Sorry, does this belong in “tech talk?”
Is Speaker design evolution stagnant
Based on what I read from speaker manufacturers, many use the same drivers but apply different crossover philosophies to achieve a particular sound.
My simplistic understanding is that while limiting the range of high or low signals , the remaining signal is corrupted ( phase inversions, roll off, etc.. ).
With today’s technology, why aren’t more speaker manufacturers using active crossovers to be connected after the preamp and sending exact spectrum signals separately to be amplified to each driver. That would Eliminate all electronics inside the speaker cabinet except the drivers. Each driver gets fed only the signal that it works best at. No out of phase, half phase, quarter phase issues, no phase angle issues. 100% of the power goes to each driver without limiters to scale it back. I think Bryston Model T Actives is designed this way ( don’t work for them and not pushing any product). Am I looking at it too simply? Do electronic crossover play havoc on signals the way inductors and capacitors do?
Some speaker manufacturers have gone half way with built in woofer amps ( Vaughn?)
Of course you would need a 3 channel amp for each side ( based on W/M/T config) or some variable of mono amps, whatever.
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Well, I'd say a big reason is cost. Most systems are 3 way and you're talking about needing 3 stereo amps to do the job. Most folks don't want to spend even the cost of their speakers on amps. I doubt too many folks with $100,000 speakers have much more than $50,000 in amps behind them. Nobody is powering $100k speakers with $200k of amplifier. And that's basically what you'd be asking the customer to do. The other problem is that crossovers get a much worse rap than they probably deserve. Sure, they have failings, but all the snack people talk about them doesn't seem to materialize in measurements or listening given that the crossover is well thought out. Cost-no-object speakers like the Wilson Master Chronosonic don't even do away with crossovers, and that leads one to presume crossovers have underappreciate virtues that don't get much attention. |
Some manufactures and designers are using techniques like you describe. Linn has been using active (Aktiv) systems for decades. All of Meridian’s speakers/systems use digital active processing. Solutions such as MiniDSP allow people to implement digital active crossovers, time alignment, parametric equalization and room correction. Passive crossovers have become a mature technology and technique, and the amplifier watts to power them have become more affordable. Both passive and active designs can offer great sound, but more and more companies are starting to utilize active systems and digital processing, which I think will continue to grow in the future. |
Given the ever dropping cost of computer technology and ever increasing processing capabilities , this is what I imagine will happen IF there is good money to be made : a few companies will pop up to manufacture active crossovers that can be used with any speaker along with an application that can be operated from a computer ( I-pad, I-phone, laptop....) and utilize a Bluetooth microphone. It will allow you to generate the full spectrum of sound, take readings, give you graphs and allow you to equalize your speakers on the fly. i know some form of this exists, but I am talking user friendly software with real time results on a graph. like my son’s simple clip on guitar tuner, 3 led lights that light up to show you whether to tighten or loosen the string to be in tune. As as far as the cost, I think manufacturers will jump on board if they can sell more amps...home theater setups get people to buy 5-7-9 speakers instead of 2. that seemed to catch on. |
OP: You need to go away. Seriously. You need to go away from this forum and go build your own active speakers. :) Join us over in DIYAudio or the Parts Express forums. You'd learn a huge amount, build just what you like for pennies on the dollar and be much better informed than you'll gain from hanging out in open forums. Good luck, Erik |
Given the choice, many speaker manufacturers would probably say that a every speaker should be built with its own external crossover and dedicated amplifiers, optimized for each driver. Every parameter would be within the designer's control. But the audiophile marketplace just doesn't accept that whole integrated philosophy. People want to mix and match speakers, cables, amplifiers, etc. So speaker manufacturers build what they think people want to buy. |
I agree that active crossovers are excellent. Yes you need more amp channels. But multi-channel amps are readily available. Take Erik's advice and learn more about this. My suggestion is to check out Linkwitz Labs website. Linkwitz also eliminates the box. His speakers are stunning IMHO and you can build a pair! |
