Thinking beyond passive crossovers...

[Don Richard]

Man, some of these 2 channel guys sure seem to be stuck in the past, don't they? We are now well into the 21st century and it seems the HT folks have embraced the new technology - biamping for subwoofers, Audessey equalization, and surround sound, for example. Some of the 2 channel guys seem intent on recreating a 1950s hifi system and have succeeded. In doing so they miss out on the many advances made in the last 60 years. They appear to be happy with limited performance and I am glad they are. Or are they? I see these folks constantly swapping amps, preamps, phono cartridges and when that doesn't please them they start trying stuff like cables, and magic rocks. Some even try different passive crossover components.

 

The proper way to effect improvement in a sound system is to identify the problem that you are hearing then address the problem. Measurements will help shorten the time it takes to locate the problem. The skill required is getting accurate measurement data and interpreting that data. There are tutorials that will help with that.

 

Measuring the Khorn, Lascala, and Belle will reveal time domain issues caused by path length differences between the horns in those speakers. Tube amps, oil filled capacitors, and speaker wires cannot and will not fix these issues. But they can be fixed using modern technology, with the tradeoff being increased cost and complexity. A loudspeaker processor and additional amplification are the largest cost items, along with the cabling necessary to hook it all up. More measurements along with adjustments to the processor must be made until the curves look OK, then the final tuning is done by ear. Yes, it is an involved process that takes time, and I can see how that can be more than some folks would want to tackle. However, if you have a Khorn read Greg Oshiro's thread on triamping the Khorn:

 

All that is necessary is to get Crown amps like Greg uses, get a Yamaha 2060 processor and copy his settings, and hook it all up. Voila!

 

Want a Jubilee? Use the recommended EV processor with Roy's settings done in the anechoic chamber. Hook it up, turn it on and enjoy!

 

Get some K402s and duplicate Chris's new center design and use his processor settings and you've got it.

 

So, for little more complexity than a home theater system you can have a 2 channel setup that will blow nearly anything else away - B&W, Magnaplanar, Magico, or whatever. A properly aligned horn loaded system is the closest to live music you can get, IMO.

 

 

 

 

 

 

 

 

 

[Marvel]

I would make a guess that the highest percentage of buyers of speaker systems, even of high end systems,  only wants to unbox them, run wires to the amp/receiver, turn it all on and enjoy. They make the assumption that the designer made them to do just that, and I think that is a reasonable assumption.

 

Klipsch sells the Khorn and La Scala with huge time alignment issues, yet they (Klipsch) aren't going to sell a prepackaged system of processor, amps, and everything to make it even more phenomenal than it already is.

 

Embarking on a project like this is not difficult for someone like Chris or Don (or numerous others on here), because you've been working on it for years, trying to understand what it going on. You are no different than a mechanic who listens to an engine and knows what's going on with it. He'll still use all his diagnostic tools to work it out and tweak to perfection, but it is over most peoples heads.

 

Chris, you're an engineer, it's the way you work. Obviously, someone like Richard (coytee) has been able to take his Jubes and get the amps and other gear, plug in Roy's numbers and have it work. Simple? No, even though it may be possible, the folks who genereally buy Klipsch, B&W, any high end line, are really no different than the guy who buys Bose or a little Yamaha HTIB. They just want to plug it in and enjoy.

 

I get where Dean is coming from. I get where you are coming from, but as much as I would like to understand all your charts and graphs, they go right by me. Am I missing something? I guess I am. Would I try it sometime? Maybe... but time, money, other things are going to come first. I'm not a constant tweaker. Life's too short, especially now.

 

I hope this doesn't come off as a rant...

 

Bruce

[Chris A]

(The following is merely a discussion of the notions introduced by the last two posts to this thread.  It isn't a necessary read for those that are interested in the ideas already presented herein.)

 

Actually, if the view that these practices are only for "tweakers", then the HT crowd would still be running with two-channel systems (perhaps with a subwoofer) and there would still be lots of complaints about, "well...it doesn't sound as good as commercial theater". 

