By Brad Paulsen
I love speakers, absolutely love em. I love touching them, moving them, buying them, building them, and most of all, listening to them.
They hold that special place in the audio chain where electronic energy is turned back to mechanical energy, the hardest task of any link in the chain.
Obviously there are zillions of speakers for sale out there. Big ones, little ones, dynamic drivers, ribbon drivers, electrostatics, 2-way, 3-way, with powered sub, passive sub, and on and on and on.
But the 1 big mystery to me is crossover technology. I can not for the life of me figure out why speakers with shallow slope crossovers like 6db/octave, sound so much more real to me than ones with the current rage of steep slopes like 24db/octave and even steeper. The mathematicians tell me they shouldn’t.
Having the luxury of constantly traveling the whole country visiting the premier audio dealers of America I get to constantly listen to systems, old systems, new systems, and the latest and greatest. Great gig if you can get it.
And it just keeps happening to me, invariably when a demo just knocks my socks off, gives me goose bumps, touches my soul and ignites many memories of musical past experiences, it’s invariably these speakers with “shallow crossovers”.
They seem to deliver these huge images, flowing sound and just a texture and humanness to them that my senses and emotions react too, very much the same feelings I get from a live performance.
Conversely I often get plunked down in front of some new very expensive, latest and greatest speaker with these so called phase correct 24db/octave crossovers, notch filters, etc., and it’s just all so sterile, unemotional, like watching TV in black and white instead of color.
I know the specs are better, I know all the measurable parameters including phase are better, but doggone it, they just don’t sound better. Just more sterile in a very analytical way, almost more machine than human.
I love technology, but I love enriching experiences too. I can only come to the conclusion that maybe we just don’t have the technology to measure and quantify all the differences that actually occur.
They told me in 1983 when the CD came out that it was perfect and measured perfect. Wrong, 30 years later they are still improving it’s sound and discovering things they didn’t know back then. Clearly the industry missed that one. Ignorance isn’t always bliss.
8 years ago when the big “digital amplifier” rush was on and almost all manufacturers jumped on board as the cost/performance ratio appeared on paper so much better than analog. Specifications clearly showed how superior these amps were going to be. Fast-forward to today and almost every high-end amplifier manufacturer has abandoned digital amps. Truth of the matter is they were awesome on paper, but sonically sucked.
So speaker crossovers with minimal parts to chop, delay, color, and constrict the original signal. I am a firm believer every single component we run signal thru, in someway degrades the sound; that I know to be true.
Who says we can take a human voice and chop it apart thru about 40 capacitors, inductors, resistors, and spin the phase like a roller coaster, and just magically put it back to together with no loss of quality.
While my eyes see the specs, I have to let my ears be the judge, and not let my mind be swayed by arguments from an industry that has shown they often just don’t really know but sell us like they do.
I’ll take my speaker crossovers over easy please, not scrambled.
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Gannon
Brad,
Thank you for this. I concur, although I’d add a few things…the 1st order x-overs are usually the most engaging, but I’ve also heard some using what I’ve heard unofficially called quasi-second order…where they shift into 12dB per octave after the first octave outside the desired passbands, for increased power handling. I’m a big fan of the Zobel impedance stabilization circuitry, too, it doesn’t take the life out of the music and allows most amps to not get near any freakout loads.
I’ll never forget the lecture I got from a very famous speaker designer when I dared question his use of 4th order crossovers. This guy has his own drivers manufactured to his specs, with some of the most expensive test facilities in the world…and I’ve never been able to really get interested in anything he’s ever made. They are NICE, don’t get me wrong, but they are decidedly not anything I would purchase.
I have a client here in Michigan who purchased a complete set of what is known as the most expensive speakers in our market…they made a $90k flagship for a while, and when they updated it to a >$130k model…he put the others in back for his surround speakers! Driven by Levinson electronics…with the best of everything…and I can barely stand being in the room. It is the single most expensive home theater I’ve ever experienced. But he wisely stays with tubes for his video, which is why he needs me! LOL.
See you next week.
Cheers!
John J. Gannon
Detroit
Brad Paulsen
Sounds like what I have lived thru. I believe I know exactly who the “famous speaker designer” is you refer too. He’s been a very good friend of mine for 25 years, I just have never put a pair of his speakers in my house yet, as brilliant as he clearly is. I concur with you about being overpriced and underwhelmed. I have sat in front of many a pair of $100K speakers in a system hoping to experience the pearly gates, only to be completely unimpressed and walk away thinking, boy if customers think this is what they get for $100K its a sad state of the industry. Thanks for the reality check. I am also thinking you might be the John Gannon I spent many a day dissecting audio back in the B&K days. Glad to see endeavoring to save the world from bad sound, thanks John.