GT Audio Works produces their own planar drivers without any crossover on their main mid range panel which is about 6 feet tall. They have won numerous best of shows and unlike other planar magnetic drivers that have a plasticky sound due to the fact is a single membrane these particular speakers have a quasi membrane which is bonded to the mylar which causes no resonances. The technology goes on and on with the speakers such as a frame with in frame construction to reduce any vibration resonances, the use of pure copper traces versus the cheap and inferior aluminum which is not as good as an electrical conductor as copper. Another important fact is is that the speakers have a lifetime warranty and have a lifetime upgradability. These are also the only speakers that are being produced with cryogenically treated drivers |
I would not say development is stagnant, maybe just turning in a direction away from whats been done for years in one form or another to a new direction fueled by new materials and theories. Back in the infancy of speaker development, Kellog and Rice of Bell Labs patented a new speaker technology the electrostatic speaker, it used stretched pig intestines applied with gold leaf to hold a static charge as a diaphragm material, obviously it had its drawbacks !! Mylar, the diaphragm material needed to make this tech possible was still 18 years away. Same holds true today.new materials and applications will open up new possibilities. For instance, check out this video https://youtu.be/HGOt3JhrUs0 Graphene can be exited and caused to radiate sound by beams of light modulated by a music signal. Cool !! Greg |
There was also work with ultrasonic transducers which vibrate the air at frequencies the ear can hear with very directional properties. It could lead to music aimed at you like a parabolic dish which only you would hear, like headphones but nothing on your head. https://youtu.be/4eZVF1ouTT4 https://youtu.be/hmNzf9ztnAk Greg |
Erik, so tempting to build my own, but I have to admit......I’m afraid. So much to learn. Before I make a choice of any component, I may end up looking at all the alternatives to make sure I make the best choice. I am not afraid that everything on paper looks good but the actual audio result may stink. I can live with the journey and failure, just don’t know if I am up for the amount of learning work involved to understand theory and apply math. i really am not at the semi engineer level that many of you kind posters are. But I will look at the other forums and see if I can follow. jack |
Greg, fascinating technologies, Really fun stuff. Great practical applications. I think plasma speakers are pretty cool too. Faxer, in the 70’s I saw foam flat panel speakers. They sounded eh...ok at low volume. The beauty is , as you stated - single driver so no crossover. But if you pumped more power into them they would catch on fire. |
Jack, GR Research offers a number of speaker kits that are not too difficult for a 1st time DIYer. Check out the website. By the way, the OB/Dipole subs found in some of the GT Audio Works speakers (mentioned above by faxer) are actually a design/product made in a joint effort between Danny Richie of GR Research and Brian Ding of Rythmik Audio. Fantastic subs! |
One more time. Here is a link to Madisound for the Linkwitz LXmini speaker kit. There are online videos from folks who have built these. Active DSP crossover w/ Linkwitz design genius offer great, no, GREAT sound. Kit is about $530, You assemble and paint. Check it out. I have the early version and love them. https://www.madisoundspeakerstore.com/2-way-speaker-kits/lxmini-linkwitz-lab-speaker-kit-pair/#tab-3 |
All speakers are build practical the same :tweeter, mid- and bassspeaker. Now there is one exeption: the Ilumnia Magister, build by two brothers in Belgium. Those 2 boys worked for 7 years on it. It is the first speaker in the world with a floating Crone driver on a magnetic field. It’s 99,7% linear/always pure sound, regardless of noise level or dynamics. Theorie slogan is: Less is more. This patented and progressive loudspeakertechnology gives a new dimension to high fidelity. No energy absorption: 100% preservation of th signal down to the smallest details. No unwanted resonances and distortion caused by spider and driver. I have them at home,and i can say: I never heard such a pure and detailed sound. High-,Mid,and low in harmony. You can see them on the website: ilumnia.be. Now they are buiding a Monitorspeakers. |
