Someone on here mentioned a while back that a small full-range driver isn't ideal for high SPL applications (even when crossed over), because the sound deteriorates very quickly as you ramp it up.
Assuming we have a perfect amp, why is it that these small full-range drivers sound so awful when you begin turning it up?
With my test subject, a visaton FRS8M, not a cheap driver, but by no means the best, it didn't matter what slope I used on foobar, the sound was equally as bad at any given volume (assuming the speaker has begun distorting).
The sound goes from quite shouty (lots of sibilance) to screamy, lots of nasty midrange distortion, treble even worse, sounds like everything from guitar to vocals is screaming at you.
I'm curious - why is this?
Other people have noticed it, so it's not just me.
Thanks for any input
Chris
PS, I have tested this on other speakers, and they all seem to have a certain maximum volume, then the sound gets very bad very quickly.
Assuming we have a perfect amp, why is it that these small full-range drivers sound so awful when you begin turning it up?
With my test subject, a visaton FRS8M, not a cheap driver, but by no means the best, it didn't matter what slope I used on foobar, the sound was equally as bad at any given volume (assuming the speaker has begun distorting).
The sound goes from quite shouty (lots of sibilance) to screamy, lots of nasty midrange distortion, treble even worse, sounds like everything from guitar to vocals is screaming at you.
I'm curious - why is this?
Other people have noticed it, so it's not just me.
Thanks for any input
Chris
PS, I have tested this on other speakers, and they all seem to have a certain maximum volume, then the sound gets very bad very quickly.
I have mentioned this (it is a *paper* driver issue) on quite a few occasions, but for the most part I have been shot down. I have heard everything. 'It's your amp. It's your room. It's your cables. It's your bass drivers etc etc'. Please ignore the excuses. It's the PAPER.
I rejected Lowther, AER (germany) Visaton, vintage and Fostex untreated drivers because of this. They are all useless. I believe the problem is paper fibers 'rubbing' together. Your solution is a 'treated' paper driver, something similar to the Fostex F200A or a driver with a plastic cone.
I would not give you five bucks for any speaker in the, say, Fostex FE lineup because they sound awful to me. I consider any speaker with this problem a poorly-engineered unit. Years ago I bought a pair of Bose 301. I was unhappy with them right away and this was long before I knew anything about hifi. The paper tweeters and woofer were to blame.
HOWEVER - paper is a fantastic material for diaphragms. I just don't feel any magic with metal or plastic cones, myself. So what I need, and what you need, is paper - with tweaks. I use the Audio Nirvana Super Eight with the Enable treatment and it is quite unwilling to be harsh. I have to push it near its limits to hear alot of ear ripping. And actually the stock form is better than any of the other brands I have mentioned, but the treatment is another level indeed. No, it doesn't have quite the resolution of the more expensive drivers, but it blows them away in every other capacity.
Furthermore, I don't think I would buy the $20k Feastrex alnico driver either, because I know what will happen. Money is no guarantee of satisfaction! I just wish I had learned this early, before I wasted thousands on pretty paperweights. I might be able to save you grief if I say just one thing: let your ears decide, not the people here.
I rejected Lowther, AER (germany) Visaton, vintage and Fostex untreated drivers because of this. They are all useless. I believe the problem is paper fibers 'rubbing' together. Your solution is a 'treated' paper driver, something similar to the Fostex F200A or a driver with a plastic cone.
I would not give you five bucks for any speaker in the, say, Fostex FE lineup because they sound awful to me. I consider any speaker with this problem a poorly-engineered unit. Years ago I bought a pair of Bose 301. I was unhappy with them right away and this was long before I knew anything about hifi. The paper tweeters and woofer were to blame.
HOWEVER - paper is a fantastic material for diaphragms. I just don't feel any magic with metal or plastic cones, myself. So what I need, and what you need, is paper - with tweaks. I use the Audio Nirvana Super Eight with the Enable treatment and it is quite unwilling to be harsh. I have to push it near its limits to hear alot of ear ripping. And actually the stock form is better than any of the other brands I have mentioned, but the treatment is another level indeed. No, it doesn't have quite the resolution of the more expensive drivers, but it blows them away in every other capacity.
Furthermore, I don't think I would buy the $20k Feastrex alnico driver either, because I know what will happen. Money is no guarantee of satisfaction! I just wish I had learned this early, before I wasted thousands on pretty paperweights. I might be able to save you grief if I say just one thing: let your ears decide, not the people here.
