"...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..."
This makes sense if dealing with the breakup entails modifying/lowering the freq of the pistonic behavior.
If damping can be added w/o significantly increasing mass (not sure what % mass is increased when applying a coating to a paper cone; anyone know?), then I don't see a downside.
This makes sense if dealing with the breakup entails modifying/lowering the freq of the pistonic behavior.
If damping can be added w/o significantly increasing mass (not sure what % mass is increased when applying a coating to a paper cone; anyone know?), then I don't see a downside.
Sliced paper cones. Don't know about the cone effort to all but as overall I've seen some distorsion measurements from the new 15cm Revelator and it isn't that good. Considering the price it's poor, 1/5th cost Vifa can do the same.
Not that they wouldn't sound good, low distorsion and subjective pleasure don't hold hands in every situation. But for the price at least I'd expect better measurable performance.
Jussi
Not that they wouldn't sound good, low distorsion and subjective pleasure don't hold hands in every situation. But for the price at least I'd expect better measurable performance.
Jussi
Alan,
Sorry I haven't come back to you until now. Things have been busy today.
The 3.3 kHz peak on the Scan isn't audible at all. The crossover is a third order series @ 2.5 kHz, so there's a lot of attenuation (14 - 15 dB) by the time you get to 3.3 kHz.
Here's my in room FR:
There's a slight blip at ~ 3 kHz, about 1.5 dB, but it's not audibly detectable.
As tinitus said, the surround is a rubbery material, but it's also very soft and very, very flexible. I guess this is why Scan-Speak refer to it as 'low loss' - I can't imagine it inhibits cone movement much.
Graeme
Sorry I haven't come back to you until now. Things have been busy today.
The 3.3 kHz peak on the Scan isn't audible at all. The crossover is a third order series @ 2.5 kHz, so there's a lot of attenuation (14 - 15 dB) by the time you get to 3.3 kHz.
Here's my in room FR:
An externally hosted image should be here but it was not working when we last tested it.
There's a slight blip at ~ 3 kHz, about 1.5 dB, but it's not audibly detectable.
As tinitus said, the surround is a rubbery material, but it's also very soft and very, very flexible. I guess this is why Scan-Speak refer to it as 'low loss' - I can't imagine it inhibits cone movement much.
Graeme
Zaph said:
Driver was tested by Finnish monitor manufacturer Genelec as they test new drivers when they come into market. Unfortunately I personally don't have that slip and don't remember the exact model. But as results I consider them very reliable since this company does these measurements very professionally with HQ equipment (Audio Precision) in anechoic room and one of the manufacturers key features in low THD on given SPL.
Naturally this result can only match for specific measured model but as for overall it didn't seem that promissing so I don't know do they bother measuring any more of them.
From Tymphany manufacturers Peerless is propably most "professional" and technically preferenced manufacturer. I heard that SS R&D doesn't even measure THD anymore. The reason I don't know, do they want to create "musical" drivers that have their own distinct signature?
At least older "classic" models also have good to very good distorsion performance as well.
Jussi
To Graeme , Noah , and Tinitus ...
Thanks Tinitus , and Graeme for the information ! - no worry about delay , we all have to do other things in life !! ____ A 3rd order Series cross-over ! - I have never used a Series cross-over , though have read that some enthusiasts say such produce better sound than Parallel cross-overs . Perhaps Series is better at reducing the amplitude of resonant peaks - perhaps owing to the interaction of the reactive components when connected in such way ? ___ Perhaps you were lucky and received samples of the Scan driver which had less peaking around 3kHz . What-ever the case , I should try a Series Cross-over some time - no , I haven't Searched the topic in this Forum yet . _______ Noah , here is some data for you on Mass increase when a coating has been applied to a plain paper cone , from some older SEAS data sheets . The plain paper coned A17RC and the coated paper CA17RC were otherwise identical in all physical / mechanical construction . Both are 6 1/2 inch midwoofers . A17 has moving mass of 8.5 gram and CA17 has moving mass of 10 gram . This Mass includes all moving parts , including the voice coil , etc ... The Air Load in baffle is an additional 1 gram for both drivers . The added 1.5 gram of coating caused the Fs to drop from 40Hz to 37Hz ; Qes to rise from .45 to .48 ; Qms from 2.2 to 2.3 ; Qt from .37 to .40 . Vas remained the same at 46 litres ; Sensitivity dropped from 89dB to 88dB/W/m . There is less peaking in the upper midrange of the CA17 frequency response plot , and less amplitude resonance in its Step Response than shown for the A17 . Distortion plots for both show similar amounts of distortion but in slightly different areas of their frequency response . Yes , SEAS used to publish Step Response and 2nd and 3rd Harmonic distortion plots , and unfortunately no longer do this - I wish they would re-commence doing such ! ___ I hope this is of use to you , Alan .
Thanks Tinitus , and Graeme for the information ! - no worry about delay , we all have to do other things in life !! ____ A 3rd order Series cross-over ! - I have never used a Series cross-over , though have read that some enthusiasts say such produce better sound than Parallel cross-overs . Perhaps Series is better at reducing the amplitude of resonant peaks - perhaps owing to the interaction of the reactive components when connected in such way ? ___ Perhaps you were lucky and received samples of the Scan driver which had less peaking around 3kHz . What-ever the case , I should try a Series Cross-over some time - no , I haven't Searched the topic in this Forum yet . _______ Noah , here is some data for you on Mass increase when a coating has been applied to a plain paper cone , from some older SEAS data sheets . The plain paper coned A17RC and the coated paper CA17RC were otherwise identical in all physical / mechanical construction . Both are 6 1/2 inch midwoofers . A17 has moving mass of 8.5 gram and CA17 has moving mass of 10 gram . This Mass includes all moving parts , including the voice coil , etc ... The Air Load in baffle is an additional 1 gram for both drivers . The added 1.5 gram of coating caused the Fs to drop from 40Hz to 37Hz ; Qes to rise from .45 to .48 ; Qms from 2.2 to 2.3 ; Qt from .37 to .40 . Vas remained the same at 46 litres ; Sensitivity dropped from 89dB to 88dB/W/m . There is less peaking in the upper midrange of the CA17 frequency response plot , and less amplitude resonance in its Step Response than shown for the A17 . Distortion plots for both show similar amounts of distortion but in slightly different areas of their frequency response . Yes , SEAS used to publish Step Response and 2nd and 3rd Harmonic distortion plots , and unfortunately no longer do this - I wish they would re-commence doing such ! ___ I hope this is of use to you , Alan .
Interesting, that's more added mass than I would have guessed.
Re controlled damped breakup, the part that is unaesthetically satisfying is the element of chaos introduced.
It just seems so much more right to stay in piston range and have the cone perform as the amplifier commands, rather than "doing its own thing", even if it does result in flat response.
Re controlled damped breakup, the part that is unaesthetically satisfying is the element of chaos introduced.
It just seems so much more right to stay in piston range and have the cone perform as the amplifier commands, rather than "doing its own thing", even if it does result in flat response.
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