 

As it stands, the hardware and firmware to correct for room acoustics and loudspeaker deficiencies are on every integrated amplifier and preamplifier for multichannel use--from very inexpensive ($200) to very expensive ($5K plus).  Room correction firmware and multi-channel sound has been around for over 16 years now.  If you think back to stereo phonographs in the 1970s (probably when most here were indelibly cast into audio), going back even 16 years would put them at the juncture of mono and stereo.  I know that I never willfully listened to mono records if I could avoid it back then...and that hasn't changed over time. 

 

Today, listening to loudspeakers that have been corrected for room acoustics issues is now not only common, it's the rule.  Why some folks today take their loudspeakers and receivers out of a box and just plunk them into a room--wherever--and expect to call that "hi-fi" is a mystery to me.  Hi-fi has always been fueled by "tweakers" from the beginning (late 1940s) and it has never changed. 

 

Now that the firmware/software tools are free and the hardware costs for the test gear (outside of having a PC already--which isn't a stretch) are $22.36 in de-inflated 1975 US dollars, I think that the notion that this is somehow off the beaten path for hi-fi aficionados that frequent this forum daily...seems quite odd. The difficulty in using these packages has been successfully made almost fool-proof even for non-tweaker "plug-and-play" buyers (i.e., using Audyssey, YPAO, etc.), which takes basically zero expertise and knowledge.  The tools discussed here take very little more knowledge, and the purpose of this thread is to break down these perceived notions of complexity into, "yes, even I can do that, too" thinking about the general subject area.  This notion goes beyond "plugging in a little microphone to the front panel and pushing a button", but not by much.

 

The number of people here that spend inordinate amounts of time talking about DC/AC audio circuit theory and impedance concepts for passive networks are subjects that, IMO, are far more complicated than the concepts of equalizing loudspeakers in small rooms for better performance, i.e., real hi-fi. 

 

Perhaps our world views are fairly different.  So risking being labeled a "tweaker among tweakers", I'd say that the notions of "it's too hard" aren't really historically accurate.  YMMV.  Updating your personal technology knowledge to 21st century (most of us have lived in it for 16+ years now) isn't what I'd really call "tweaking".  That term is reserved for a group of people that really do reside on the current state of the art, and that, in my opinion, is far, far away from the practices shown in this thread.  So if you're willing to update your knowledge base to 21st century technology and easy-to-use freeware, the world of "better" hi-fi awaits you.

 

Reminds me of an often used phrase from my prior life: "good enough is the enemy of better"   I'm in the "better" crowd when it comes to hi-fi.  That's why I chose it as a hobby.

 

Back to your regular programming...and the real subject of the thread...

 

Chris

[tromprof]

Going to active crossovers is definitely a leap of faith move since it requires purchasing several pieces of gear including lots of cables, and figuring out how to make it all work. In other words the PITA factor is higher than just setting up a standard passive system. Forum members such as Chris are a wealth of useful information and have made the process much easier for me and I would not go back to a passive setup in my main system, the improvement is drastic even though I have a bit of tweaking still to do. The nice aspect of the electronic crossovers is that tweaking is easy and reversible with just a turn of a knob. At some point I look forward to doing this to my k-horns as well, but I need to stop spending money on trombones first.

[Don Richard]

3 hours ago, Marvel said:

Embarking on a project like this is not difficult for someone like Chris or Don (or numerous others on here), because you've been working on it for years, trying to understand what it going on. You are no different than a mechanic who listens to an engine and knows what's going on with it. He'll still use all his diagnostic tools to work it out and tweak to perfection, but it is over most peoples heads.

 

Folks can also do as you did with your Lascalas and time align the tweeter and midrange by putting the tweeter on the top of the enclosure and physically moving the tweeter until alignment is achieved. The bass horn and midrange horn in the Lascalas are much closer to being in alignment than with the Khorn, close enough to get coherent summation. Would you put the tweeter back in it's original location or are you satisfied with it like it is? Few that have time aligned their systems seem to want to go back. Most of those who have gone back to passives were using low end processors, and you get what you pay for with those.

