Scan-Speak sliced cone drivers .

[alan-1-b]

For their sliced paper cone drivers Scan-Speak state :- "reduces break-up modes in the membrane dramatically" . I don't expect perfection , but these are expensive compared to conventional cone types made by SEAS ; Peerless ; Morel etc ... thus can any users of any of the Scan sliced cone models comment on the degree of improvement - particually in the midrange - compared to the other brands I listed ? Eg:- the Scan 18W/8531GOO frequency plot shows a small peak at about 3.3kHz and another at about 6kHz - I would expect some resonance at both . Scan do not publish Cumulative Spectral Decay plots , nor any type of Time Domain data and I haven't been able to find any via web searches {is any given anywhere ?} , thus I don't know the degree of break-up nor its duration . How audible are these compared to similar in plain cones ? There are similar artefacts on the plots for the 15W/**** and 12M/**** sliced cone models . Any comments about audible advantages or problems from users of any of the sliced cone models would be most welcome . Also , the "Low Loss linear Suspension" which Scan state for the surrounds - is this made of solid rubber or foam rubber or of some other material , eg:- Santoprene , etc ... ? , thankyou ,

 

[Eton]

They have to justify the outrageous high prices for a plain paper cone driver somehow and still get the customer to buy it. Hence sliced paper.

 

[lndm]

A gentle rise in response from below 1k to the upper mid area is a useful trait for box speaker use as baffle step compensation can be dealt with simultaneously with the crossover inductance.

Some speakers have an ugly bump at a couple of k or so and this should probably define the upper limit for your crossover.

If the ss succeeds in smoothing this region, then they are probably doing a good thing.

P.S. I don't use these drivers (I do use scanspeak).

 

[cotdt]

it's too expensive! I wonder how it sounds compared to Seas Excel W18NX and Peerless Exclusive.

Reducing break-up nodes tends to actually have a negative impact on the sound IMHO. It tends to lower and hide the break-up nodes but I prefer pistonic drivers with high breakup nodes, even if it is a bigger breakup.

 

[lndm]

Reducing break-up nodes tends to actually have a negative impact on the sound IMHO. It tends to lower and hide the break-up nodes

That's an interesting perspective, also you can't deal with what you can't see. I wonder what Zaph has on his site about these drivers.

 

[pinkmouse]

...Reducing break-up nodes tends to actually have a negative impact on the sound IMHO. It tends to lower and hide the break-up nodes...

Hmm. Interesting use of logic...

Lets say I grow nuts on a remote island. There are two types of birds on this island, red ones, that eat my nuts, and green ones that don't.

Now if we apply your logic to my island, if I shoot all the red birds, I will lose no nuts and have a full harvest. What difference is there between that situation and one where red birds never existed? None, for all practical applications, but you seem to be saying there is.

 

[alan-1-b]

Thanks guys !

Thanks guys for your comments - which I've thought about . ____ Cotdt , bigger breakup will then necessitate a higher slope cross-over - not a problem in some cases . There will always be breakup in cone drivers , but lesser will be lesser audible surely !?__ , and even a high slope cross-over won't drop the breakup region down through the full audible dynamic range of the music , or to the lower limit of the speakers' capability , thus I think either option in cone drivers will involve some degree of compromise . ______ Indm , I couldn't find anything on Zaph's site about these drivers when I last looked - I'm hoping some enthusiast will analyse them as I don't have the type of equipment to do so . Which Scan-speak drivers do you use ? ____ Their other cone types' drivers all have a resonant peak immediately prior to roll-off , thus I'd have to use a higher slope cross-over than I'd prefer to . I'll probably use the Scan D2905/97000 tweeter . I'm still curious about the material used for the surrounds if anyone owns these drivers and can recognise it .____ Thanks again for the comments ,

 

[lndm]

I use the 18w/8545k. I use a first order electrical rolloff but I use notch filtering for the cone breakup and an earlier peak.

