More FR drivers in various array configs is the most obvious, and to my experience quite acceptable solution to the problems you mention above.
You will improve directivity and surface area, at the slight cost of sweetspot imaging (which can be had to if you arrange for the extra drivers to be switched off).
You will improve directivity and surface area, at the slight cost of sweetspot imaging (which can be had to if you arrange for the extra drivers to be switched off).
I'm in partial agreement with what you've stated...however, if the midrange is as "open" as you've indicated FR are, and many here value, then you've already achieved 90% of an ideal speaker. "The music lives in the midrange, all else is adornment."
The solution to this problem is to add subwoofers for a "Distributed Bass" system. This is accomplished, according to who tells the tale, by three, or four, subwoofers carefully positioned within the room. Dr. Earl Geddes has a supplied a number of detailed discriptions of the method here on diyAudio.
I might add that multiways are just as much in need of this method as any speaker, dispite denials by some.
By using a "Distributed Bass" system, you'll certainly get the precision that you need from the FR, along with really deep, uniform bass throughout the room, something that, for what it's worth, no pair of multiways is able to accomplish by themselves either.
Best Regards,
TerryO
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Squeak,
FWIW, there aren't many arrays that I've heard that were anywhere near as good as a point source for imaging and a lucid, coherent presentation. If you build a floor to ceiling vertical ribbon or planar system you will have a cylindrical wavefront that can be pretty good. However, anything shorter (like you see all the time) then you begin to have timing (phase) and comb filtering problems. Bessell Arrays can work, but are actually only coherent in farfield applications, which rules them out for just about any "normal" listening space.
Power tapering, etc., introduces additional filtering with all the detrimental effects that signal conditioning may possess and actually serves (IMHO) more as a bandage, on an already flawed concept.
Best Regards,
TerryO
Hi all,
The one thing that I notice listening to my FH3's and CHP-70's is they disappear much quicker than any others I've listened to.
I can then concentrate on the music.
Jim
The one thing that I notice listening to my FH3's and CHP-70's is they disappear much quicker than any others I've listened to.
I can then concentrate on the music.
Jim
There are plenty alternatives to just vertical. There is horizontal angled (cell horn style), front and back and up and front facing, to mention some. Just look at Planet 10 site for some inspiration.
Sure you won't get the imaging of one driver, but nearly every solution is a compromise.
Sure you won't get the imaging of one driver, but nearly every solution is a compromise.
I also want to add that, while I have made a few fullrange speakers (and heard several more), and I like the openness for acoustic music, I never heard a sole FR speaker that was as balanced and tonally neutral as compact Quad 2-way speakers (11L or 12L, I forgot) which I heard a few times. These things were tuned to sound as close as possible to their flagship electrostatic speakers, and indeed they were shockingly good and superbly finished, all for a reasonable price.
The best FR experience I ever enjoyed was the application of an expensive AER driver in a front horn, actively filtered and supported with a bass horn. These were designed by Bert Doppenberg (BD Design). Very transparent, and dynamic with enough precise bass.
The best overall sound I ever heard was in 4 instances:
- big Proac speakers driven by Nagra electronics.
- enormous vintage Tannoy coaxial speaker in and old fashioned horn cabinet (EDIT: after googling I think it was a vintage Westminster Royal cabinet)
- big vintage Altec 2 way speakers (low-crossing tweeter was an enormously wide horn)
- (a long time ago, my memory may be clouded) big JBL 4435 monitors (in essence 2 way, with 1 of the woofers only for the lowest frequencies)
In all these cases the sound didn't seem to come from the speakers, it was just "hanging there" in the air, with incredible effortlessness.
Therefore, I can see in my future FR units being used around the computer, as surround speakers, in the bedroom, etc; and I also see something like those Great Plains replica coaxial Altecs in my main system...
The best FR experience I ever enjoyed was the application of an expensive AER driver in a front horn, actively filtered and supported with a bass horn. These were designed by Bert Doppenberg (BD Design). Very transparent, and dynamic with enough precise bass.
