17 of 23 speakers in my studio and home theater systems are internally powered. My studio system is all Genelec and sounds very accurate. I know the best new concert and studio speakers are internally powered there are great technical reasons to design a speaker and an amp synergistically, this concept is much more important to sound quality than the vibration systems we often buy. How can an audiophile justify a vibration system of any sort with this in mind.
Full support of commercial anything beyond 10 years is rare. So you have the ability to fully support, today, a product that is 20 years old. Based on failure rate predictions and field failure rate data there is an appropriate stock of fully assembled amplifier boards and/or individual parts in a warehouse for a 20 year old product. That is a sunk cost the Finance department approved for every product and baked into the cost of every product sold?
Or could support consist of a limited supply of custom items backed by purchase as needed resistors, transistors, caps, op-amps etc.? That seems like an approach the Finance department would support.
@thespeakerdudeWow, I listened to Bruno’s talk about the Kii, He is making a speaker just like a microphone, I’ve had this idea for 30 years. The way directional microphones work is there is vents along 2 opposite side and when the sound comes in from the front the sound also comes in from the opposite sides but out of phase thus canceling out except the sound that comes from the front of the mic, the more directional the microphone the more vents there are. Rruno is doing the same thing in reverse electronically in the Kii. Condenser microphones are "active" dynamic microphones are "passive" interestingly enough the "active microphones" are of course better in practically every way but they need power (Phantom, usually 48v). Also all the audiophiles that understand this analogy are probably all using "passive" systems that we know in reverse ie. microphones are not nearly as good in sound reproduction.
One can easily see that this support model is very different for large public companies with strict product plans and clear cut departments that operate the business vs small engineer owned private companies that pursue new ideas and build what might look risky to the large corporation.
The different responses in this thread make sense with different scales of business. What amazes me is the level of intelligence expressed in this thread - starting all the way back to a baseline of Kenjit all the way to engineers and operators of consumer audio businesses. An excellent discussion overall that should help users understand that engineering and science drive most audio innovation and the day of the freewheeling entrepreneur who just experiments in his garage are over. Bullshit may still sell but not for long.
@donavabdearthe Dutch and Dutch 8C is just like the microphone with vents and all (and some DSP), the Kii (Bruno) does it with electronics. Sky is the limit.
@thespeakerdudeI'm amazed I've never told anyone about that idea but Bruno did it, so neat. There are problems with interference tube designs, there are spurs in the rear polar patterns that are very hard to tame. Also off axis coloration is worse when the directionality is longest.
I also had designs of an optical digital laser microphone that could listen from miles away. Hope no one figures out that one.
I also had designs of an optical digital laser microphone that could listen from miles away. Hope no one figures out that one.
I hate to break your bubble on this one. Those have been around since the 80's probably earlier. I don't know if they were initially designed as a surveillance tool, but that was one application. They can pick up the vibrations on window glass. Now they are a common industrial tool as well.
donavabdear, do any of your Genelec speakers have the dynamic correctness and dynamic excitement and immediacy of a large properly designed fully horn loaded system with horn bass in the low 20s Hz range, DSP crossed over, speaker corrected, room corrected, phase and time corrected speaker system?
We know the answer to the part of your post prior to “DSP crossed over …” That is, they remain unresponsive here because they’d have to give us an admission, but if pressed they will likely counter thar the traits pointed out by you on all-horns are unfit for domestic environments. To many an MFR it seems even their weaknesses have to be sold off as the opposite.
I won't speak for @donavabdear, but I will speak for myself that the question is essentially irrelevant and is begging an answer. Phase corrected is essential for any working speaker design, time corrected looks much better on a marketing sheet than providing verifiable listener benefits. And yes, I have personally done the testing. Dynamic correctness, dynamic excitement seem to be implying the same thing. How long can you play, and what effects of any concerning dynamic compression. Horn loading / compression drivers is not the only way to achieve this of course. Horns provide, properly designed, constant directivity, but using a standard woofer/mif-woofer and a wave guide tweeter provides similar benefits without the side effects of vertical directivity lobing which can cause unpleasant reflections off vertical surfaces, likely one of the reasons why some people "don't like horns". I think we can agree that a real horn loaded speaker at 20Hz, even a tapped horn is rather enormous and outside the realistic realm for most people. To achieve true directivity at the frequency is just unrealistic and you are not going to avoid room modes. Velocity/position feedback eliminates power compression issues in subs, and cheap efficient amplification is plentiful. Just put in a bunch of power subs and be done with it.