With single cone and whizzer cone drivers, running full range there are "zones on the main and whizzer cone that do not impress energy into the air in a minimum phase manner. Means they have some tendency to emit or not emit or emit more than they should at various points on the cone, for different frequencies and different amplitudes. Very little work on this issue is in the public domain, though it is known about. You can get a visual reference from Baranek's book "Acoustics", or, you can access my white paper on EnABL here as the same drawings are available but not the instructive text..
standingwaves
Look through until you see some drawings of circles with bands of pluses and minuses on them. The cone of the Visiton is actually pretty similar to these drawings, done back in the early 50's.
There is a solution. It will quell most and quite possibly all of your troubles, it is called EnABL and can be found on this forum. I have attached a txt file with most of the locations for commentary and how to obtain the benefits. It is free for you to use and is quite proficient at solving these problems.
Bud
standingwaves
Look through until you see some drawings of circles with bands of pluses and minuses on them. The cone of the Visiton is actually pretty similar to these drawings, done back in the early 50's.
There is a solution. It will quell most and quite possibly all of your troubles, it is called EnABL and can be found on this forum. I have attached a txt file with most of the locations for commentary and how to obtain the benefits. It is free for you to use and is quite proficient at solving these problems.
Bud
Frequency modulation - Doppler effect?
Amplitude modulation - driver non-linearity with displacement?
Cone break-up?
All of these are reduced in a multi-way system - have you tried those drivers crossed over with a tweeter and a sub? Might help prove things one way or another, or more likely cause more confusion...
Amplitude modulation - driver non-linearity with displacement?
Cone break-up?
All of these are reduced in a multi-way system - have you tried those drivers crossed over with a tweeter and a sub? Might help prove things one way or another, or more likely cause more confusion...
I have tried a very crude method of enabl treatment, prior to my research into it. I used acrylic paints (orange, of course), and went around a wharfedale 4" full range speaker, and used white on a pair of FRS8 drivers. I used the thinnest paintbrush I could find, but still made a far mess of it all.
Pics of that attached.
I'm going to try a test with some 4" poly coned speakers, see what's what.
Pics of that attached.
I'm going to try a test with some 4" poly coned speakers, see what's what.
Attachments
Got that right!. EnaBL just allows you to cease to worry about the out of band breakup problems, that even sharply rolled off multiway systems suffer from. And then there is that beguiling extra 60 db or so of coherent information that shows up, underneath the typical 40 db down cut off of coherent information, that typical drivers labor under.
chriss, you REALLY want to order Ed Lafontaines EnABL kit. see the txt attached above for the thread here on diy. Learning this simple system of application, though tedious, will take you right to the level of competence you need to get to, before you work on something near and dear to your heart. I teated inclinedplanes drivers for him, and he is being very straight about how well they work, and they didn't have a lot to apologize for, before treatment, just three shriek zones.
Bud
Full range drivers have their own limitations as well as advantages like any other driver. Cone brake ups are usually not filtered out and drivers are run crossover less. Cone material and motor design allows the driver to have a very extended frequency response on axis but usually at the expense of other things like limited excursion. It's a trade off. Distortion character is different. It's a bit like spreading butter over toast.
Most of the full range drivers are low power low x-mas and aren't meant to play very loud.
Most of the full range drivers are low power low x-mas and aren't meant to play very loud.
Now reporting on the poly coned speaker.
The speaker is in it's original box, which was around £10 for the pair (they were the last in the shop, and they wanted rid. RRP around £25)
Driven to near excursion limits, it still sounds reasonable. I expect that some of the nastyness in the sound was from a clipping amp - I put it past 3oclock... The speakers were cheap, but still sounded better than my mains, at higher volumes, albeit with a complete lack of bass (small, sealed box, with a cheap driver - what's to be expected?).
This investigation supports Inclined Plane's idea that the fault is in the paper cone.
The next step is: I have some car speakers, with a treated paper cone (coated, looks almost like PVA), and a poly whizzer. Will report on those. The only thing I've done is add a phase plug, made of lego.
The effect doesn't seem as bad, even though they are cheapy car speakers. Could it be the coated paper?
