JohnK, I really admire your magic in math and your pragmatic and genius approach to equalising in general – but there are qualities of a driver that ain't accessible from specs nor by "curve shaping" (I'm sure you know).
There are may shortcomings of upper class speakers (like the fancy and so well regarded SEAS' for example) that are widely accepted in Hifi and DIY for centuries now – I really don't know why.
Some of this shortcomings ain't easy to overcome (like Thermal Compression for example) – OK – it might not be an easy task to develop a wire for VC application that's zero temperature coefficient – so I don't argue that.
*But* there already was a time when speaker people knew that surrounds have its typical sound (KEF people did demonstrate this first - AFAIK).
As for rubber – I no longer can stand it – its simply not necessary to accept what I would call a gross tonal botch.
You know – I'm usually after sublime second order effects – but this coloration isn't – its apparent anytime in music reproduction and in any speaker with that kind of surrounds.
Its simply a matter of consequence to drop that impertinence – no matter what the market tells you.
The attitude in this thread after PA speakers might be heavily driven from high efficiency (and its implications) but sonically it also may have an unconscious layer in the absence of that specific "rubber sound".
I tried a B&C PA speaker before and its been a pretty good unit for the intended range with even better specs, down to CSD plots – but the cone did render music in a fashion, I didn't like in the long run (though it definitely had it's bright sides as well).
Hence what I was looking for was a *non*-PRO speaker and a *non*-Hifi speaker and a *non*-exotic (exorbitant price) speaker
The one I have choosen isn't the only one in that niche - but one that isn't well known (from own experience at least) - so I give it a recommendation now and then.
Michael
There are may shortcomings of upper class speakers (like the fancy and so well regarded SEAS' for example) that are widely accepted in Hifi and DIY for centuries now – I really don't know why.
Some of this shortcomings ain't easy to overcome (like Thermal Compression for example) – OK – it might not be an easy task to develop a wire for VC application that's zero temperature coefficient – so I don't argue that.
*But* there already was a time when speaker people knew that surrounds have its typical sound (KEF people did demonstrate this first - AFAIK).
As for rubber – I no longer can stand it – its simply not necessary to accept what I would call a gross tonal botch.
You know – I'm usually after sublime second order effects – but this coloration isn't – its apparent anytime in music reproduction and in any speaker with that kind of surrounds.
Its simply a matter of consequence to drop that impertinence – no matter what the market tells you.
The attitude in this thread after PA speakers might be heavily driven from high efficiency (and its implications) but sonically it also may have an unconscious layer in the absence of that specific "rubber sound".
I tried a B&C PA speaker before and its been a pretty good unit for the intended range with even better specs, down to CSD plots – but the cone did render music in a fashion, I didn't like in the long run (though it definitely had it's bright sides as well).
Hence what I was looking for was a *non*-PRO speaker and a *non*-Hifi speaker and a *non*-exotic (exorbitant price) speaker
The one I have choosen isn't the only one in that niche - but one that isn't well known (from own experience at least) - so I give it a recommendation now and then.
Michael
How would you describe the "rubber sound"? I ask this because though a surround does radiate some small amount of the wave, it's primary function is to terminate the cone. If its impedance is matched well with the cone, the termination is good and any breakup is greatly reduced. If not, the "sound" is more likely the non-optimally controlled breakup. Certain cone materials have a better match with certain surround types, so I have a hard time considering a surround "sound" that is not related to the mechanical impedance (mis)match.
Dave
dlr said:
Simply forget about termination – its a too technical approach for this.
What I meant is a repetition to what's been said here many times – you cant get rid of a certain sonic characteristic once a specific material is used .
There are children playing at the neighbours place right now – I can hear them throwing around an aluminium tube.
Why am I certain that its of aluminium and not from brass?
Michael
mige0 said:
Michael
I agree with John here. Your "black magic" beliefs in some "unquantifiable sound quality" are not held by me that's for sure. There is nothing that you can hear that cannot be measured - just because they are not! And I have found that drivers are a small factor in a loudspeaker system design, not a major one as you imply.
