Distortion is not necessarily a significant factor.
http://www.gedlee.com/Papers/Distortion_AES_I.pdf
http://www.gedlee.com/Papers/Distortion_AES_II.pdf
Depending on the needs of the app it could be a wise decision if for example you didn't need to use it over the wide BW it's designed for, ditto my Altec 515B and similar, i.e. 'horses for courses'. 😉
Kippel?
But even without laser interferometry, science tells that the things in the world aren't solid as we think, say: electrons flow because of the weak orbital strength in metals...
Well...The Heil for me is not a good driver for 1.5 k hz whatever say some or the datasheet....1.8 k hz mini and eveb better above 4k.
Good luck to find an ATC or even a good enough "copy"...and that is a driver that has its own defaults and limitations.
I would just for the talk give an illustration: Dunlavy with basic driver line and sota result because of design dev choices.
So no, it is not the drivers that give the limit but if you do stupid choices. Beginn with the listenning room first.
My 2 c...only.
Good luck to find an ATC or even a good enough "copy"...and that is a driver that has its own defaults and limitations.
I would just for the talk give an illustration: Dunlavy with basic driver line and sota result because of design dev choices.
So no, it is not the drivers that give the limit but if you do stupid choices. Beginn with the listenning room first.
My 2 c...only.
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The desired directivity pattern actually is of quite some importance. But as more often is the case, this thread seems to start with the wrong end. First define your goals and your criteria. All of them. Or at least the most important ones. You’ll soon discover that not every driver you thought was perfect, will fit the bill. And that (well-chosen) criteria rule to make choices easier.
I recently fooled around with soft domes and waveguides. One very respectable unit that did well on a flat baffle did, eh, not so well in the waveguide. Big time miss. And no (basic) simulation could have shown me in advance. Lesson: shape and size of your baffle and enclosure dictate driver choice in an important way. The ATC and the like domes often are used in quite a wide baffle. Have a waveguide (Neumann/K&H). Like the cone mid drivers in Genelec main monitors.
So: where will your quest lead to? Are you prepared to design the system around your ‘perfect’ mid and will you let go of other goals that get out of reach because your mid dictates otherwise?
Wonder why, it worked for me, but it was in the early '80s with whatever brand RadioShack was re-branding. How big have you tried? The ones I used were fairly large.
In that it depends on the needs of the app, yes, most definitely; been there, done that with many a cheap driver; it was my DIY speaker design 'stock in trade' for all but the Altec, JBL, etc., level of performance, ditto manufacturers I had access to, i.e. there was no need for any 'middle range' class of drivers as one can see from researching what little was available from most manufacturers up into the late '70s.
That said, the power levels required were much lower overall except for the musical instrument (MI) range, but now it has expanded 'across the board' from subs to (super?) tweeters in all types of apps, so see the need nowadays for at least several 'bang/buck' ranges.
Factor in the (potential) power of DSP and basically all that really matters in a driver is does it have the power handling @ 'x' max distortion @ 'y' polar response over 'z' BW to meet the needs of the app. Really takes the fun out of DIY except for the typical casual DIYer that just wants 'bang/buck' in the smallest (im) practical box size.
In short, what's the point for having an F1 motor/gearbox in a family 'grocery/baby hauler' except 'bragging' rights?
That said, the power levels required were much lower overall except for the musical instrument (MI) range, but now it has expanded 'across the board' from subs to (super?) tweeters in all types of apps, so see the need nowadays for at least several 'bang/buck' ranges.
Factor in the (potential) power of DSP and basically all that really matters in a driver is does it have the power handling @ 'x' max distortion @ 'y' polar response over 'z' BW to meet the needs of the app. Really takes the fun out of DIY except for the typical casual DIYer that just wants 'bang/buck' in the smallest (im) practical box size.
In short, what's the point for having an F1 motor/gearbox in a family 'grocery/baby hauler' except 'bragging' rights?
