-solid-state-audio-amps-last-word-or-house-fire-part-2

Edited May 25, 2014 by DeanG

[Deang]

Mike -- just saw your response above.

"I wrote an interesting reply, but I realized that I would like to hear from you first as to what you think is happening before I bias your response. You're the designer, you tell us why it's supposed to sound better..."

I don't understand what it is about your reply that you find interesting. It's just an admission that you can't hear the difference between two completely different filters!

"How would you personally describe the overall sound quality of this particular experience?

The initial sound was strident and too bright. After Craig set the volume, someone else went up to the system and turned it up. The people sitting in the chairs in the front of the room got up and moved to the back of the room.

"To what do you attribute the difference in sound?"

Mil spec film and foil polypropylenes instead of metallized polyester junk, a bandpass filter, and taking 3dB off of the midrange. The LaScala is not a Klipschorn, and doesn't have the low end output required to achieve the same level of balance (perceived) with the top section running wide open -- especially with no boundary reinforement, which was the case that evening.

I had brought the networks for Craig, as they were part of the payment for the amps he was building for me. We saw everyone in the back of the room, and we stepped out into the hallway. He asked me to ask Trey if I could load the networks up. Trey said he didn't care as long as I didn't blow his drivers. 20 minutes later, Trey's at the front of the room with about a dozen other people, taking SPL readings and shouting over his LaScalas. Incidentally, Colter has been running the same basic circuit for over seven years. Now, I think we should both be able to agree that Michael has a few things over there with which to compare, right?

I guess this is the part where you "bias my response"?

Edited May 26, 2014 by DeanG

[DrWho]

The actual response I wrote out is at work, but I'll go ahead a paraphrase while I wind down from today's celebrations / memorials...

It actually took me a while to remember which gathering was being referred to all those years ago, but what I do remember is trying to be nice about the volume/xover issue. I think the Klipsch following falls into two camps: those that like very loud music (to the point of feeling the snare drum in your eyes), and those that like low distortion and exploring the more minor nuances in music. In many ways they are similar goals - but at the end of the day the SPL levels are very different. The volume in that hotel was painfully loud - and certainly enough to have caused me permanent hearing loss (thanks for that btw). I absolutely hate volume creep. I also hate the lascala as a stand-alone speaker. Combine the two with an overdriven speaker, and there was a room being filled with absolutely garbage sound. I could achieve the same hash with direct radiators at a much more palpable 100dB SPL. A minor touch of EQ doesn't register as a big change in my world when there's that much garbage happening. In other words, it sounded like garbage before and after - therefore it was fundamentally the same in my book. Go back and read my original post and you'll find these sentiments ringing throughout - it was simply an uncontrolled experiment wrought with inexperience. Do we really want to make such scenarios foundational to our viewpoints?

The group of people I was standing with in that back of that room included guys like Blanchard - who I have a huge respect for both their musical acumen and engineering talent. Mark made an interesting point later that evening about how the electrical impedance of a network is only significant over a narrow range of frequencies - and that narrow range is really the only range where parasitic behaviors tend to manifest themselves. I was trying to share some of the things I learned from those conversations - and today looking back, I'm reminded at the huge insights Blanchard was freely sharing with me (a young punk college kid at the time). Today I totally see it in a new light, but would still stand behind those broad concepts. The idea of impedance - when you really understand it - is such a beautiful way of describing electrical behavior (especially parasitics).....it really takes years to truly appreciate what is being described here. It's not just ohm's law, or pumping numbers into a calculator.