A bit of history, if you don't mind: In the mid-1970's one could purchase a combo-effort on the part of two of the premier manufacturers. Magnepan's inventor Jim Winey and Audio Research's inventor Bill Johnson got together--whether Wendell had anything to do with it is moot--and developed a tri-amped system that used an external (tube) crossover. The Typmani speakers were in three parts...kind of what Mr. Winey's son has gone back to recently, with superb results...and they were driven by three+ (you could bridge the amps and run 6 if you wanted to) Audio Research amplifiers run through an Audio Research SP-3 pre-amp. The amps were of the D-76(A) vintage, which was then doubled into the D-150--still an awesome amp all these years later. The crossovers were both passive (PC) and active (EC-tube), and one could select a number of ways to set this up. More importantly, HOW DID IT SOUND?? All that technology is fine, but if it does not sound like a live concert, or as close as possible to one, then it is of little value. The good news is that the SOUNDED AWESOME. Set-up properly in a good room, this was the ultimate in those days. Today, I would guess that the new Magnepan 3-part speaker set driven by quality amps is probably somewhat better as the technologies of all these components has improved since the mid-1970's. In any case, it sounds better than any box speaker system, so I don't think speaker design is in the tank today. Most designers use conventional drivers, but I constantly see engineers trying different materials, etc., to get the accurate sound they are seeking. Too bad that Magnepan found a way to do it better than cone or electrostatic designers have so far...but that doesn't mean engineers are not hard at work looking for the "next big thing." |
Jack, There are many ways to get into it, but in my experience it has been very rewarding to go active and take the learning curve. I echo what Erik suggested about diyaudio (multi-way forum). I started my journey 4-5 years ago. I had a great preamp (Lamm LL2 deluxe) and loved it, but thought a system optimized to do one thing very well would be better, for a given amount spent, than a system attempting to do several sources as good as possible. I bought a multichannel DAC, took the Lamm out, built an "audiophile" computer to be my only front end, and implemented active crossovers between my subs and mains. The tube amp was happy not attempting to reproduce below 80Hz, and so were the B&W 804 speakers. Sound improved. Then I purchased "class-D" amp kits from Hypex, assembled, and now have those 400W driving each B&W bass section. So I removed the passive crossover and have the Hypex directly connected to the woofers, running from 70 to 350Hz. For now I still have my McIntosh tube amp driving the midrange and tweeter section, where the passive xo between them is still in place. So it's a 3-way active. In the process I learnt a lot in many aspects. I am now working on a pair of DIY 4-ways, fully active, to replace the B&W. I really love tubes, and DIY active allows to design to maximize the benefit. For example I want to use SET for the mid and treble sections and SETs are constant voltage sources so high and constant impedance speaker is a real benefit for them...so that narrows it down for me pretty good. I belive conditions have matured to go into this direction. Digital signal processing is enabling stuff unheard of some years ago. Low power Class A amps aren't very expensive these days (SETs or Nelson Pass' First Watt, for example), class D amps of high power and good enough performance for bass are cheap these days, professional speaker drivers are pretty good and a lot cheaper than exotic audiophile stuff (which I reckon I also like). A Rythimk subwoofer kit is cheap. You can build a 3 or 4-way system that will sound super. There is also a lot to be gained with good box (or lack of) design practices - things that tend to be too labor intensive for manufacturers to adopt). It's been a rewarding experience for me. The big trade off is the time I've spent, and will continue to spend. But that's part of the fun for me. |
Loudspeaker design evolution most certainly stagnated. Precious little has moved forward since Y2K. We've seen some improvement in drivers, but mostly in cabinetry, as that is where the talents of today's builders lie. Most of the reason is the designers who either understood the art and science or possessed the intellect toward that have left us. Look to the designs of the previous two generations, you find radically more innovation, and the work of these folks still shines |
If you effectuate the crossovers in an active speaker in the digital domain you can elimate the phase shift, ringing and asymmetry of analog crossovers, as well as temporally adjusting for the different path lengths of the various drivers. If it’s your cup ‘o tea you can also effectuate dsp room correction at the same time and there are many speakers on the market which do this. Seems to be the best answer to me. The only thing that holds me back is that my primary sources are made of vinyl and shellac and the old dog in me recoils from digitizing an analog signal. Just foolishness on my part. |