These drivers are reportedly difficult to deal with at the top end, but this challenge is not insurmountable. They are sensitive to the crossover, you need to tweak carefully but when you do, they fall in to place magnificently.

They have a particularly sweet bottom end and are a good match for my 9500's.

 

[cotdt]

When using very dampened cones, the breakup is usually part of the passband. Although the cone breakup is harder to see in graphs, it occurs earlier in frequency than rigid rones. Observe the Seas L18, which for a driver of its size has a breakup very high in frequency (peaks at 7kHz), while poly cones of the same size tend to start break up right after 1kHz yet it is used to 3kHz typically.

The near-invisible breakup of well-dampened cones has negative consequences on the sound and I claim to hear a degradation. For one, there is higher even-order distortion, and a rougher frequency response in the passband which contributes to linear distortion. The evidence for this are the many drivers that use the same motor but different cones, so direct comparisons are possible.

Anyhow, I'm interested in these sliced-cone drivers and am curious as to how they sound. I've held one in my hand before and the cones are pretty rigid. I'm looking for 15cm cones as clean and detailed as the Peerless Exclusive or Seas Excel, but with better bass output.

 

[tinitus]

Hi, well, some like the uncoated version which is said to be more bright - frequency response show a rise from about 1khz on all those drivers - on a plot it looks pretty awfull and most people tend to deal with this using a very big coil - personally I dont like such approach because it messes up phase - I rather let it be as is and I think its not a problem because its a very wide spread soft rise in frequency - and I place crossover point relative high which makes the elevated sensitivity even wider and maybe therefore of less concern - but must admit I am working with a nearly 90db 3way speakersystem and it seems this 5" lacks a bit in sensitivity - but it plays very nice and if it dont the fault is in crossover - simple as that
an interesting replacement for me could be the midrange version, which then is a 4ohm driver - but I guess thats not in your interest as you want a driver with good bass also

 

[ShinOBIWAN]

Hmm. Interesting use of logic...

Lets say I grow nuts on a remote island. There are two types of birds on this island, red ones, that eat my nuts, and green ones that don't.

Now if we apply your logic to my island, if I shoot all the red birds, I will lose no nuts and have a full harvest. What difference is there between that situation and one where red birds never existed? None, for all practical applications, but you seem to be saying there is.

I'm with you Al.

I've played around with drivers that have high Q resonances such as the Seas Magnesium and the lesser Alu cones. I've also listened to low Q well damped drivers such as the ATC 9" SC with treated paper cones.

The ATC sounds by far the best out of those. The Excel W22 are criminally overpriced for the quality on offer, I didn't like them anyway, very average sounding. Almost night and day in direct comparison. So I fail to see any correlation between stiffer cones offering better whatever and damped cones offering lesser something.

 

[alan-1-b]

Indeed ShinOBIWAN , I listened to a pair of ATC spekers a few years ago - either the SCM20 or the then SCM10 , I've forgotten the model but not likely the sound ! , thus my continued interest in damped paper cone drivers . I prefered the ATCs to Monitor Audios with all metal cone -not that Mon. Audios are bad , they were good though less clear detail than the ATC and less impact in transient response , but transient response is an ATC specialty that few can match ._____ I think those of us commenting in this thread may have different priorities , or perhaps hear somewhat differently - {apparently people do} . ______ I read on another forum that Zaph is being sent a sample of one of the Scan 15W sliced cone models to test , thus hopefully soon we can see some evidence , so keep watch there cotdt . ______ Tinitus , I agree with your ideas and I prefer not very large coils . You won't get 90dB from a Scan 12M sliced cone midrange unfortunately . ______ Indm - first order electrical rolloff and notch filtering requires a lot of careful work , though you seem to like the challenge , and probably most of us in DIY don't mind that !. _____ Thanks for all the comments fellows ,

 

[tinitus]

Alan, no not 12M, but there is a 15M midrange which should give about 90db, and with fairly low Fs at 35hz and +/-3mm linear exc.
Its a midrange but actually it has better specs. than many midwoofers at this size - but offcourse bass will be relative lower at 90db sesitivity.