One other thing that still bugs me about the xover modding crowd is the lack of data - even all these years later, the "mountains of data" alluded to amount to nothing more than an on-axis frequency response - at best. I tried to tally it up and I think I've designed a few hundred xovers to date - and taken "mountains" of my own data. Some xovers have been implemented better than others, but over that time I've done a lot of research and found a lot of people discussing their experiences too. We get into conversations or read articles about things like polar steering, power response and balancing on-axis versus off-axis response, the blending of polars and distortion, signal-alignment.....all the way down to the small things like the quality of different kinds of inductor magnetics and capacitor dielectrics, or the effects of damping on a non-linear impedance response and so forth. It often overlaps into speaker design - whereby the realities of xover design impose certain requirements on the speaker - even at the expense of other acoustical properties. I greatly enjoy exploring these tangible areas, but also can't help pointing out the relative audibility thresholds. For example, the difference between polypropylene and polyester is very small compared to things like time-alignment, or the horn throat distortion causing the honk in the old heritage. If you're hearing me correctly, I very much believe xovers have an audible component to them. I have just never heard you discuss any of these topics that other circles and myself claim to have much larger significance. Why do I bring it up? Because I'd love to see you and others implement some of these tricks...it's not like I'm in any competition here.

Btw, the reason you get push back from the speaker designers at Klipsch is because they realize what they could do with another $200 in budget on their end. It's not like they're unaware of and haven't tried the different kinds of capacitors, inductors, autoformers, transformers, resistors out there....and it's not like they don't enjoy music either. Just look at a product like the Reference series where the improvements in performance were achieved via acoustic means - and the same basic xover approach was adopted across the lineup. You could throw $10k into the RF-3 xover and not achieve the performance of the RF-5 with its stock xover....let alone a speaker from the Palladium line. One of the problems with trying to make philosophical generalities is that there are always exceptions to the rule - and in the case of this thread, the original speaker being discussed was an RF-3. I very much had that in mind when writing my original response - different price points need to be abstracted differently.

In light of this very old thread, I think my untenable position can be summarized with the question, "when do crossovers matter?" - and I might extend that to include identifying one's goals in listening.

[ClaudeJ1]

I also hate the lascala as a stand-alone speaker.

I take it that you mean without a PROPER subwoofer? If that's the case, I wholeheartedly agree. I'm not a fan of a 140 hz. peak, with people calling it "fast bass." I'd rather have "Fat Bass," thank you.

Below 104 hz. which is the cutoff for a 2.7 foot horn, the bass drops like a rock and there's almost 2 1/3 more octaves to even get close to 20 hz.

Subs need crossovers too, but when the parts get that huge passively, it seems that active is the way to go.

I remember Blanchard showing the Palladium Xover schematic. It took a lot of virtual prototyping and tweaking to deal with the driver material anomalies in the top of line speaker. It was not a trivial task, even for someone with all the tools and talent.

[Deang]

"... but what I do remember is trying to be nice about the volume/xover issue."

I'm not sure what that means. I had nothing to do with the volume levels, and neither did Craig. All I know is that after I put the new networks in, the volume started going up. The point I was trying to make was that before I put them in, no one was expressing much interest in listening to the music (based on how it was sounding at the time).

"I think the Klipsch following falls into two camps: those that like very loud music (to the point of feeling the snare drum in your eyes), and those that like low distortion and exploring the more minor nuances in music."

You'll get no argument from me on that point.

"In many ways they are similar goals - but at the end of the day the SPL levels are very different."

If one is trying to get their system to play as loud as possible without bleeding their ears out, and the other is shooting for good tone, musicality, and the lowest distortion levels possible -- the goals are very different -- and what you need to do to get to each are quite different.

"The volume in that hotel was painfully loud - and certainly enough to have caused me permanent hearing loss (thanks for that btw). I absolutely hate volume creep."

Though the volume started to go up, it was still at a reasonable level. I mean, I was about 3/4 of the way back into the room talking to people and getting information for orders. At the point that the gear was changed out and Trey brought out an SPL meter to demonstrate the maximum SPL capability of the LaScala, several left the room, including Craig and myself.

"I also hate the lascala as a stand-alone speaker. Combine the two with an overdriven speaker, and there was a room being filled with absolutely garbage sound. I could achieve the same hash with direct radiators at a much more palpable 100dB SPL. A minor touch of EQ doesn't register as a big change in my world when there's that much garbage happening. In other words, it sounded like garbage before and after - therefore it was fundamentally the same in my book. Go back and read my original post and you'll find these sentiments ringing throughout - it was simply an uncontrolled experiment wrought with inexperience. Do we really want to make such scenarios foundational to our viewpoints?"