The best overall sound I ever heard was in 4 instances:
- big Proac speakers driven by Nagra electronics.
- enormous vintage Tannoy coaxial speaker in and old fashioned horn cabinet (EDIT: after googling I think it was a vintage Westminster Royal cabinet)
- big vintage Altec 2 way speakers (low-crossing tweeter was an enormously wide horn)
- (a long time ago, my memory may be clouded) big JBL 4435 monitors (in essence 2 way, with 1 of the woofers only for the lowest frequencies)
In all these cases the sound didn't seem to come from the speakers, it was just "hanging there" in the air, with incredible effortlessness.
Therefore, I can see in my future FR units being used around the computer, as surround speakers, in the bedroom, etc; and I also see something like those Great Plains replica coaxial Altecs in my main system...
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That was me "going on about it" 😛 and yes I'm also puzzled and bemused by how some well known current model full range drivers could be so much worse than some that are close to 40 years old, and were made without the benefit of modern design and measurement techniques.
I actually wrote a long semi-rant post at the time in reply to planet10 about what I thought was wrong with the design of the FE207E / FE206E and the state of progress of modern full range drivers in general but my browser crashed before I posted it and it's quite soul destroying trying to rewrite a long message like that from scratch when you know it will never come out the same, so I left it...🙁
As for the FE207E - why are the resonance problems so much worse than the Coral Flat 8's ? They're both 8" whizzer cone full range drivers, both have fabric surrounds, and both are the same sensitivity. (about 94dB/W/M)
Close mic'ed measurements show that the huge 2.6Khz resonance shown on my CSD plots of the Fostex does indeed emanate from the whizzer cone not the main cone, while the 2.2Khz whizzer cone resonance from the Coral's is so minimal that it barely shows up on the FR or CSD plots at 1 metre, and I have to close mic the whizzer cone to even identify what frequency it's at. Why ?
I think the biggest difference between them is the whizzer cone design - the Fostex has a smaller (approx 60mm) straight sided (conical) whizzer cone with a crimped edge, while the Coral has a larger (80mm) curvilinear whizzer cone similar to some Lowthers.
As far as I'm concerned, a conical whizzer cone is a fundamentally flawed design that might have been passable in the 1960's but shouldn't still be in use in expensive drivers in the 2000's let alone the 2010's. When you have a conical cone with a surround terminating it at the edge you can get away with it to some extent but a whizzer has no support around the edges, and relies entirely on it's own inherent stiffness and structural integrity.
Although a conical cone has some strength in the direction of bending waves emanating from the centre and travelling outwards it has almost NO strength against bell modes where the paper is trying to bend and ripple around the edges, because in this axis it's essentially a straight piece of paper. There is rigidity only in one of two axes relative to the surface of the paper. Crimping the edge may give a little bit of extra stiffness right at the edge, but most of the cone is still weak in one axis.
A curvilinear cone on the other hand has curvature in two dimensions over the entire surface, and anyone who knows about engineering knows that this is fundamentally far stiffer and more rigid than a one dimensional curve of the same material and thickness. The curvilinear cone is very rigid in both bending axes, so if the paper is sufficiently crisp it very strongly resists bell mode resonances that easily form in conical cones.
If the superiority of curvilinear cones for high frequencies was known in the 60's and 70's, why are some full range drivers still being made with conical whizzer cones ? Laziness ? I'm baffled.
That's not to say that a curvilinear whizzer cone is some kind of panacea and will automatically work well - it still has to be designed right and made with the right materials (too soft or heavy and it still resonates, for example old cones damaged by crushing or soaking up moisture) but a conical whizzer cone is a fundamentally broken idea, so why use it in this day and age ?
The other main source of resonances of both drivers is from cone breakup of the main cone - which occurs at about 4Khz on both, since they have the same diameter cone.
Both drivers have conical main cones instead of curvilinear, (bad idea IMO) but the Coral has 3 stiffening/decoupling rings pressed into the cone near the perimeter which stiffens the edge against bell mode resonances, while the Fostex does not.