[Marvel]

Having a 21st  century knowlege of technology has nothing to do with this really. I'll just point back to someone buying a new or used set of Klipshhorns. It's a done deal, and they can hook them up and enjoy. Whether or not you can enjoy them or not doesn't matter. It's a done deal, and that is how the product is sold. The Jubilees were different from the start, so they don't apply here. People want plug and play, even if they can make it better. I would make a guess it would be 99+ percent want the P&P. I wouldn't knock them or be critical of them, that's the main user base and who pays the bills.

[Chris A]

That's the point: plug-and-play users really aren't hobbyists, are they?  This thread is really for those that want to go a little beyond P&P. 

 

Paying the bills, as you rightly have identified, is a phenomenon that Peter F. Drucker talked about in one of his books "Leadership Challenges for the 21st Century".   It has to do with the maturity of the industry and whether or not the supplier supplies entire systems as-is, turn-key. 

 

My experience is that "total integration" still hasn't arrived for those that want better sound quality than what these companies think is "good enough".  That's where the hobbyist comes in.  It's just like home amateur (HAM) radio: it's the tinkering that makes all the difference in the world. 

 

Now don't get me wrong: I'd bet that you know how much I'm focused on music itself (remembering the "missing octave" thread...among others).  I'm not here to tinker for the sake of tinkering: that's not my focus. I also don't care very much about veneer, badges, and whether or not "it's still a Klipsch loudspeaker".   

 

It's the sound that matters.

 

Chris

[Ken B]

Chris, thanks for your thoughtful and informative posts on multi-amping, active crossovers, time and phase alignment, and other techniques of horn rescue. Your comments are enjoyable, intelligent, and intelligible to a non-engineer. 

I have a pair of vintage KHorns, of which only the bass bin remains, refitted with Crites 1526C woofers.  After 20 years’ listening, for my purposes the KHorns had two fundamental problems – ringing, shrillness, honking, and and smearing in the upper treble from the mid-range horn, and a general murkiness - a lack of precision, definition, and placement that I get from my linear-response Snell Bs.  One of the most striking characteristics of the KHorns has been the next-room effect – from the next room, the music sounds LIVE, but disintegrates when sitting in front of the speakers.  This seemed most likely a result of time/phase misalignment of the three drivers, which are widely separated, and possibly interference or distortion associated with the crossovers.

I replaced the midrange horns with Eliptrac 400s and 2-inch BMS 4592ND drivers.  This cured the first problem, and transformed the speakers, as well as providing sunny mornings on the porch sanding, smoothing and lacquering the horn kit, which I highly recommend.

Instead of replacing the crossover and tweeters, I bought a pair of “great” Heil AMT drivers, which are essentially flat from 1700-20K Hz, and being essentially massless, have virtually instantaneous response times, and sound that may well be as clear as light.  I had always wondered whether they could be harnessed, after the spectacular sonic failure of the ESS AMT-1s of my college days.  

The only path to this hybrid solution was by tri-amping, since the efficiency of the AMTs is said to be 99 dB, the BMSs are rated at 118 dB (in mystery 300 Hz horns), and from other forum posts the bass bin and Crites drivers appear to crank out about 102-104 dB (1W/1M??) in a solid corner.  An apparent advantage of tri-amping the system was the ability to use different low-power amps selected for the three drivers and ranges, avoiding phase inversion and distortion, and other benefits (such as 24 dB/octave crossovers) discussed in this forum.  I started with Nelson Pass’s First Watt JFET J2 amp (25W into 8 ohms, 2-gain stage, class A, balanced) and F3 (single gain stage, 15W, class A), and an Adcom relic for the bass.