Your subjective assesments aside, there is no reason why a good 8" driver should cost as much as is being talked about here. It's the unsubstantiated beliefs, like yours here, that allow companies to do this by simply claiming some "magical sound that defies sciientific explaination". Surely, that statement alone is worth a couple hundred bucks if the right person says it!
And to say "Not!" is heresy.
gedlee said:
Uhh, I should get money from Jantzen if we continue on that.
But serious,
Earl, you should know that I usually don't advocate some "black magic" bogus.
I'm with you that there *might* be a way to measure that characteristics I was focusing at – but if you would have gone a step further saying that you could equalise it out – I would have to disagree.
Happily you basically said the characteristics I am concerned about don't exist.
Thats just fine for me (as I add "for you" to that statement of yours)
As for costs and " my unsubstantiated beliefs " and "magical sound that defies sciientific explaination" – I'd be glad I would have found a speaker at close to zero cost doing the trick (and really - why isn't only a single type 8" / a single type 10" ... on the market ) – but I'm definitely *not* gonna ask you for recommendation as you don't seem to have any feeling / sensibility for the relevance of my aim.
And thats fine for me too - you do have other qualities...
Michael
mige0 said:
That really doesn't answer the question and the analogy is not apt. One could reasonably say that an aluminum cone has a sound unique from a brass cone, but the surround as a damping material doesn't have it's own "sound", it primarily alters the sound of the cone to which it is attached. Rubber surrounds can outperform other materials depending on the cone material used, it's not the "sound" of the surround intruding.
Dave
badman said:
Of course it's radiating, but it's primarily a function of how well or badly it terminates the cone. If it terminates well, it significantly dampens the breakup. If not, it radiates quite differently and largely related to the breakup. So the question posed is still not answered.
Dave
dlr said:
dlr said:
Dave, its hard to discuss a subset of subtle characteristics on a level of simple and pure mechanics – hence I gave the example I had at hand – in the hope you could grasp the point.
If I try to keep in your perspective – sure - I don't doubt that termination of cone movement (bending in different directions) is an important thing to consider if you chose a material for the surrounding of the speaker (if you are a speaker designer – which I'm not).
If we look at piston operation of a cone (instead of the break up region ) don't you agree there is no termination ongoing but a mere fulling movement of the surround is happening?
So would you agree in that - *if* we would assume for a moment that even a dampening material – as you call it (but the surround as a damping material doesn't have it's own "sound",) – would have unique sound characteristic – there would be a overlay of that characteristic to the general perception?
If you *would* agree to my former question – what makes you so sure that
1) any surround material is of 100% dampening
2) there is *no* sonic characteristic to dampening material in general
???
Both statements ain't correct at any closer look, anyway.
First there is no such material that does not at least have some minimal internal structure (yes there are - but these would drip from basket and cone over time) meaning some kind of stiffness (= spring quality)
Second (internal material) dampening by its own isn't of pure good for us (as outlined recently in an other thread):
Dampening through material kneading is related to internal friction.
Now – there is a distinct difference between different forms of dampening a mass spring system.
- first we have the possibility to transform energy proportional related to the distance (of movement) – which is the case of friction related dampening in general
- second we have the possibility to transform energy proportional related to velocity – which is the case of a cars shock absorber and for the dampening effect to the cone by the motor.
The first case has the gross disadvantage to add inherent waveform distortion to the original force over time stimulus.
This is overlooked constantly when people think of dampening as a cure for each and everything.
Hope this of any value for you.
Michael
You've made a number of mis-statements and bad assumptions about what I said. I grasp your point, but I disagree with it. If one does not address the termination, it's mostly just hand-waving.
Both statements are mis-statements and bad assumptions and I do not agree. I clearly stated in post 5297 that it is primarily a function of termination. This is not purely damping, but it is the fundamental nature and intent. It damps to prevent reflections that occur if there is a mechanical impedance mismatch between cone and surround.