Ben Booth
John:
I think most audiophiles begin there “obsession” very early on – and for many, it has at least as much to do with the gear as it does the music itself. For me, it was speakers all the way. As a twelve-year old kid, I remember riding my bike to the local Richman-Gordman retail store, where there was an impressive display of Venturi speakers and Marantz electronics. I think I actually dreamed about those Venturi speakers (I wanted them really bad).
I recall my first AR-7 speakers when I was a mere teenager. I would remove the grill fabric and just sit there watching the bass drivers move in and out….What a geek!! I still love dynamic drivers and acoustic suspension enclosures. I’ve had stats and planners, but I always seem to come back to drivers and “boxes.”
I am, however, at a loss when it comes to crossover technology. While I like the sound of certain speakers and dislike others, it generally has nothing to do with price. Perhaps I too like the shallow slope…or maybe it’s the steep slope I embrace. I haven’t a clue…?
Could you provide some examples of speakers that utilize a shallow 6db/octave slope and some examples of others that utilize a steep slope (e.g.: 24bb/octave). This will be very useful for me in understanding just what it is I like about speakers (besides the way the bass drivers move in and out!!!).
Thanks.
_Ben
Brad Paulsen
That’s a great story Ben ! BIC Formula speakers, boy that takes me back. Formula IV’s with red, white and blue logos on the front. Too cool. I’d love nothing more than to spill my guts on my own “favorite” speakers, but honestly being in the industry all my life, I should probably not at the risk of alienating some of my best friends. Funny, I am tight with a bunch of the top speaker designers of today, talk, break bread, commiserate on the old days gone by, but have never bought their products. Ha. Go on line and take a look at some of the spec sheets of the speakers you listen too, the spec sheets will tell you the crossover topology. Shallow slope generally being 6db or 12db, and steep usually starting at 24db and going up. You can extrapolate your own conclusions. I won’t say I believe crossovers are the only parameter to be concerned with, as it’s not, but it’s in my opinion the most important parameter that has gone astray.
Ben Booth
Thanks Brad!
Ed S
I yanked my first speakers 45 years ago out of junkyard cars and installed them in cardboard shoeboxes. Since then I’ve owned all types, dynamic, ribbon, stats, planars, Walsh… You name it. Loved working my way up the AR line: 4x, 2ax, 3a, LS-9. Then Infinity, Carver Amazings, Acoustat 2+2s, Martin Logans, Red Rose, Newform Research ribbons, and finally Maggies. I suppose the best crossover would be no crossover. The best, to my ears, have been the Magnepans. Augmented with dual Hsu subs when lowest notes are desired. I believe their x-overs are low-order, single cap affairs. And I’m using the bottom of the line MMGs, that go for $550/pair. I think they are the best things I’ve heard, since the first car-speaker shoebox I made, that is… You never forget your first!
Lee Cobb
Its nice to find others who hear what I do. It seems that most of the high end magazine reviewers don’t. I still read ‘em, but the ears are still the best test for sound quality.
One of the things that completely destroys the sense of “reality” during a listening session is when the sibilance on a voice doesn’t “line up” with the fundamentals of the note being sung. The same thing happens with instruments that produce two simultaneous sounds, like the snare drum. Most loudspeakers just don’t get it right.
In order for the signals from the woofer and tweeter to add together and form an identical copy of the original electrical waveform, two things must be present.
Firstly, a first order, or similar (eg. constant voltage), crossover must be used. Secondly, the distance from the acoustical centers of the woofer and tweeter to the listen must be the same. Actual, D’Appolito suggested the WTW configuration which, when done correctly, can make the effective acoustical centers co-incident. For a loudspeaker to make a convincing image (to my ears), both these conditions have to be met.
Using low order crossovers means that a lot more care in driver selection and integration must go into one of these designs. Speaker design artists like Vandersteen have great success at doing this.
Brad Paulsen
Aw it’s so nice to hear others chime the same song. Carver Amazings, one of my all time favorite speakers that almost no one in the country knew how to set up in a room because of the dipole woofers. Good memories. D”Appolito rings true to my heart also. And I would say most speakers that use that technology haven’t been my favorites, but ones that did it right are some of my favorites in my past. A brand back in the 70′s was onto the advantage of a similar driver set up, while not exactly D’Apollito since that came in the early 80′s, made some amazing stuff. RTR a brand many people didn’t know about created one of the most intense cult followings I have ever seen, before or after. That coupled with their work in building electrostatics panels for themselves and most everyone else including the Infinity Servo static 1A, made them a legend. Back in 1978, a pair of their 600D’s columns and ESR-15 Electrostatic add on cubes, that was the bomb. Shoot while I am praising a long gone speaker company, read Jim Whiney of Magnepan fame who in an early interview said a pair of RTR electrostatics was what blew him away and help motivate him to start Magnepan. Yup, good old days.