You're confused. How are you coming to these conclusions? We had 60 wpc on those loudspeakers (Craig's tube amps). Volume levels eventually hit around 90, and people had actually moved from the back of the room to the front of the room to listen, and it was sounding really good. Craig and myself were both receiving complements on the sound. There was no "experiment". At that point, it was just a decent system playing music. Your issue seems to be with Klipsch, because while Craig and me were gone (smoke break), Craig's gear was substituted with some Aragon equipment and an SPL meter. Now, I can tell you this, and you can believe whatever you want -- but those speakers would never have hit those levels without clearing the room out using the original networks.

"One other thing that still bugs me about the xover modding crowd is the lack of data..."

That's a fautly assumption. You seem to think all of this stuff is created in a vacuum. There's a significiant amount of testing performed on some the aftermarket products and modifications. In fact, it might surprise you to learn that at times, even Klipsch has taken a passing interest in some of the things that go on here. What a shame that there is such a disconnect between what's going on and what some think is going on.

BTW, the LaScala can sound very good as a stand alone loudspeaker, it just needs the corners that PK intended for it, and a couple of dB knocked off the top if you're going to drive it hard.

Edited May 29, 2014 by DeanG

[Schu]

I think... and I am sure some will agree... there exists massive amounts of data, empirical evidence/data, that would help to determine a XO's quality and influence on finished sound, post modification.

[CECAA850]

Are high-end crossovers worth it?

Yeah, and Deans aren't too bad either.

[beeker]

Yeah!

[mike stehr]

"I think the Klipsch following falls into two camps: those that like very loud music (to the point of feeling the snare drum in your eyes), and those that like low distortion and exploring the more minor nuances in music." You'll get no argument from me on that point.

Shouldn't there be a third camp here that likes to do both?

[cradeldorf]

I'm a third camper.

[Deang]

I think most are, but you usually find yourself on one end of the spectrum or the other for most of your listening. I like it loud too on occasion, but it sure ain't like it used to be. I think it's more challenging to get great sound at lower to moderate volume levels, and when you hit that sweet spot, well, that can be really magical. "loud" can be fun, but only for a handful of songs before it starts to wear thin. Now, you can build a system that plays loudly and cleanly, and it sounds awesome, but it almost always instantly rewards you with ringing ears and tinnitus. Where is the fun in that? What's cool is 80 - 85dB peaks at 9 o'clock at night, with a vanishingly low noise floor, in quasi-nearfield - kicked back and letting the music take you away with its ambience and texture. Now, I love a few cuts off of a great CD tearing loose - but that's not where I want to live.

Edited May 29, 2014 by DeanG

[mark1101]

^{When Dean hears 80-85........it's actually playing at around 100. ..........so yeah you need the better crossovers.}

[DrWho]

"One other thing that still bugs me about the xover modding crowd is the lack of data..."

That's a fautly assumption. You seem to think all of this stuff is created in a vacuum. There's a significiant amount of testing performed on some the aftermarket products and modifications. In fact, it might surprise you to learn that at times, even Klipsch has taken a passing interest in some of the things that go on here. What a shame that there is such a disconnect between what's going on and what some think is going on.

BTW, the LaScala can sound very good as a stand alone loudspeaker, it just needs the corners that PK intended for it, and a couple of dB knocked off the top if you're going to drive it hard.

So where are the polar response measurements of your xovers? That is afterall, the most straightforward measure of how well two drivers are summing acoustically....and isn't that the primary goal of the xover?

The difference for me today is I've taken these measurements and have realized just how delicate of a balance that is - and how quickly things can get thrown off when you don't pay special attention to those behaviors....and then you get into these voicing games where you're offsetting performance in other areas because you're trying to find a balance to a problem that doesn't need to exist in the first place. Or maybe I'm just too obsessed with the sound of drums and in particular the influence this has on the snare - or at least that's one place where I think some dominant sonic signatures are most easily perceived.

Btw, the lascala in a corner doesn't fix it's lack of bass problem...at least I've never been satisfied with it.