The second statement is yours, not mine. You have yet to define the sonic contribution concisely.
None of this addresses the question, yet again. Damping through appropriate mechanical impedance matching is the primary function (to prevent continued confusion) of the surround. It cannot do that without damping, otherwise reflections will occur and that means resonances, e.g. breakup.
So I would ask again, how would you describe the "rubber sound"?
Dave
Termination of the cone is not just an important thing to consider, it is the primary thing to consider.
No. It could be poorly terminated in this range and the driver would not by pistonic in that region. Attach a stiff cardboard surround and see how the cone then moves in what was once pistonic.
No. If it terminates properly it will move in such a way that it acts as an extension of the cone. It goes back to mechanical impedance of the termination.
Both statements are mis-statements and bad assumptions and I do not agree. I clearly stated in post 5297 that it is primarily a function of termination. This is not purely damping, but it is the fundamental nature and intent. It damps to prevent reflections that occur if there is a mechanical impedance mismatch between cone and surround.
The second statement is yours, not mine. You have yet to define the sonic contribution concisely.
None of this addresses the question, yet again. Damping through appropriate mechanical impedance matching is the primary function (to prevent continued confusion) of the surround. It cannot do that without damping, otherwise reflections will occur and that means resonances, e.g. breakup.
So I would ask again, how would you describe the "rubber sound"?
Dave
Perhaps this might help, the B&W 800 Series whitepaper:
http://www.bowers-wilkins.com/display.aspx?infid=800
Look at the Apendix: FST midrange driver: B&W has done some laser interferomety research on how the surround affects standing waves and ended up with the "surroundless" driver.
They also say that the surround resonance/sound might NOT be visible in the freq response plot, but - in their opinion - still affect the sound:
"The fundamental resonance results
in a peak in the steady-state amplitude
response, when the outer edge of the cone
and the surround both move more than in the
simple pistonic motion case. The first harmonic
involves the cone moving more than it should in
one direction, while the surround moves in the
opposite direction. Whether this results in a dip,
peak or no change in the amplitude response
depends on the relative area velocity of the
cone and surround, but more often than not it
is a dip, often referred to as the surround dip."
So there might be more that just the mechanical impedance - or rather the match might just be not good enough.
http://www.bowers-wilkins.com/display.aspx?infid=800
Look at the Apendix: FST midrange driver: B&W has done some laser interferomety research on how the surround affects standing waves and ended up with the "surroundless" driver.
They also say that the surround resonance/sound might NOT be visible in the freq response plot, but - in their opinion - still affect the sound:
"The fundamental resonance results
in a peak in the steady-state amplitude
response, when the outer edge of the cone
and the surround both move more than in the
simple pistonic motion case. The first harmonic
involves the cone moving more than it should in
one direction, while the surround moves in the
opposite direction. Whether this results in a dip,
peak or no change in the amplitude response
depends on the relative area velocity of the
cone and surround, but more often than not it
is a dip, often referred to as the surround dip."
So there might be more that just the mechanical impedance - or rather the match might just be not good enough.
dlr said:
There are no words to tell a blind about color - if you haven heard by yourself (which I'm sure *you have* - telling form your findings on your page, which I occasionally have visited)
So maybe you better ask (or tell) what's behind that you insist on?
Regarding the rest - we could go on arguing point by point - but I'd rather offer capitulation...
Michael
PS
If you'd like to start a thread about - do a summary and I'll come over - to cross our swords !
mige0 said:
FlorianO said:
I wouldn't disagree with anything here.. but at the same time I don't think you understand the "custom" process from a driver manufacturer.
The "custom" nature is in the configuration of the parts and the TS params.. not in providing anything that they normally don't handle.
Want/Need a larger magnet? - in stock.
Want a cone and/or dust cap with a different type of material? - in stock.