Lee Cobb
Brad,
I’ve always had to shop for my speakers and components on a tight budget. In the college apartment we had a pair of Infinity Monitor Juniors with the transmission line loaded woofer. It made huge, coherent sound for a (relatively) small speaker. Mini-monitors weren’t known at the time. The upper bass and lower midrange clarity was so good it sold me on TL loading. I later had a pair of Spica TC-60’s. Today they are not in my main system, but I still use them as the front speakers in my simple home-theater setup. Both these speakers use low order crossovers designed to produce an acoustic waveform that matches the electrical input. I remember listening to the planar-magnetics like Apogee at the time. The transient response was delightful, but the sound was “phasey”- I couldn’t live with them.
Most of the speakers I liked, I couldn’t afford. In the 80’s I built a pair of WTW speakers with the tweeter recessed so the acoustical centers matched. I used Peerless 6.5“ polypropylene woofers and a Polydax 1” dome tweeter. The woofers were TL loaded. The crossover was a simple series connected first order at 3 kHz with a Zoebel network. I loved them. Those speakers have undergone a lot of changes since, including the use of the crossover type mentioned by John Gannon. The use of overlapping higher order crossovers in a minimum phase configuration was suggested by Tim Sandrik in Speaker Builder #4/1998. The speakers now have newer Peerless woofers and a ScanSpeak tweeter. They aren’t perfect, But they do everything well. I’ve heard some speakers that top them in one or two areas, but haven’t heard any that top them in everything. They probably exist, I just don’t get many invitations to listen to stuff I know I can’t afford. Thanks for letting me reminisce.
Lee
Brad Paulsen
Wow Lee, Spica, that sure brings back memories to me. TC-50′s and TC-60′s. Cool looking and so good sounding. I sold tons of them. I remember taking a pair of TC-50′s and hooking them up with a pair of Velodyne Servo 15 subs. That was one fun sound. Smooth but knocked the walls down. I remember putting Flim and the BB’s on and just watching people lose it. Thanks for sharing.
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hearnow1
I am still not sure how to tell the crossover on my speaker. The manufacturer does not give the slope of the crossover in any of the specs. Are there any other clues as to what type of crossover they might be using, since I am not able to listen to as many speakers as you and then try to compare them on the basis of crossover type which I dont know in the first place. They are 3 way vented bookshelf speakers which go down to 55 hz and are 6db down at 44 hz – but that doesnt tell me anything about the crossover slope does it?
Brad Paulsen
No it doesn’t. Maybe call the manufacturer and ask for customer service. I am sure they would know.
Brad Paulsen
No it doesn’t. Maybe call the manufacturer and ask for customer service. I am sure they would know.
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Soundminded
It seems to me that when considering the Bodie plot of a filter network which is all a crossover network is, there is substantial phase shift in the region where the amplitude response changes rapidly with frequency. The higher the order of magnitude of the filter the greater the change. Therefore two different drivers with very different phase angles will add in and out of phase causing extremely irregular amplitude response, the higher the order of the filter the worse the results. Also it is critical that the filters of adjacent sections be an exact match. If the drivers are in phase but corner frequencies overlap there will be a rise of up to 3 db. If they leave a gap there will be a region where there is little or no output at all. To prevent this, an active digital crossover network at the preamplifier signal level is likely the only way to assure this won’t happen. Ordinary production tolerances of analog networks, especially passive networks are likely just not good enough. It is to Peter Snell’s credit that he recognized this problem and made adjustments and repairs taking the variables in driver parameters into account when tuning each speaker system.
Gannon
Brad,
I just noticed your reply here…I am indeed the same fellow. I was in hifi retailing in Detroit from June 1981 until December of 1990, when I opened a custom installation firm after getting into trouble for spending too much time with my clients on the showfloor. Spent a decade forging that new market in Detroit and Chicago, helped greatly by the best manufacturer’s rep the industry ever had…Rob Ward. If not for him, I wouldn’t have taken that third-ever Imaging Science Foundation seminar…or been a B&K dealer. I think you and I were with John when he tried to leave the back of the convention center in Vegas with an amp for someone at the high-end hotel…and the entire union workforce coagulated into a human barricade to stop us. That was pretty freaky.
Then I got lucky with the Stereophile group, first by being the guy in the city with the tools to calibrate Lawrence B. Johnson’s sets…then through his suggestion, undoubtably, to then take Tom Norton’s place in the game of musical editor’s chairs. If only he didn’t need me to stay in LA, I might still be with them…but after 9/11 I had to leave. Switched over to the Absolute Sound group at just the wrong time…just prior to their editorial shakeup…and inadvertently toasted a few bridges along the way.
The last decade delivered an extended sabbatical, and while I’d LOVE to start a magazine critical of the industry…it looks like I’m going to put my energies into helping my Detroit musician friends capture their creativity instead. I’m still all about high fidelity, and realize that not many recording engineers have a concept of high-end tweaks! I seem to be the only one in Detroit who appreciates mixing and mastering in surround, even when the end product is merely stereo.
See you at CEDIA, if I get the gumption to be tortured again…if I don’t get to CO sooner. I’m overdue.
Cheers,
John