@donavabdearalready wrote he only has one sub for his Genelec system (maybe in a different thread, I lost track). @donavabdear, I have to expect that is contributing to some of the difference. I would consider playing around with integrating your main subs the the Gens even as an experiment. That or play with the single sub near-field. Not sure why this came to mind, but someone asked what the best sound they could get for a $1000 was. I told them $500 headphones and near field sub for the emotional impact.
@thespeakerdudeintegrating the subs, that's a good idea, it would be very easy. I'll let you know. Also your advise about the headphones is spot on, exactly right.
@kingharoldSorry it's been a while since I have listened to horns with respect to accuracy. Time alignment is working ok not great, I have to move the speakers physically to get everything right. DSP seems like a fix but not really. The front speakers are time aligned and they are imaging like I've never heard before the point source nature of the speakers is different than the Tannoy or Uri or older Genelec speakers I've heard in the past I very much disliked those older speakers but these new Genelecs are really different, they worked out imaging, transients, and dynamics to a much greater degree. As far as dynamic correctness, hard to answer that i don't think there is any speaker that can reproduce thunder or a real symphony because no microphone can record it, even our ears don't treat dynamics as opposed to transients in the same way. Probably dynamics will be the last sound variable figured out in sound playback because there is nothing that records the loudest sounds properly. I used the very best recorders and microphones available to record production sound on movies and TV I've recorded 100s of thousands of gunshots but none of the recordings sounded like the real thing. On the movie Pearl Harbor we used the real 50 caliber guns these guns were mounted on steal surfaces the ships they were so loud the camera operators had a hard time physically moving their bodies because of the sound pressure waves the guns created. Real dynamics, impossible.
That or play with the single sub near-field. Not sure why this came to mind, but someone asked what the best sound they could get for a $1000 was. I told them $500 headphones and near field sub for the emotional impact.
@thespeakerdude on a side note can you please explain or send me to an article explaining why WMTMW drivers on speakers work at all concerning phasing? Especially the midrange drivers being 1 foot apart is seems to be silly. I'm sure it's something I'm simply not seeing I know many very expensive speakers use this system I just don't know why. Thanks. BTW I've never seen one of these speaker at a high end studio. I think after these Genelecs continue to cause big changes in speaker design you won't see WMTMW designs anymore.
MTM of WMTMW are meant to be listened to on-axis at tweeter height or whatever the tweeter height is based on the total speaker angle. At that height, there will be no phasing issues (assuming I know what you mean). The sound from the two mids-woofers at all frequencies will get to the listener at the same time. The crossover is designed as such that those frequencies all arrive at that same time. This has an advantage over a flat-front MT where the ideal response is not perpendicular to the face but typically tilted down. That can be fixed by tilting the speaker up, setting the tweeter back, or electronically. It can also be fixed with a coaxial driver. I think that is the real advantage of a coaxial driver, consistent dispersion.
The problem with MTM is the vertical directivity is narrow making the listening height more critical. I have not given a lot of though, but the wide spaced woofers in a WMTMW should provide some line source effect and reduce the floor/ceiling mode which is good as those are usually the least treated.
I personally am not a big fan of MTM, and they really are not in favor. We know enough that they do not make much sense any more. Audio Science Review probably inadvertently has given Genelec a lot of press in the consumer market. They have released a great product obviously, but that does not mean other great products not as visibile with similar design goals don't exist. As they are now going after the consumer market, it may influence that segment of the market more than anywhere. The WMTMW is an "audiophile" thing. It does not have to make sense.
@thespeakerdudeYou did educate me previously, and it is brilliant saying "as an audiophile thing it doesn't have to make sense". I know microphones and when there is poor off axis coloration the on axis doesn't sound as good because you are listening to the entire polar pattern off axis and all. Having your head in a vice is cool but no fun some of the most meaningful moments in sound are when you can share your emotional journey with your wife or someone like that who has let you spend so much money on this emotional hobby. MTM off axis doesn't work and the stereo image has at least 4 drivers trying to make you hear a 2 foot to 2 inch wave there is no way to get really good imaging with a non point source speaker, I feel like I'm really missing something still, the advantages are few and the disadvantages are huge, same goes with line array speakers. The blending of waves from midrange line array speakers is by definition a phase problem. Sometimes I feel like there is so much BS in the audiophile world.