The combination of the J2 and the BMS/Eliptrac midrange is transcendental, and the transition from the bass is seamless at 400-450 Hz.  The F3 has enough power for the AMTs, and varying the crossover from 1700-2200 Hz reveals the subtle coloration introduced by the horn, and the impact of the harmonics and transients conveyed by the AMT.  IM initial HO, the sound from the mid-horn is so good that the AMT is not a big advantage in the 1700-4K Hz range, even if its reproduction is more perfect on a scan, but I need to spend more time with Pink Floyd, Don Ross and UMIK-1 exploring that question.  Thanks Chris for this valuable insight.

For proof-of-concept, the Behringer DCX is inexpensive and easy to set up and use, but somewhat noisy despite its balanced outputs.  Its huge and compelling advantage is the ability to time and phase align the three drivers, and to adjust the output for disparate amplifiers.  With the DCX, it’s simple to manually adjust the delay in millisecond amounts, along with crossover points and slopes, and to compare the difference.  I agree with other posters.  Once you have heard the KHorns in time and phase alignment, you will never go back.  Instruments pop into place in the soundstage and stay there, with every nuance, floating in a sound hologram envelope.

I would appreciate any comments from experience on the power requirements for a tri-amped KHorn system, assuming that half or more of the power in the crossover system goes to the bass, and that there are significant losses in the passive crossovers.  The 15-inch woofers are big even if the bass bin is efficient, but for driving them directly from an amp, without resistors or inductors, shouldn’t 25W be enough? 

The First Watt class A amps are noiseless, and the DCX is not a realistic long-term option in a system including the Berkeley Alpha USB interface and a comparable balanced DAC/preamp/crossover.  I’m somewhat surprised to hear that posters haven’t been happy with the DEQX, and would appreciate any feedback on the HDP-4, which is supposed to be made with high quality components. 

thanks, Ken

[Chief bonehead]

On September 5, 2016 at 1:23 PM, Chris A said:

 

Now don't get me wrong: I'd bet that you know how much I'm focused on music itself (remembering the "missing octave" thread...among others).  I'm not here to tinker for the sake of tinkering: that's not my focus. I also don't care very much about veneer, badges, and whether or not "it's still a Klipsch loudspeaker".   

 

Really....hmmmm. 

[Chris A]

15 hours ago, Ken B said:

I would appreciate any comments from experience on the power requirements for a tri-amped KHorn system, assuming that half or more of the power in the crossover system goes to the bass, and that there are significant losses in the passive crossovers.  The 15-inch woofers are big even if the bass bin is efficient, but for driving them directly from an amp, without resistors or inductors, shouldn’t 25W be enough? 

It's been my experience that I get a strong multiplier effect on amplifier power that occurs by bypassing the attenuation inherent in passive crossovers/balancing networks and by the breaking up of the pass band by acoustic drivers (a factor of three division of the load).  I'd say the effective gain is somewhere between 4-8 when tri-amping over the use of passives.  I've never had any problems driving the Jubs at volume levels that are cinema reference level or even above, and quite cleanly without loss of dynamics or introduction of audible distortion.  This was using two stereo amplifiers rated at 45W.  The tri-amped Belle and JuBelle were the same story-- power of the amplifiers was effectively multiplied.

 

The cleanness of the presentation of each driver/horn being supplied its own channel is something to experience...for those that haven't heard it.  Perhaps most people do not know how muddy the acoustic drivers+amplifiers can sound when connected through passives with their reactances and nonlinearities mutually forming a very complex result at each driver output.  An acoustic driver+horn connected directly to a single amplifier channel has significant sonic advantages, I've found. 

 

Chris

[Chris A]

On 9/10/2016 at 1:03 AM, Chief bonehead said:

Really....hmmmm. 

Folks worshiping loudspeaker cosmetics and the notion of branding/authenticity over the sound--"it's like arsenic...each new tiny dose doubles the (negative) effect for me".

 

It's the sound that matters. 

 

Without the essential ingredients--technical knowledge and experience, the talent to use those resources, testing, critical listening, and a legacy of more than three quarters of a century doing it and understanding what works--the sound won't be there.

 

Thanks again, Roy.

 

Chris