[Schu]

So where are the polar response measurements of your xovers? That is afterall, the most straightforward measure of how well two drivers are summing acoustically....and isn't that the primary goal of the xover?

doesn't that more notably measure lens characteristics amongst other things?

Edited May 30, 2014 by Schu

[Deang]

"So where are the polar response measurements of your xovers?"

You mean the in-network response with a given horn system. Please keep in mind that "my" crossovers are PWK's crossovers, so those plots would be in the possession of Klipsch. I do build one network which is just a modified Type AA. It lifts the tweeter off the autoformer and uses a swamping resistor to allow for adjustable attenuation. Like the early networks, the horns roll off faster than the filter dictates, which means the horns are determining the acoustic crossovers, not the network. The K-400 horn collapses directivity in the vertical plane, so it's not hard to imagine what that might look like.

If you want to see polars of Dave and Al's Eliptrac 400 horn and the DE120 tweeter, you can see those on their websites. Tests were done under controlled conditions and may have included the use of a chamber. I don't know if the measurements included a network or not. Al did waterfall plots for the tweeter, but I don't know if he put them up or not.

"That is afterall, the most straightforward measure of how well two drivers are summing acoustically....and isn't that the primary goal of the xover?"

Only if you're designing LR-4 with time-delay, which certainly isn't the case here, where the primary purpose is to connect the drivers together and produce flat response with low summation error over a range of frequencies, or said more simply, to allow the drivers to work smoothly through the transition. Good polars/power response wasn't a "primary design goal" 60 years ago. So sure, because of the non-coincidence of the drivers, there are lobing errors and some other issues. However, that doesn't mean they don't sound good. In fact, they are often preferred, as is evidence by those who have replaced the newer Klipsch networks, and yes, even Al's ESNs -- in favor of the older designs. Most haven't heard a simple first order electrical filter built with "overpriced audiophile parts" on these loudspeakers, but when they finally do, they find out the same thing Bruce Edgar did, "

"I started out using 6 dB crossovers because they were just the simplest to do, and they seemed to work. Klipsch had said in his early experiments that he had started with second-order crossovers during World War II. As his capacitors went bad and he couldn't get any new ones, he changed his crossover to a first order and found out they sounded better, so I started off with 6 dB crossovers. In the mid 80s, Bob Bullock, who is one of the editors of Speaker Builder, came up with a number of articles showing how to design all different order crossovers, and so I decided to try them. I built up some second-order crossovers and put them into the club system. I didn't hear a whole lot of comments about it, but when I switched back to first-order crossovers, everybody came up after the demo in the club meeting and said how good the system sounded. That told me right away that first-order crossovers sound better on horns.I designed my horns so that the bass horn would roll off at the point where the midrange horn was turning on and the midrange horn rolled off where the tweeter was turning on. Those mechanical rolloffs complement each other, so when you put in a first-order crossover, it essentially acts as a traffic cop and keeps the impedances proper. But the mechanical rolloffs also have a rapid phase change. In the pass band, the horn response is minimum phase, like most loudspeakers, but at the point where they start rolling off, near the flare frequency or at the point where the mass is rolling off the response, the phase changes at those points are very fast. A first-order crossover doesn't mind, but a second-order crossover or any higher-order crossover can't handle all that phase change.So, just by trial and error, we can essentially confirm what Klipsch found out earlier, but you have to be able to do those experiments to really find out what is the truth, because 90% of the horn literature is pure garbage. It's one author regurgitating what another author said. In fact, one of the amusing things I've found are errors in the mathematical terms that go through several different textbooks, being repeated because they assume that first guy did it right. The following authors just copied the equations and never really checked the math. When people ask me "How do you design horns?" I say that you have to do the experiments. I can go out and buy LEAP software and design a bass reflex speaker, but you've still got to go through trial and error, building boxes with drivers and finding out what things really matter. There are all sorts of things that the textbooks just don't tell you." http://www.positive-feedback.com/Issue4/edgarinterview.htm

For everyone else:

"The topologies in Fig. 3 are for power, rather than preamp levels, using coils. As the textbooks are fond of saying, calculation of the values is left as an exercise to the reader. The 6dB/octave and the inverted 12 and 18dB/octave examples yield sums which are quite flat, and remarkably, we see that the 12 and 18dB/octave cases both yield identical amplitude and phase results. Of all these filters only one, the lowly 6dB/octave crossover has both accurate amplitude and phase response when the outputs are reassembled." -- Nelson Pass www.firstwatt.com/pdf/art_coherent_xvr.pdf

"The bad news is that when you cascade two crossover filter pairs to create 3-way crossovers (passive or active) they tend to run into summing problems right from the start. Even ideal electronic summation often results in response aberrations that strongly depend on the spacing of the two crossover frequencies and the filter type. As a rule, the more widely spaced the crossover frequencies the more accurate the summation. As you move your crossover from the ideal world of electronic summation to the much more difficult arena of acoustic summation the problem grows. You now have to consider not just the responses of the crossover filters but the responses of each driver in combination with the crossover filters. There is one wonderful exception to the generally nasty behavior of 3-way and higher crossovers: the 1st order Butterworth crossover. The ideal performance of this simplest of all crossover types holds up even in 3-way and higher crossover types. The electronic summation characteristics are absolutely perfect. This crossover sums to deliver not only a flat frequency response but a flat phase response as well, regardless of the complexity of the crossover. This essentially perfect behavior of the first order filter pair once led me to use them for a 13-way crossover I designed for a consulting client in the recording industry...use 1st order Butterworth crossover types for as many of the crossovers in your multi-way system as possible."-- John L. Murphy, Physicist/Audio Engineer http://www.trueaudio.com/st_xov_1.htm

www.rane.com/note160.html

1st-Order Amplitude Response
Figure 9 shows the flat amplitude response resulting from summing the LF and HF outputs together. This is called constant voltage, since the result of adding the two output voltages together equals a constant. The 1st-order case is ideal in that constant power also results. Constant-power refers to the summed power response for each loudspeaker driver operating at the crossover frequency. This, too, results in a constant. Since each driver operates at half-power at the crossover frequency, their sum equals one--or unity, a constant.

1st-Order Phase Response
Once again, Figure 10 shows the idealized nature of the 1st-order case. Here the result of summing the outputs together produces 0° phase shift, which is to say that the summed amplitude and phase shift of a 1st-order crossover is equivalent to a piece of wire.

.

1st-Order Group Delay Response
Group delay is the term given to the ratio of an incremental change in phase shift divided by the associated incremental change in frequency... Figure 11 shows the group delay response for the Figure 8 low frequency output...The summed response is, again, that of a piece of wire...For clarity purposes normally only the step response of the LF network is shown. Nothing is learned by examining the step response of the HF network. A step response represents a transition from one DC level to another DC level, in this case, from -1 volt to +1 volt. A HF network, by definition, does not pass DC (neither does a loudspeaker), so nothing particularly relevant is learned by examining its step response...it begins at zero, passes the high frequencies as a pulse, and returns to zero. The HF and LF outputs are the exact complement of each other. Their sum equals the input step exactly as seen in Figure 12. Still, we learn everything we need to know by examining only the LF step response; looking for overshoot and ringing. From now on, just the LF output is shown...The 1st-order case is ideal when summed. It yields a piece of wire. Since the responses are the exact mirror images of each other, they cancel when summed, thus behaving as if neither was there in the first place.

Edited June 9, 2014 by DeanG

[cradeldorf]

Question: Does replacing all the inductors with much larger wire inductors so there is a lot lower DCR change the ability of the network to do it's intended job? I'm asking because the little trinket inductors on my crossovers kinda seem like a joke.

Also could somebody explain the midrange inductor on the far right of this picture? I understand the inductor part but don't understand the 2 parallel lines next to it?

Edited May 31, 2014 by cradeldorf

[DrWho]

More fluff, no data. I've seen all these anecdotes before.

Cradeldorf, changing the Q of an inductor changes its behavior around the knee. In other words, changing your winding structure to give lower DCR will change the originally intended frequency and phase response. Determining if that's a change in the positive direction requires more information.

[Marvel]

... don't understand the 2 parallel lines next to it?

The parallel lines represent the core.

Bruce