I feel like there is so much BS in the audiophile world.
To me the king of BS are measurements. I can understand BS in marketing, it is supposed to be pitched that way. Nobody ever says we are the second best company in audio. But publishing SINAD below the level of human hearing and then giving it a trophy? THAT is some BS. Then you have the variables, how was it measured and where and with what and by who. Then because you actually measured something now you gift wrap it in science which means BS is wrapped in more BS.
The BS meter was on tilt so badly AES had to draft new standards to replace the old BS:
I don’t expect AES-75 to have much or really any impact or influence on the audiophile community. It would be inaccurate to say it is targeted at the professional market only, but that will be one area where it will be used. It will also be a useful tool for professional users, i.e. engineers working on vehicle sound systems to provide a more useful and consistent measurement of how loud a system will go. It will no doubt show up in data sheets for some consumer products, and suppliers of test equipment will add it to their test suite but for the average consumer it will go unnoticed.
On measurements in general, given that many audiophiles don’t trust the science currently, including, importantly, what the limits are of the audibility of distortion, than measuring or rewarding performance below or far below scientifically validated limits is not unwarranted.
The BS that AES75 recognizes and attempts to address is that you need verifiable standards, not some whack job with a volt meter measuring stuff in his thread bare living room:
" AES75 is designed to be independently verifiable, using analyzers and microphones typically used by audio professionals. By being independently verifiable, AES75 provides system specifiers and users a much more enforceable metric to use in quotes and architectural specs.”
On come on @kota1, you should be ashamed to even provide that first link to superbestaudiofriends. That is nothing but someone upset that someone is pointing out that their high priced equipment probably does not do what they say it does. I don't know Amir, but looking at this photos and background, he does not appear to be hurting for money. To suggest he is on the take from some Chinese vendors, or to link to such an article, without any proof at all, is morally corrupt. Attacking the messenger because some companies are able to sell low cost products that perform very well? When has attacking the messenger been anything other than a deflection? Do you want me to go through that whole SBAF mess? Free gear? I saw his system. Hardly seems to need free relatively inexpensive gear. Amplifiers and DACs with inaudible distortion being rated poor? I already covered that. There was a comment about a MOTU being incorrectly compared using single-ended versus balanced. Looked at the review. That is incorrect. Balanced was used and even used at higher output than standard as the result was better.
I will take on one specific topping in that attempted hatchet job because it applies to this topic and that is specifically the comments made about his review of the SVS Ultra Bookshelf versus the JBL305 (at which time he compares the JBL control 1). Now the point the author seemed to be making is special treatment of JBL. As a first point, he effectively said the JBL Control 1 is really awful. Hardly special treatment. He did say he liked the JBL 305 a lot, but not the SVS Ultra. As noted, his listening area appears to be untreated. He listens single speaker, not sure if near field or not. Let's dissect the dissection that the person incensed with audio science. He makes a claim about the calculated in room response being pretty good, and said Amir's comments didn't match the graph. Amir's comments were warmth or brightness depending on how your draw the line. That is exaclty correctly. The calculated is just that, calculated based on a "typical". Depending on your room, it may be bright or warm. The incensed also took issue that the JBL room response was not as smooth as the SVS, and felt this could be corrected.
Perhaps the biggest issue with Audio Science is that it presents highly technical measurements that are then interpreted incorrectly by people who don't understand them. You can't make conclusions about a speaker by looking at one graph. The SVS has several glaring issues. It has some dips in the on-axis response. These will be audible. Worse, it has a serious off-axis response at 3KHz and at 7Khz with varying issue in between. Right there, you have broken 2 generally fundamental aspects of designing a good speaker by modern standards. What that means if you attempt to correct the room response as the SBAF person suggested, you would wreck the on axis response even more causing worse issues, not fixing them. There is also some additional directivity issues from 2-3KHz you don't want in a modern design, and the cabinet resonances seem high. The JBL305 is not perfect, but the on axis response has not broad irregularities. The ones that are there are narrow, so far less audible, but not so narrow they look like resonances except around 1.7Khz but that could be crossover overlap (Amir notes are resonance). Off-axis is very smooth and simple a sloped shift from on-axis. That is very important as it means you can correct the room response fairly well without breaking the on-axis response. The 305 does not appear to have any directivity discontinuities. When you look at the totality of the measurements, and you understand what they mean and how they interrelate, then it is not at all surprising that Amir did not like the sound and that he could not EQ it to fix the issues. He did comment it played loud without distortion by the way.