The speaker is in it's original box, which was around £10 for the pair (they were the last in the shop, and they wanted rid. RRP around £25)
Driven to near excursion limits, it still sounds reasonable. I expect that some of the nastyness in the sound was from a clipping amp - I put it past 3oclock... The speakers were cheap, but still sounded better than my mains, at higher volumes, albeit with a complete lack of bass (small, sealed box, with a cheap driver - what's to be expected?).
This investigation supports Inclined Plane's idea that the fault is in the paper cone.
The next step is: I have some car speakers, with a treated paper cone (coated, looks almost like PVA), and a poly whizzer. Will report on those. The only thing I've done is add a phase plug, made of lego.
The effect doesn't seem as bad, even though they are cheapy car speakers. Could it be the coated paper?
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I assume both drivers being tested are identical in every respect save for cone material (which will have been made of equal wight in order to keep all other functional aspects equal, and which have been designed for exactly the same response)?
As mentioned elsewhere in this thread, there are no short answers, let alone one that can be universally applied, other than 'no, they do not always "rip your ears off" at high SPLs' (although that is also subjective depending on how you define 'high.' A longer set of things to consider: linear excursion. How much is there? How big is the driver? What Fs, how is it loaded (or intended to be loaded), and where does Doppler / AMD start to play a significant role? Does it have a whizzer? If so, at what frequency does the mechanical XO between the cones come into effect? Motors and suspension? What are the tolerances like (applies to everything else too)? Cones, and their inherent break up modes -where do these occur in the frequency spectrum? How high (or low) a Q are the resulting resonances? How severe are the peaks? How well designed is the driver generally -is it actually a well-engineered unit that achieves it's design goals? What actually were the design goals? All of these need to be considered; it's not possible to simply state 'one material good, one material bad' (whatever they happen to be).
FWIW, most of the time paper is employed in wide-band units for it's high stiffness-weight ratio, which gives you a head-start in efficiency. Lot more to it than that of course, but that's one reason. The infamous 'Lowther shout' people often discuss is largely due to the breakup modes of the very thin, uniform thickness cone, with no attempt to damp them down (it appears they do in fact calm over time as things soften up, and that's intentional, if somewhat difficult to predict / engineer with any certainty). It's not necessarily paper itself; paper cones can be as well behaved, or better, than some other materials. It's what you do with it / your goals that dominate.
Take two units of roughly the same size for e.g.; Mark Fenlon's CHR70 and Fostex's FE103E. Are they designed for the same purposes? No, not really. Do they both achieve their design goals? Yes indeed. Do they sound the same? Of course not. On the one hand, we have a metal cone unit tuned for a rather 'British' sort of sound, and intended to be used in relatively small / simple enclosures, likely with SS amps. It's a forgiving driver, targeting primarily people new to DIY, and is easy to get decent results from, which is ideal for inexperienced builders. On the other hand, we have a classic, high[er] efficiency paper cone driver, which is rather more lively / raw, primarily intended for use in back-horns, with low DF amplification. It's a much more specialised / focused driver, far less forgiving of components upstream, harder to work with, and somewhat more characterful. The raw acceleration factors of the two units gives one indication of these different priorities inherent to the two units:
CHR70: Γ = 638.33
FE103E = Γ = 2104.76
Where Γ = theoretical maximum acceleration in meters per second per second per ampere.
Name your poison.
As mentioned elsewhere in this thread, there are no short answers, let alone one that can be universally applied, other than 'no, they do not always "rip your ears off" at high SPLs' (although that is also subjective depending on how you define 'high.' A longer set of things to consider: linear excursion. How much is there? How big is the driver? What Fs, how is it loaded (or intended to be loaded), and where does Doppler / AMD start to play a significant role? Does it have a whizzer? If so, at what frequency does the mechanical XO between the cones come into effect? Motors and suspension? What are the tolerances like (applies to everything else too)? Cones, and their inherent break up modes -where do these occur in the frequency spectrum? How high (or low) a Q are the resulting resonances? How severe are the peaks? How well designed is the driver generally -is it actually a well-engineered unit that achieves it's design goals? What actually were the design goals? All of these need to be considered; it's not possible to simply state 'one material good, one material bad' (whatever they happen to be).