Want to try a phase plug? - in stock.
Want/Need to use a treated foam surround? - in stock.
(..note that "in stock" doesn't necessarily mean on hand, but rather "in the supply chain".)
Basically the designer gives target data for the driver and works with the manufacturer to provide something near this target. (..then the designer "fiddles" with non-TS specific elements to achieve the "sound" they are looking for.)
In the case of the JA8008 the basic parameters required a larger magnet and the foam surround. The driver is essentially 2 db more efficient than the one I posted (..probably the same magnet), so the eff. difference is mostly in the use of the foam surround.
Of course (generally) the requirement for the designer having the opportunity to do this is to purchase a certain number of drivers.
(EX.s - Eminence 50 units, Ciare 20 Units, AT - 1 Unit.)
You can call the driver "custom", and it is. To the manufacturer however it isn't custom (..at least not in the way we think of it).
Of course NONE of the above isn't to suggest that the driver doesn't sound better than other Seas drivers. I have no doubt that Troels spent a great dealt of time and effort to achieve a very good sounding driver. However, remember that none of his work and time is factored into the cost.. its basically all "mark-up" by Jantzen. The amount of that "mark-up" is IMO unconscionable (..but, when compared to other commercial offerings may still provide good value).
Wow, a hot topic. I mostly agree with Dave (dlr). The surround needs to control the cone termination or the modal effects in the cone become much worse. Therfor A good surround IS better than no surround. Hence, in that sense, maybe it does have a "suround sound" - its called "better". The fact that someone may not like it subjectively is not the issue, or even relevent. The surround plays a key role in achieving a good speaker with a minimum of aberations. (But controlling these are all well know.)
The fact is that no speaker should be used above the point of the first surround resonance because no speaker is pistonic in that region. If you are using any cone well into its modal breakup then of course it will have a "characteristic sound" - its called "bad", "colored" and "inaccurate" and all speakers in this region will sound "bad" in different ways, but they are all still "bad". Some people like these different sound and argue ad-infinitum about which "bad" is "better". I, personally would never use a driver beyond the first surround resonance and only up to it if it is well controlled. But after that you'd better be taking it out of play or it will be an audible problem. When this is done the driver itself ceases to be very important and it all becomes system design.
The fact is that no speaker should be used above the point of the first surround resonance because no speaker is pistonic in that region. If you are using any cone well into its modal breakup then of course it will have a "characteristic sound" - its called "bad", "colored" and "inaccurate" and all speakers in this region will sound "bad" in different ways, but they are all still "bad". Some people like these different sound and argue ad-infinitum about which "bad" is "better". I, personally would never use a driver beyond the first surround resonance and only up to it if it is well controlled. But after that you'd better be taking it out of play or it will be an audible problem. When this is done the driver itself ceases to be very important and it all becomes system design.
mige0 said:
Sure there is, it just requires some thought. Freq. and Temp. are two aspects that can be described to a blind person and evoked in a manner consistent with color.
I'll give it a "go"..
Foam surrounds - generally better transients. Less damped sounding with better sustained harmonics. Can provide greater detail, but often adding lower level noise (..rather like an LP with surface noise vs a CD). Sometimes having a paper'ish (low treble "hash" sound) sounding reflection from the surround itself. (..all of this depending a great deal on the partnering diaphragm material and its reaction to the surround.)
Often capable of providing 1.5-3 db gain in eff. compared to rubber in the same design.
ScottG said:
There are the caveats, "depending a great deal on the partnering diaphragm material" and "in the same design". This appears to be in agreement with what I said, so I'm puzzled by the apparent contradiction with the rest of your post.
Surrounds need to be chosen to work optimally with the cone to be used. In one case, foam may be best. The SS 21W/8554 comes to mind. In another case, rubber may be preferable. Many of those come to mind.
It's not self evident that for any individual case where one surround type is less effective (say rubber was less effective for the 8554) that by extension all drivers will perform better with foam.
Dave