I can only assume @kota1, that by whack job you mean Amir at audio science? Do you feel you are in a position of knowledge or experience to make that conclusion.
The BS that AES75 recognizes and attempts to address is that you need verifiable standards, not some whack job with a volt meter measuring stuff in his thread bare living room:
It did not take long to figure out that audio science is using a Klippel for speaker measurements. This is hardly a volt meter, and represents the state of the art in audio measurement. I think he runs it in his garage, but it almost does not matter as long as you have enough space. The point of the Klippel is that it does not need an anechoic space or treated room to measure accurately. It is a great tool, though a bit slow as a development tool. The Klippel will export a CEA2034 compliant test report. That is a far more extensive test standard than AES75. The reports that audio science publishes are from within the CEA2034 measurement set and appear to cover most of it. CEA2034 would also be considered "independently verifiable", as it sets out the full test standard, methods of test, equipment requirements, reporting, etc.
CEA2034: Standard Method of Measurement for In-Home Loudspeakers
This standard describes how to determine the frequency response, directivity and maximum output capability of a residential loudspeaker. It is intended to determine the audio performance of a loudspeaker, not the loudspeaker’s ability to survive a given input signal. This standard applies only to loudspeaker systems, and not to raw transducers.
This contrasts with the AES75 standard, which has one, and only one function,
Abstract: This standard details a procedure for measuring maximum linear sound levels of a loudspeaker system or driver using a test signal called M-Noise.
I don’t consider his apparently very high end electrical test gear "a volt meter" either and fail to see how his thread bare living room will make any difference on the measurements. From my colleagues, apparently the standards around electrical performance tests are not extensive and all over the place. They also say it does not matter much as long as the fundamentals of the test is communicated. The speaker testing is well beyond anything anyone else has done previously in online reviews. I don’t know all the ins and out of the electrical testing, but even if there are flaws, it still appears far more detailed than what has been done previously.
I will comment that listening is not done as per AES20, but no audio reviewer comes even close. AES20 requires a stereo pair, but it also places requirements on the room and placement, as well as the requirement for blind testing. Without an optimized conforming listening room, single speaker listening will provide the most repeatable results which appears to be done.
@kota1, I am not sure what that link to the other thread here on audio science review is supposed to prove? A quick skim from the end and working back and I could not find any good examples of where anyone provided a solid founded argument to support what you claim. Looking from the outside in, I saw a lot of emotion driven writing, but little in the way of fact driven, logical arguments with supporting documentation. Some of the people responding should be giving their "adult" cards back.
Giving myself a reality check, I am not sure what any of this has to do with powered speakers. I feel like the new AES75 standard was just used as an excuse.
I refer you to the other threads here to discuss that other website, @donavabdearmentioned audio BS so I chimed in.
As for a "reality check" I am still waiting for you to post your system, your measurements, etc. So, reality check time, mine are posted in the virtual system area, still waiting on yours.
If you posting your system's pictures is supposed to lend any credence to what you say, I am sorry to say that for me, it does not sway me one way or the other. Like musicians often having crappy sound systems, I know some excellent people involved in speaker design who have relatively modest systems. Personal and professional passions don't always align. However, if you know speakers, it would take about 2 minutes of talking to them to know they know their stuff. Hence I place more value in what people say and know.
I will give you an example. You post pictures of near flat room corrected responses in your system pages using Audyssey apparently. Critical is your front left and right. I assume, based on some things you wrote that you think this is a really good thing. If you know the limitations of the Audyssey correction system (and Arc) you know this is not a good thing. That flat of a room response given the pre-corrected response means that other aspects of the response that are also critical were compromised. That is why advanced systems like Lynggdorf and Trinnov have both better measurement (out of necessity to work properly), and more flexibility on correction. Dirac is somewhere in the middle, though I am looking forward to how Dirac Active performs in the wild, not to mention the expected patent battles.
Dolby Atmos and active speakers are the future. The AES should set up a foundation to start from as far as speaker setup and acoustic response to keep mixing consistent. 12 speakers are hundreds of times more complicated than stereo. The AES should leave room for creativity and they should get together with SMPTE to at least pick the channel that the Sub and center Chanels should take.