I get quite nauseated at the constant Gedlee worship. Quite a few people believe everything they're told by people who have strong opinions about what matters and what doesn't pertaining to designing an accurate sounding set of speakers. I sincerely feel like there is alot of conflicting "advice" dispensed which often correlates to focus groups studies and other statistical info which isnt as controlled as it should be. Does he choose the people involved in these studies he cites or are they chosen by their eagerness to voice an opinion (often for some compensation) without being qualified to do so on the given subject? The reason I bring this up is simply too much leaning on psycho-acoustical studies and a general advising of "its good enough because I said so". His speakers use decent drivers, yet he claims those don't matter that much given his studies. In all fairness, he is a smart guy, but there is definitely some censorship of info going on IMO.
Bottom line for bringing this up is distortion does matter to a certain point and the type of distortion, where it resides and the proportionality of its individual components has alot of bearing on how audible it will be. You cannot make a blanket statement about distortion being virtually irrelevant, whether its being masked or not. You also can't state that hammering everything into shape with DSP makes one speaker virtually indistinguishable from another lower priced speaker with inferior, higher distortion motor design and mechanical components leading to a (not so good) sound signature of its own (which can't be corrected by any other means than throwing the driver into the trash and using a decent one instead). I can hear the difference. I dont need people telling me I can't hear a difference because overpaid people in lab coats tell me so. I'm sick of this repeated argument taking place over the same subject with the same strong opinions being forced onto those who disagree and don't drink the kool-aid.
Yeah no
i wont sell my tad drivers
and i agree its weird seeing mods throwing empty generalisations.
whatever at this point
i wont sell my tad drivers
and i agree its weird seeing mods throwing empty generalisations.
whatever at this point
Emotions usually don't help much in getting a clearer picture. Dr. Geddes has documented findings on distortion and they should be taken in the light of the circumstances. He never said that you can take whatever piece of rubbish drive unit you can find and make of it a spendid sounding device capable of world class performance. In fact, he has made the best of efforts to shed light on this matter on numerous occasion, and for that he deserves gratitude, while being polite at the same time. This is quite an achievement on forums considering what kind of people keep visiting.
Should anyone have better evidence or whatever working hypothesis to supplement existing knowledge on this matter, please feel free to post. It will be appreciated.
Should anyone have better evidence or whatever working hypothesis to supplement existing knowledge on this matter, please feel free to post. It will be appreciated.
Also worth noting that for example AllenB used nuance like "almost doesn't matter" and "not significant", so context is important again like in many discussions.
Key is to know what is more significant than something else. If one is trying to gobble up great sounding system there is lots of things to consider before even choosing drivers. Obviously "low distortion" is a goal for good system, but there are many others. When the system design seems nice then buy best drivers one can afford that fit the bill, simple as that, fuzz around drivers seem silly to me.
I mean, amount of distortion is irrelevant as long as its not the main turd, if room sound is bad then its not distortion fault but the system doesn't fit the room, or acoustic treatment is needed, which is more distracting? Buy better drivers to fix distortion but did the sound get any better because the worst offender is still there? Upgrade turntable, expensive power cord and so on, whats the problem? By all means buy best drivers. Ideal drivers don't exists so just use best you can have hands on for any speaker design, perhaps easiest thing in the world. But, there is only so much headroom one can get by swapping better same size driver, right? Back to design table most of the time.
One can use ideal drivers to come up with good system design and that probably means the system has enough SPL capability that distortion is again, irrelevant with most real driver options.
I think this is the case with Geddes message, as long as the sound is good in room, system that addresses statistically more audible issues like room modes, directivity, not too many crossovers to ruin step response. A system design that solved these statistically most important problems got so big it naturally has very low distortion so that it isn't very audible in home use. So, important to read what is his context, when system is made to fix the most audible issues distortion got fixed as well.
I think only thing Geddes says is that THD does not correlate perceived sound quality, which is the reason there is better metric that takes account proportion of each harmonic. If someone is concerned about distortion in their systems its not much of a challenge to buy few different drivers and test audibility. If one sounds better than the other then why not. It might be better room suiting alignment, better frequency response with given crossover and so on, not necessarily amount of distortion, that makes it sound better. Inverse could happen, if some cheap driver with poor distortion spec sounds better than some more expensive one its probably just frequency response difference, or bad system design. EQ them equal and check again if there is audible difference. Sure, when everything is fine enough also distortion gets it's show in spotlight, just buy better driver, or change the system design for better if it wasn't enough.