FWIW, most of the time paper is employed in wide-band units for it's high stiffness-weight ratio, which gives you a head-start in efficiency. Lot more to it than that of course, but that's one reason. The infamous 'Lowther shout' people often discuss is largely due to the breakup modes of the very thin, uniform thickness cone, with no attempt to damp them down (it appears they do in fact calm over time as things soften up, and that's intentional, if somewhat difficult to predict / engineer with any certainty). It's not necessarily paper itself; paper cones can be as well behaved, or better, than some other materials. It's what you do with it / your goals that dominate.
Take two units of roughly the same size for e.g.; Mark Fenlon's CHR70 and Fostex's FE103E. Are they designed for the same purposes? No, not really. Do they both achieve their design goals? Yes indeed. Do they sound the same? Of course not. On the one hand, we have a metal cone unit tuned for a rather 'British' sort of sound, and intended to be used in relatively small / simple enclosures, likely with SS amps. It's a forgiving driver, targeting primarily people new to DIY, and is easy to get decent results from, which is ideal for inexperienced builders. On the other hand, we have a classic, high[er] efficiency paper cone driver, which is rather more lively / raw, primarily intended for use in back-horns, with low DF amplification. It's a much more specialised / focused driver, far less forgiving of components upstream, harder to work with, and somewhat more characterful. The raw acceleration factors of the two units gives one indication of these different priorities inherent to the two units:
CHR70: Γ = 638.33
FE103E = Γ = 2104.76
Where Γ = theoretical maximum acceleration in meters per second per second per ampere.
Name your poison.
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That's what I was thinking. And also "paper" is a pretty vague label for a material since it could be a composite of various materials.
I've taken pot shots at Bud before but really I don't know what Enable does and can only speculate based on existing drivers which utilize patterns molded into the cones and surrounds. Anyway just making it clear I do think it probably changes the sounds and possibly improves it. I just don't understand the patent and all that minimum phase stuff. I suspected some sort of damping of standing waves on the cone or something along those lines might be happening. I would be a little afraid to use it on certain drivers where the manufacturer has already considered or tried to reach a critical damping of the driver.
I wasn't really thinking about EnABL, more cone material in general. FWIW, I know EnABL isn't supposed to be about damping per-se, but that aside, I agree (I'm sure Bud would too) that care would need to be exercised in some cones. Some of Mark Fenlon's latest for e.g. are to exceptionally tight tolerances / thin multi-forming of aerospace aluminium, so trying to apply something to them IMO is asking for trouble, if only for the sake of not damaging it by physical contact. You put a pen anywhere near one, there's a good chance it would go straight through, or at least cause deformation, they really are that thin.
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At 15 years of age, I have no measurement equipment, apart from my ears.
I'm looking at getting an SPL meter at some point, but I've no idea what to look for apart from accuracy, ie, +/- 1dB, and frequency range.
As far as I could control, the speakers were compared in similar conditions. Same width cabs etc for baffle-step. However, the drivers were of different sizes, and it was therefore impossible to use the poly one in my mains without wrecking them.
Chris
I'm looking at getting an SPL meter at some point, but I've no idea what to look for apart from accuracy, ie, +/- 1dB, and frequency range.
As far as I could control, the speakers were compared in similar conditions. Same width cabs etc for baffle-step. However, the drivers were of different sizes, and it was therefore impossible to use the poly one in my mains without wrecking them.
Chris
Don't waste your $ on SPL meter. If you going to be serious about it, measuring microphone, inexpensive mixer with phantom power for the mic is what you need. And a software, some of which is free. As you will learn about measuring the drivers you will also understand relationship between cone materials and your preferences in sound. Most of the problems that you are talking about can be located within half an hour or less. CSD will show all your cone brake ups, distortion sweeps will clear why 1 driver sounds better to you then the other one. And of cause on and off axis frequency response of the driver will show your preferences. You own TS parameter data will allow you to build very precise loadings and so on.
You are typing on a pretty powerful piece of measurement equipment
If you already have a decent soundcard and a PC - note some of the big guys here don't even use a fancy card just their onboard sound - you can use HOLM Acoustics
It might look a little complicated at first.
Oh yeah you need a mic. That would help. If it requires phantom power you will need either an outboard pre with phantom power or a soundcard with a mic pre and phantom power already. There are some cheap ones out there but they limit the frequency response if it only does 44.1 or 48kHz sample rate. I tend to think the soundcards that can do hi res 96kHz or above give the cleanest measurements - by keeping the cutoff frequency far away from the audible range.
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