In a thread on active speakers kota1 shares he is an advocate of active speakers, uses active speakers, and posts his system and pics of active speakers.
@thespeakerdude, who has nothing posted about his system is not impressed.
As far as dynamic correctness, hard to answer that i don’t think there is any speaker that can reproduce thunder or a real symphony because no microphone can record it, even our ears don’t treat dynamics as opposed to transients in the same way. [...] Real dynamics, impossible.
By that token every aspect of sound reproduction, as something that aspires to a live acoustic or even amplified event, could be shrugged off as "impossible," and yet here we are with each our priorities and you and @thespeakerdudeconveniently sidestepping dynamics because it’s a bad business model working from an uninhibited size factor.
It’s damn semantics; if by "dynamic correctness" you hold that achieving such is impossible in reproduced form, you fail to realize that some speaker implementations are way more dynamically capable than others, to a degree that makes a very worthwhile difference - even without meeting the "real thing." How about emulating the Apollo missions’ Saturn V lift-offs (from safety distance) in your home - good luck indeed - but those Genelec’s and other small toy monitors would crack open trying, while other more efficient, properly sized horn-loaded/horn hybrid iterations would actually give you a sensation of what it would’ve felt like. Just as an example.
Going after more lifelike dynamics is absolutely worth it for those who aren’t restricted by size demands or otherwise simply wills it as a factor to pursue. The consumer can actually go with whatever speaker scenario one chooses, and accommodate accordingly.
Dynamic correctness, dynamic excitement seem to be implying the same thing. How long can you play, and what effects of any concerning dynamic compression. Horn loading / compression drivers is not the only way to achieve this of course. Horns provide, properly designed, constant directivity, but using a standard woofer/mif-woofer and a wave guide tweeter provides similar benefits without the side effects of vertical directivity lobing which can cause unpleasant reflections off vertical surfaces, likely one of the reasons why some people "don’t like horns".
"Vertical directivity lobing" isn’t an argument against proper horn-loaded compression driver-fitted speakers that wouldn’t potentially befit a low eff. waveguide + tweeter solution. Dynamically however a standard, low eff. woofer/mids + dome tweeter on a waveguide certainly falls short by a mile compared to a high eff. pro woofer/mid and compression driver + horn combo - it’s no comparison, really, also as something that matters and is perceivable in a domestic setting.
I think we can agree that a real horn loaded speaker at 20Hz, even a tapped horn is rather enormous and outside the realistic realm for most people. To achieve true directivity at the frequency is just unrealistic and you are not going to avoid room modes. Velocity/position feedback eliminates power compression issues in subs, and cheap efficient amplification is plentiful. Just put in a bunch of power subs and be done with it.
We can agree re: size factor of horn-loaded subs @20Hz, yes, but that’s not to say it isn’t doable if one so chooses. 20cf. per cab is sizeable, but once tucked away in corners they actually stay there.
What you don’t do, categorically, is bend the laws of physics with small sub size wanting to maintain extension, but in multiples they can ameliorate some of the weaknesses here. You work from a limitedly sized physical package, I and others around here don’t, and don’t tell it doesn’t matter. You know it does (and if you don’t you haven’t heard the difference or just don’t care), but as a MFR you try and downplay the significance as it suits your case.
And to be clear: you don’t eliminate power compression as proposed. There’s only one way around that, and that should be clear by now.
@kota1the topic of the thread is "Powered speakers show audiophiles are confused", not does @thespeakerdudehave a nice system. I have talked extensively about the technical details and underpinnings of active speakers. I can and do that all day off the top of my head. Have you posted anything relevant in regards to active speakers, how they work, why they can do what they do, why they will only get better, what technology underpins those advancement? No you have not. So how about you stick to the topic, and stop trying to make yourself look better at my expense.
Have you been following what I said I do? Speakers for professional applications? Do you think that just means studio speakers? @donavabdearmixes for movies where you are trying to "recreate" real dynamic events.
20CuFt is not really enough for a proper horn loading at 20Hz.
Tell me @phusis, what is your personal definition of "dynamics"?
What is a sufficient peak db level?
What is a peak db level listening to an orchestra say 10 rows from the stage?
How often are you trying to recreate a Saturn V launch?