Most of you know all this so its preaching to choir 🙂 Design your system well, and use best drivers that fit the bill.
Key is to know what is more significant than something else. If one is trying to gobble up great sounding system there is lots of things to consider before even choosing drivers. Obviously "low distortion" is a goal for good system, but there are many others. When the system design seems nice then buy best drivers one can afford that fit the bill, simple as that, fuzz around drivers seem silly to me.
I mean, amount of distortion is irrelevant as long as its not the main turd, if room sound is bad then its not distortion fault but the system doesn't fit the room, or acoustic treatment is needed, which is more distracting? Buy better drivers to fix distortion but did the sound get any better because the worst offender is still there? Upgrade turntable, expensive power cord and so on, whats the problem? By all means buy best drivers. Ideal drivers don't exists so just use best you can have hands on for any speaker design, perhaps easiest thing in the world. But, there is only so much headroom one can get by swapping better same size driver, right? Back to design table most of the time.
One can use ideal drivers to come up with good system design and that probably means the system has enough SPL capability that distortion is again, irrelevant with most real driver options.
I think this is the case with Geddes message, as long as the sound is good in room, system that addresses statistically more audible issues like room modes, directivity, not too many crossovers to ruin step response. A system design that solved these statistically most important problems got so big it naturally has very low distortion so that it isn't very audible in home use. So, important to read what is his context, when system is made to fix the most audible issues distortion got fixed as well.
I think only thing Geddes says is that THD does not correlate perceived sound quality, which is the reason there is better metric that takes account proportion of each harmonic. If someone is concerned about distortion in their systems its not much of a challenge to buy few different drivers and test audibility. If one sounds better than the other then why not. It might be better room suiting alignment, better frequency response with given crossover and so on, not necessarily amount of distortion, that makes it sound better. Inverse could happen, if some cheap driver with poor distortion spec sounds better than some more expensive one its probably just frequency response difference, or bad system design. EQ them equal and check again if there is audible difference. Sure, when everything is fine enough also distortion gets it's show in spotlight, just buy better driver, or change the system design for better if it wasn't enough.
Most of you know all this so its preaching to choir 🙂 Design your system well, and use best drivers that fit the bill.
lolz, forgot to type Frequency response, perhaps the most obvious thing to hear and notice differences 😀
Food for thought everyone: what if there was ideal drivers available without any distortion and cone breakup, and you could afford them. How good your system would be or is there still some issues regardless?
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Quick thought experiment for fun.
Lets take from literature that speaker directivity is important for good stereo playback system in hifi application. What if we had ideal drivers, could we achieve for example omni response 20-20kHz to get perhaps ideal directivity? To get ~omni around 20kHz transducer (and construct) size would need to be about half of wavelength or so, one wavelength is 1.7cm give or take, sub 1cm. Lets just use traditional 1" for simple calculations, lets consider it omni enough.
Our ideal 1" transducer is capable of anything without electro-mechanical reality destroying performance. Lets calculate if we could have full bandwidth 20Hz - 20kHz from it. To maintain flat frequency response (simplified direct radiator example) volume displacement needs to quadruple every octave down. From 20k to 10k, to 5k, to 2.5k to 1.25k to 640, to 320, to 160Hz, 80Hz, 40Hz, 20Hz, roughly ten octaves. Quadruple length of one ten times is 1048576, so if 20kHz makes 0.01mm excursion for some SPL reaching same SPL at 20Hz would make it 0.01 * 1048576 = 10485mm excursion, so about 1048cm, or 10 meters, better wear goggles or cut down from the requirements somehow.
Revisit, system capability for 100dB SPL at 40Hz? sounds reasonable home hifi goal. Using table here https://www.diyaudio.com/community/threads/volume-displacement-for-spl-chart.5668/post-55869 says about 200cm3 volume displacement does it. 1" radius disk has about ~5cm2 of surface area for easy calculation, so to get 200cm3 / 5cm2 = 40cm p-p excursion. Much more reasonable than 10meters, but this is about twenty times of wavelength at 20Hz, and more than wl at 1kHz, would probably sound quite wobbly and have all sorts of combfilter happening to every direction at high frequencies. IMD?🙂 Also room would make the response not flat, especially on the low end.