Even unmodified the 4Khz resonance of the Coral is significantly less than the Fostex, although it is still somewhat noticable as "zingyness".The way I dealt with this was to put a pattern of small adhesive foam blocks on the rear of the main cone near the perimeter in a pattern that was derived from a lot of trial and error. (Measuring to get the flattest response from 3-5Khz, cleanest CSD, and a lot of listening tests over weeks/months)
This comes back to a comment someone made a couple of pages ago - If it's possible to improve the response of a driver and clean it up significantly with damping or other mods, why don't the manufacturers just do it themselves ? (With the implication also being that maybe those that are doing damping mods on drivers are just fooling themselves...)
Again, I'm a little bit stumped.
If we're talking about 40 year old full range drivers like the Coral's that can be improved by a damping modification that's understandable when you consider that at the time they were made they were probably designed with a LOT of trial and error, since they didn't have the benefit of today's advanced computer aided design and measurement systems.
No CAD, no finite element analysis materials modelling, no laser interferometry to study cone breakup patterns, no FFT/MLSS measurement systems, no way to measure CSD, and so on. T/S parameters had not yet been invented.
About all they would have been measuring is frequency response with a swept sine wave on a pen plotter paper chart, and maybe looking at THD and IMD products on an analogue spectrum analyser, or maybe even just a simple notch filter based distortion measurement system. And listening. Cone and magnet system designs would have been drafted and designed on paper. 🙂
The fact that a few vintage full range drivers compare favourably or even exceed many modern designs is either (a) a testament to the incredible ingenuity, insight, and brilliance of those engineers (plus a huge amount of trial and error) despite working with extremely limited facilities by today's standards or (b) a sad indictment of today's driver designers who have all the modern design and measurement facilities they could wish for, a huge history of previous designs to look at for inspiration, but somehow can't churn out much better.
It seems almost like full range drivers today are seen as a boutique product (which I guess is true, unless we're talking about computer speakers or TV speakers) which they simply aren't willing to invest REAL money in developing and improving, instead they seem content to basically make copies (sometimes poor ones) of vintage designs and churn them out, without any real effort to push the state of the art in full range cone design.
In the process, some of the design mistakes already made decades ago (like conical whizzer cones) are being made all over again - presumably by a new generation of driver engineers who have been tasked with designing the token full range driver models for their company - who don't have the hard won experience of those vintage driver engineers who are now long gone and didn't pass on their knowledge.
Multi-way drivers are where all the intense driver development effort seems to be focused unfortunately.
That's not to say that there aren't some good full range drivers and that progress hasn't been made, but I think progress in full range driver design is FAR behind where it could be with today's modern design and measurement techniques, and that does make me sad. The fact that it's possible to take some current models of full range driver, make some DIY tweaks to them that drastically improve their performance shows that there is room for improvement.
Personally I think the challenge of designing a large (8" or bigger) full range driver with very smooth and extended treble is fascinating, and I don't think current drivers are anywhere near the limits of what's possible if real effort and modern technology was poured into solving the problem instead of making copies of yesteryears designs...
The only differences between the two drivers is the 206E has a stronger magnet thus a higher sensitivity and lower Qes, and also has a copper shorting ring to lower inductance, so has an upwards sloping treble.
I have both the 206E and the 207E and the cone design is identical - both have the same resonance problems sadly. 🙁
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You mean they don't have to be vertical? Who would have ever thought...?
😕
I guess you're right, I'll have to to look at that Planet 10 site for some inspiration. Is it a Disco or some kind of expensive nightclub?
BTW: You wouldn't have a link to it handy, would you?
Best Regards,
TerryO
A great post by Simon (DbMandrake)
It is indeed remarkable how some of the vintage FR drivers hold up against current production. While i have never heard them, old Siemens Klangfilm speakers are said to still be amazing.