@kota1oh man that is a fun room. I would give a lot to hear it. Interesting to hear music played at a low volume in a room like that I have a feeling it would poor, firehouse filling a tea cup kinda story. Impossible to mix for a room like that. Makes me think of seeing a dragster driving down Main Street looks cool but everything else about the drive may be a compromise. A lot to think about. Thanks
@kota1 Maybe you can help me here about a question from the amazing sound system in the YouTube video. Wave guide high frequency, in my day was popular until they realized that near field deflection is another word for phase problems, how can such a high end room use a proven physics problem? Wave guide mid frequency speakers in that room are guilty of the same sin. A bass speaker like the one in the video make so much more sense than a huge horn that must deflect the wave at some point in the horn. Is near field reflections / deflections not a thing anymore?
There are home theater guys that do custom builds with the type of horn speakers they have in movie theaters and multiple monster subs of the type @phusisdescribes. The goal is not to "hear" it but to get kicked in the chest with SPL’s when watching or listening at reference levels. In terms of reflections/deflections I am not familiar with the Trinnov optimizer. When the guy was reviewing the Dante related gear in the rack a lot of it was DSP related. The Trinnov guy said how his team had to create a new set of filters to optimize the bass in that room as even the microphones needed had to be customized because they could not handle that level of bass. The room treatments are hidden behind the acoustically transparent covering on the walls.
When they talked about playing the Metallica concert at 120DB with no distortion I had to smile. I have that same disc in my collection in both versions, including the 3D. I can’t imagine 120DB levels for that entire show. But now that I saw that sub I have already started planning on getting two more to bring my system up to four. This is from a review of my Sunfire sub:
But the main thing - the manufacturer claims that at such a scale that kid on the coveted 20 Hz provides a sound pressure level of 110 dB, which looks absolutely fantastic. Surprising as indicators and power - 2.7 kW (!) output peak and 600 watts continuous power consumption of the network.
If I can get up to 110DB in my much smaller room it will be good enough for me.
I use the same approach they used for the front channels, mirroring the front 3 channels above and below the screen (they used 5 instead of 3 because of the width of the screen). Having a top center channel just locks dialog in the center of the screen during a movie and anchors music mixes/upmixes as well.
@kota1@thespeakerdude
When anything is put in front of a speaker the wave is deflected somehow, when you put something like window louvers or a horn to guide high frequencies the wave is deflected. Many have mentioned "wave guides" and acoustic lenses focusing the sound, well I thought that was a fad 30 years ago because of course waves interact poorly when they are changed and mingled. I understand the kind of filter some speakers put over drivers that look like a grill to break up the waves in a particular way but focusing the wave is never a good thing, we called it near field reflections back when all those speakers were tossed away. Are they back? Has someone discovered how to make waves interact and keep the amplitudes in tact after the focusing? Even the grill on my own 9hs has a high tech symmetrical design to defocus the beryllium tweeters and midrange from sounding to harsh that is done on purpose to smooth (distort) the high frequency I understand that but if the acoustic lens is a guide that focuses the wave there aren't there inevitable problems.
I always think of microphones when I think of speakers, once I was doing sound for a concert with Wynton Marsalis, I was a big fan and very excited to work with him. He told me to put a Sennheiser 421(a large diaphragm dynamic mic) down stage and that's all he said his trio would play into it, they would mix themselves as they got closer and farther from the microphone. Just like Edison did on the first recordings ever. Well as you probably guessed the sound was great. The sound was so good it left an indelible impression about how important phasing was I never forgot.
Also
Dante is simply a network protocol that is used to send sound through a network cable it great for switching, There is no sound degradation and can connect to anything through Dante Control and Dante Via. Dante is the future.
The one wave guide I have personal experience that clearly stands up and salutes is the one JBL developed for the M2. After that development they started trickling it down to their other speakers. I think it is amazing and here is Frank Filipetti breaking it down (1:15). If you check out Frank’s discography and sample his mixes the "proof" is in the result IMO:
For you Genelec, the mid is the waveguide for the tweeter and the front is the waveguide for the mid, so we better hope things have gotten better.
Reflections, higher order modes, throat and mouth and edge diffraction, resonances, it is not as easy as it seems.
The answer is the problem still exists, but we have gotten much better at making them, not the least because we have software now (even in the DIY community) that really helps to automate and optimize aspects of the designs so instead of making a 100 revisions or more CNCing plastic, you are now making 5-10 and printing them. How many you need usually comes down to how good your model is of the underlying driver.