See, still, even if we had ideal drivers from outer space our systems wouldn't be much better than what they are simply because sound wavelength varies quite wild and its all back to system design.
Lets take from literature that speaker directivity is important for good stereo playback system in hifi application. What if we had ideal drivers, could we achieve for example omni response 20-20kHz to get perhaps ideal directivity? To get ~omni around 20kHz transducer (and construct) size would need to be about half of wavelength or so, one wavelength is 1.7cm give or take, sub 1cm. Lets just use traditional 1" for simple calculations, lets consider it omni enough.
Our ideal 1" transducer is capable of anything without electro-mechanical reality destroying performance. Lets calculate if we could have full bandwidth 20Hz - 20kHz from it. To maintain flat frequency response (simplified direct radiator example) volume displacement needs to quadruple every octave down. From 20k to 10k, to 5k, to 2.5k to 1.25k to 640, to 320, to 160Hz, 80Hz, 40Hz, 20Hz, roughly ten octaves. Quadruple length of one ten times is 1048576, so if 20kHz makes 0.01mm excursion for some SPL reaching same SPL at 20Hz would make it 0.01 * 1048576 = 10485mm excursion, so about 1048cm, or 10 meters, better wear goggles or cut down from the requirements somehow.
Revisit, system capability for 100dB SPL at 40Hz? sounds reasonable home hifi goal. Using table here https://www.diyaudio.com/community/threads/volume-displacement-for-spl-chart.5668/post-55869 says about 200cm3 volume displacement does it. 1" radius disk has about ~5cm2 of surface area for easy calculation, so to get 200cm3 / 5cm2 = 40cm p-p excursion. Much more reasonable than 10meters, but this is about twenty times of wavelength at 20Hz, and more than wl at 1kHz, would probably sound quite wobbly and have all sorts of combfilter happening to every direction at high frequencies. IMD?🙂 Also room would make the response not flat, especially on the low end.
See, still, even if we had ideal drivers from outer space our systems wouldn't be much better than what they are simply because sound wavelength varies quite wild and its all back to system design.
GL wasn't all that polite when I expressed my concerns and questioned his methodology of obtaining the info in his studies.
I give people credit and respect where its due and expect the same in return when trying to contribute my own findings despite not having the academic title. I'm no dummy and not new to this speaker thing. I just wouldn't cite a bunch of psychoacoustic studies done on my own speakers that I feel are not as objectively scientific as they're being presented while I'm dismissing everyone else who disagrees as presenting findings which are labeled as subjective in his or her eyes if they don't agree or are being questioned on scientific validity. Brow beating people, questioning their knowledge and background isn't acceptable to me or should be accepted by others here attempting their best to contribute useful knowledge AND OPINIONS to further the cause of the diy community. In short, his interactions can be perceived as confrontational be default, which often wasn't provoked. This isn't how you treat others on here wishing to help. Open minded thinking is what often solves problems.
Belittling people about how they present their findings isn't productive or respectful. Forcing statistical information (in this case of GL often being self generated and possibly biased towards putting hinself into a spotlight) and even citing their way as being "academically correct" while others have to feel lectured and belittled is disrespecting and condescending.
Again, respect is given where its due and if you read my prior post I do give GL credit for his technical work and wisdom if its not presented in the light of self promotion or self elevation.
GL has also mentioned many times the compression driver alone doesn't have much at all to do with how a CD and WG perform as a package, IOW the WG or horn is what mainly dictates performance. I simply disagree with this and its the reason why I stated what I did in my last post.
Regarding respect - has to be earned, not bindly expected. Only Mother Theresa and Ghandi will receive my unconditional, undevided respect, as their work and dedication to help those in need regardless of their social status or background all deserve equal treatment. Everyone else is on the same level here. You'd be surprised at what you can learn from unlikely sources, as mediocre as they may often come across.