It is indeed remarkable how some of the vintage FR drivers hold up against current production. While i have never heard them, old Siemens Klangfilm speakers are said to still be amazing.
DBmandrake :
I can tell you after being involved in the business, some are FOS and some even require extra payments to have their drivers meet specs.🙄
Terry:
If you add a sub then it's no longer an FR, a 2 way ...?..🙂
I can tell you after being involved in the business, some are FOS and some even require extra payments to have their drivers meet specs.🙄
Terry:
If you add a sub then it's no longer an FR, a 2 way ...?..🙂
I've been collecting the Coral Flat and Beta sometime back.. Yes, these drivers are pretty amazing even by today's standards.. IMHO the the Coral Designers did an excellent job.. selecting the paper and cone design ..
I had a pair of Coral Beta 8 which had some cone rubbing.. and I had another pair of spare Flat 8 .. so I orginally want to transfer the cone from the Flat over to the Beta .. but after looking closely I realised that the 2 cones were not identical .. the paper and the annular ring design on the cones were different.. so in the end I didn't do the transplant.
Btw I have also Klangfilm and the Sabas.. I still prefer the Corals..
I had a pair of Coral Beta 8 which had some cone rubbing.. and I had another pair of spare Flat 8 .. so I orginally want to transfer the cone from the Flat over to the Beta .. but after looking closely I realised that the 2 cones were not identical .. the paper and the annular ring design on the cones were different.. so in the end I didn't do the transplant.
Btw I have also Klangfilm and the Sabas.. I still prefer the Corals..
Well, if that's the case, then if your main driver had a whizzer it would be a 3-way....I guess.
Actually on some forums they try to define it as any speaker that uses a driver that produces 7 octaves or more. I believe that it's actually pretty flexible. I certainly don't lose much sleep over it one way or the other.
Best Regards,
TerryO
Hi all,
Many years ago I made a pair of Lowther Mini-Acoustas they sounded very nice indeed, but the chassis of the PM6's, back bit and front bit, kept coming undone it wasa right P in the A to tighten the bolts whilst keeping the coil centred.
Nice sound badly made.
Ah well.
Jim
Many years ago I made a pair of Lowther Mini-Acoustas they sounded very nice indeed, but the chassis of the PM6's, back bit and front bit, kept coming undone it wasa right P in the A to tighten the bolts whilst keeping the coil centred.
Nice sound badly made.
Ah well.
Jim
Have you listened to the 8" Tang Band full-rangers? They're rather good. The Visaton B200s are also supposed to be good, too - curved cone profile, and no whizzers!
Nice post, anyway. I'm yet to hear the Fostex 8" drivers, so can't offer an opinion on them.
Chris
No I haven't had the opportunity to hear either. I do like the look of the Tang Band W8-1772 but until hearing and measuring them I couldn't say for sure.
Their whizzers are curvilinear and look well designed, although the main cone doesn't have any stiffening rings near the edge..... but the most important part of cone design is the material properties and their internal damping which is not something you can tell just from looking at them.
I've been perpetually in the poor house the last couple of years, so no chance to buy new drivers but when the money situation improves I may take a punt on a pair and see what I can do with them as they're quite reasonably priced. 🙂
The B200 I'm not so sure about, just based on looking at it, but then again I haven't heard them either.
I have a pair of the smaller Corals. And they measure almost ruler flat from 300 Hz right up to 10 kHz with nearly no resonances (CSD) and then they fall off with a very nice smooth slope. Why don't the newer smaller FR drivers manage that? I would kill for a such a driver.
Sorry i missed that. I've enjoyed your posts. I could never live with the Fostex stock, and much prefer the smaller drivers.
Do keep in mind that when the Corals were made, they were the state-of-the-art and respresented the pinnacle of Japanese FR art at a time when (or shortly after) 1-ways ruled. (i rue the day that Audax (i think it was) bought them and just shut them down). The Fostex on the other hand are medium to low priced drivers in today's market and still suffering from all the loss of the art from mult-ways coming to the fore.
dave
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