@kosst_amojan absolute no necessary spend huge amount the money if you use 3 way electronic crossover. You can use 2 amps for bass and midbass non expensive class D or class AB , but for mids and high absolutely necessary use high end amps, and basically is much more less money because you need the high end amps much more less power then use one high end amp for all 3 drivers ,like convention 3 way speakers with passive crossover design. Actually you can use 2 big power class D and one low power SAT tube amp. But is very hard and almost impossible made right balance . You have to use measuring microphone and computer program like RTA |
it Seems to me that the flexibility and cost saving to use class D amps for the woofer and AB amps for mid/tweeter is another positive reason speaker manufacturers should be evolving toward targeted amplification of drivers. so I guess the point Bache makes that once you do this you have to strike the righ balance - that is the weak link in the chain, or the hard part to achieve |
Jack, A significant point Bache made and I neglected to mention is the need for measurement. This means a mic and learning how to do it. USB mics are easier to implent but not as good as the internally do analog to digital conversion with a clock that is different from your DAC. But an easy way to get going, which in my mind is most important. Incremental improvements rather than radical changes. The learning curve for radical changes is even steeper than the upfront cost and likely to frustrate. |
@Jacksky Yes , i already know what i am talking about, i made semipowered LS Bache audio-002 with build in 2 amps . one for low base 25-150Hz (adjustable) and one classAB 100-700HZ (fixed) customer need just one external low power AMP. sound pressure was balanced (using RTA) sound so good , so need to be listen |
@bache I build or rebuilt my own stuff except for the Focal speakers. Practically nobody here is listening like I am for as little money as I've spent. To do as you suggest I would spend nearly the price of the speakers to simply build the crossovers and amps out of individual parts. To actually buy the amp I'm using retail you'd spend about 75% of the price of the speakers. You're talking about some VERY cheaply built amps of the sort I'm not even interested in looking at. Stuff like you'd see at Best Buy. What seems to go unnoticed here is that passive crossovers are artfully designed to compensate for the shortcomings of driver and cabinet behavior and you're not going to get that result with an active crossover unless it's carefully tailored to the speaker; a skill practically no DIY'er has, and most definitely a trait no retail unit will get you. If you're going to go the active crossover route, you need to be pretty sure your cabinet and driver alignments are dead on because a simple active crossover will give you none of the corrections you need to compensate for less than ideal cabinet and driver behavior. |
kssst_amojan, I dont want to argue. You are DIY guy and build and rebuild for own use, i hope you sound as perfect as you tell us. is no secret we use high quality amp module from Hypex , it not such expensive and no chip, we have account and get good price. you see on market now plenty accembled amps based on Hypex M-core Some people like it ,some not, but without doubt is best choice to amplified 25-700 hz, The quality , damping is excellent amd price for all parts no more $700-800 per speakers ( no labor cost) FOR mids and high my customers using low power class A (tub or solid state) My personal preference is Pathos double TT 20 Watt per channel. See my http://bacheaudio.com/bache-audio-002ab-loudspeakers-v2-stereotimes-com/ http://bacheaudio.com/6moons-audioreviews-bache-audio-002ab/ |
@bache Not trying to argue. Just pointing out facts. Generally, the more complicated you make the system, the more complicated the problems and distortion get. I've seen what it takes to make an active crossover that replicates what a well designed passive can do and it's a fairly monumental task with debatable benefits. The question is why more people don't do what you suggest and that's the answer. It's extremely complicated and the results aren't really worth the hassle. |
Kosst, What you describe is true, sometimes. As usual it depends on implementation. Active digital xo aren't that complicated to implement and can solve the issues you describe if done right. At a fraction if the cost of passive. But the system has to be designed to work that way - not just the xo. Why this isn't used more frequently? The learning curve is steep. It's a lot more involved. You need to be able to measure. It's a lot simpler to connect an amp with a pair of wires to the speaker, play music and call it a day. |