Our software like our competitors is a mix of proprietary software and off the shelf generic tools and plug-ins. Obviously can't post that, but I can post stuff out in the "community" that is really good. This reminded me of a interview with Earl Geddes, always as crotchety as ever, but also always interesting. I like the guy, don't get me wrong, but he is like that friend you have that is always cranky :-)
The video is rather apropos, as he mentions active and passive speakers too, though I consider some of this comments outdated. Some however, are not. The most important one is that active speaker design does not magically solve all issues. You need to start first by being a good "passive" or in essence fundamental speaker designer.
More relevant to the discussion is his mention of what he considers, and many agree, of the importance of constant directivity to ensure a speaker sounds good in most environments. This is a implementation embodiment of the Toole\Harman research showing smooth off-axis response is important. That does not solve the waveguide issue, it just give credence to why it is important to solve it. Very relevant to the discussion is the use of software for wave guide design. Geddes says that even the DIY S/W, or at least semi open source, does a better job than he was able to do. The software and a comprehensive discussion happened here:
@thespeakerdudeGreat, thank you for that. What is a problem is longer wave guides or horns or anything that is trying to direct the wave. Call 1k a 1 foot long wave (close enough) 2k is 6 inches 4k is 3, at this point horns and curved boxes with computer curves easily confuse the wave by bouncing them in and around whatever kind of guide the designer has made, there is no way out of that sinareo. Horns are never ok, they may sound good but the huge difference in size of waves doesn’t allow a horn to accommodate multiple frequencies properly. A traditional cone driver is simply a piston that creates the wave but doesn’t redirect it, (except for the edges and things like that) as horns do. My Genelecs use the term wave guide but it’s really wave takeoff more than anything because the size of the waves and the depth of the high frequency and mid frequency voice coil throw is so much shorter, they aren’t designed to guide the frequencies like the Tannoy and the Uri’s of the past which sounded like everything was pumped through a bullhorn, even a multi million dollar showcases theater with an 80 inch sub has got this wrong IMO. The 80 inch driver is a perfect example, what would that horn have to look like well it’s impossible to make a horn that accommodates frequencies that large between 1 and 20Hz you would need 20 huge horns. In that video they described midrange center channels that used a curve to redirect the waves to the audience, this is a big compromise in a no compromise room. A great Director of photography I worked in the movies always spoke of the light he used as "them" he would always bounce, diffuse, cut and all the other things DPs do with light by thinking of light as little particles that bounces around, so I told him use one of my sound diffusers to bounce his light it only makes sense, he was amazed he hadn’t ever seen that before. The moral of the story is if you think of the sound as particles that interact with each other you would never expect to send them down a horn and expect to not have them interact. Hope that’s a tiny bit clear.
speaker dude wrote, "I won't speak for @donavabdear, but I will speak for myself that the question is essentially irrelevant and is begging an answer. Phase corrected is essential for any working speaker design, time corrected looks much better on a marketing sheet than providing verifiable listener benefits. And yes, I have personally done the testing. Dynamic correctness, dynamic excitement seem to be implying the same thing. How long can you play, and what effects of any concerning dynamic compression. Horn loading / compression drivers is not the only way to achieve this of course. Horns provide, properly designed, constant directivity, but using a standard woofer/mif-woofer and a wave guide tweeter provides similar benefits without the side effects of vertical directivity lobing which can cause unpleasant reflections off vertical surfaces, likely one of the reasons why some people "don't like horns". I think we can agree that a real horn loaded speaker at 20Hz, even a tapped horn is rather enormous and outside the realistic realm for most people. To achieve true directivity at the frequency is just unrealistic and you are not going to avoid room modes. Velocity/position feedback eliminates power compression issues in subs, and cheap efficient amplification is plentiful. Just put in a bunch of power subs and be done with it."
I respectfully beg to differ. My DIY speaker system uses Bill Fitzmaurice designed HT Tuba 25 Hz quarter wave folded corner horns. The output at 25 HZ in my DEQX equalized system is identical to the output at the 1 kHz reference tone. The output at 20 HZ is still audible and musically useful. They are 18 cubic feet each but wearing a nice coat of Blonde Burmese teak veneer with solid teak and brass trim and tucked away in the corners where they need to be they don't seem particularly obtrusive to me.