 

[gfinlayson]

Unfortunately, I've not heard most of the other drivers listed for comparison, but having had a pair of 18W8531G00 for the last couple of months, I can say that they're very good drivers indeed. There's no noticeable distortion, or audible cone break-up.

They do have a slightly 'lush' sound to them which may not be to everyone's taste. Tony Gee used the 18W4531G00 with the dreaded (price tag) R29 in his Optimo two way floorstander. He reckoned it was one of the best 2 ways he'd ever heard.

Al (Pinkmouse) has heard my speakers with the sliced paper drivers - what say you, Al?

 

[pinkmouse]

Yes, I should have actually mentioned this earlier, but I was distracted by the specious logic.

The Scans do sound very good, and I was very impressed by Greame's implimentation. If I could afford them, I would certainly buy a couple to play around with. Personally, I think the "lushness" in the system is more room related than anything else, and once the renovations are finished the problem should be less apparent.

BTW Greame, the pre is finished, pic here. Want to have a listen some time? Oh, and I have a book on recording studio monitoring that has some good ideas on room treatment that you might want to have a look at.

 

[gfinlayson]

Al,

That is one very nice looking preamp. I'm definitely up for a listen. My place or yours? Ale will be provided

I wouldn't mind a look at that book of yours as well. I found some ideas here which look interesting, but I'd welcome any other suggestions.

Graeme

 

[alan-1-b]

I apologise tinitus , I was mistaken - I was confusing memory with a low sensitivity SEAS midrange driver I had been thinking about and also the low sensitivity 15W Scans . I'm pleased to see the Scan 5" mid is 90dB , though if I used a Scan mid I'd probably use the 12M - 89dB - as it extends its high frequency response flatter on Scan's plot - pity is only in 4 ohm ! ______ Graeme , is that 3.3kHz peak not audible in any way in your 18Ws ? - a plot posted on another site shows +5dB there for 2 samples of the 4 ohm version ! ___ Are you crossing over exactly on that peak by any chance , and with at least 12dB slope ? ___ I would have thought now that one would have to cross over more than 1 octave below 3.3k . No , I can't see any evidence of major problem for certain on the plots on Tony Gee's page , however I cannot decipher the Horizontal Axis scales' numerals to check what's happening exactly where . Perhaps with the unusual cross-over he has used - {if that schematic is correct , as it is not the First Order slope on the tweeter that he states in text} - most of that 3.3k peak has been reduced , and if so , very clever ! I prefer to use a cross-over which allows like polarity connection for woofer and tweeter . ____ Thanks for posting the link to Tony Gee's project - its very interesting ! ______ Your preamp looks good Al , I hope you are enjoying the listening ! ___ Is the book you mention the one by Tony Newell , if I've remembered his name correctly , ?

 

[pinkmouse]

Is the book you mention the one by Tony Newell , if I've remembered his name correctly ?

Yup, that's the one.

 

[alan-1-b]

Graeme , I forgot to ask in the above , what does the surround look as if made from on your sliced cone Scans ? ___ Is it likely rubber , or a coated foam , or something else ? ___ Scan state only "Low Loss linear surround" for all their sliced cone models , but state Rubber for some of their other cone type models . Some of their previous models had Foam surrounds - such I do not want as they deterirate too soon . That has occurred with other drivers I have owned , thus if I buy expensive Scan drivers I want long service life ! , thanks , Alan .

 

[alan-1-b]

Al , co-incidence - your reply slipped in whilst I was typing my addition ! ___ I have seen T.Newell's book - it seemed good , unfortunately I didn't have time to look at it thoroughly but will at next opportunity . I looked at all his test results for the small sized Studio Monitoring speakers - near the end of the book . Thanks for your reply .