Including the horn path in the bass bin plus the distance out to the midrange horn which is well out into the room where it can image better makes the separation between the acoustic centers and the woofer and the AER BD3 midrange drivers over 16 feet. The time correction provided by the DEQX DSP makes the acoustic centers of those drivers sound as though they are within 3 mm (less than 1/8 inch) of each other. That is not in any way irrelevant. If you have ever heard properly executed horn deep bass I think you would understand the difference between that and using a bunch of power subs and perhaps even learn what I mean by dynamic excitement. I notice that Genelecs best subwoofer is already 6 dB down at 27 HZ.
My system is active using six channels of amplification. Contrary to donavabdears contention that audiophiles who don't use a bunch of little active cones and domes in a box are confused I respectfully beg to differ with him also.
They are 18 cubic feet each but wearing a nice coat of Blonde Burmese teak veneer with solid teak and brass trim and tucked away in the corners where they need to be they don’t seem particularly obtrusive to me.
Thanks for posting this, the pics you posted are stunning. Some of the wannabes in this thread are keyboard warriors who are simply posers. Your handle is certainly appropriate from what I see in your system profile, nice job.
I would like to know more about the deep horn loaded bass you describe. What type of space do you need, budget, etc. Thanks.
Have you been following what I said I do? Speakers for professional applications? Do you think that just means studio speakers? @donavabdear mixes for movies where you are trying to "recreate" real dynamic events.
And your point is? @donavabdear made no effort to limit his views on dynamics to a given application of reproduction, but rather made a broad statement. I replied accordingly. To most here it’s about home audio reproduction. Dynamics should apply as one sees fit, however setting the bar high here isn’t some fad but rather acting on a hugely important aspect of music (and movie) reproduction. That it isn’t a higher priority has more to do with spousal demands and interior decoration (and even vanity) than a conscious "no thanks."
20CuFt is not really enough for a proper horn loading at 20Hz.
You wrote ".. a real horn loaded speaker at 20Hz," and I’m telling you a 20cf. quarter wave tapped horn with a tune a ~22Hz will do honest and proper 20Hz - period. What isn’t proper is asking a smaller size, lower eff. direct radiator doing the same, even with a surplus of power. And horn sub iterations can be in multiples as well.
Tell me @phusis, what is your personal definition of "dynamics"?
Let me put it this way: my take on dynamics is they matter more than many if not most audiophiles care to pursue via their home setup. Which brings me to your next question..
What is a sufficient peak db level?
To me "sufficient" peak dB level is a max. required SPL number with some +20dB’s of added headroom. A pair of corner placed (i.e.: with boundary gain) high eff. tapped horn subs and high eff. pro cinema main speakers with a combined 2.3kW actively per channel can shell out +125dB’s at the LP (~11ft. listening distance), full-range, so backwards math gives an easy 105dB’s with +20dB’s of headroom - within my actual required range.
Please note that I don’t blast my ears with +110dB peaks like a daily meal, if rarely at all. However, an abundance of full-range headroom provides wholly effortless, low distortion playback that few get to experience, even at levels that are downright physical in nature. The clean (and full-range) dynamic bandwidth not least comes in handy with Blu-ray/4K UHD playback of movies.
I could go on about describing this, but it really requires of one to experience it first-hand to know it. Suffice to say that when you have a bunch of high eff., large diameter transducers (or force multiplied via acoustic transformation) that move very little, yet while producing tremendous SPL’s at the LP, it can provide a very relaxed, full and immersive feel of sound that’s simply not attainable from smaller, low eff. speaker packages.
Coming down to it it’s really about the benchmark I’ve set out to go by within a range of core parameters, and has come to achieve in some measure. ’Core parameters’ may not apply similarly to all, and a MFR rarely has the luxury to go all-out in regards to core physics of reproduction, for reasons already outlined by you. Fortunately DIY and an open approach to which segment of gear is used can change that, relatively uninhibited.
What is a peak db level listening to an orchestra say 10 rows from the stage?
10th row with a large symphony orchestra during tutties? I’d say 105-110dB’s.
How often are you trying to recreate a Saturn V launch?
I don’t, really, and you obviously missed my point. Another example, here from the world of cars, and to hopefully get through with my point this time around: if, say, a Formula car is your effective out-of-reach reference, then for sure a Porsche 911 Carrera GTS is still faster than a Citroen Berlingo, and who among fast-car aficionados wouldn’t appreciate that difference in performance - even without achieving the speed of an F1 racer? Moreover, you’d certainly get a closer feel of what it means driving F1.
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