New 8" fullrange from SB Acoustics sb20frpc30

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JohnR


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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #1 on: 17 Feb 2020, 03:38 am »
The bass are awesome for a 8'' driver and price surprising low.
Seems response til 13/14kHz, great release.

wushuliu

Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #2 on: 17 Feb 2020, 06:40 am »
Sweet.

planet10

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #3 on: 17 Feb 2020, 11:53 pm »
I does look like an inexpensive driver. Biggish box i expect, but should be good sealed like the SEAS FA22 (and already comes w phase plugs). I haven’t run sims so that is a guess.

dave

wushuliu

Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #4 on: 18 Feb 2020, 12:45 am »
I'm a SB Acoustics fanboy. I have not been disappointed in any of their drivers, even the budget ones. I loved their regular 8" woofer. Great bang for the buck.

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #5 on: 18 Feb 2020, 12:49 am »
I like his made in house paper cones, they perform a a bit more flat midrange than the regular paper cones used by other manufacturers.

Scottmoose

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #6 on: 20 Feb 2020, 01:30 pm »
What do you mean by 'the regular paper cones used by other manufacturers?' What 'regular paper' are you referring to, and do you exclude from that cones made with

-Additional papyrus, bamboo, linen etc. fibres
-Banana, hemp, manilla etc. pulp bases
-Multi-layer cones with differential construction
-Pulps impregnated with various additional material e.g. charcoal
-The many types of coated paper cones
-The many types of pulp cones with internal structural ribs e.g. fibreglass

I think you'll find the majority of paper cones used in high quality audio drive units fall into the above categories in one way or the other. ;) The truth is there is no such thing as 'regular paper' as such. There are an almost infinite variety of paper pulps and additives to pulps that can be and are used in audio and other industries. Nor, unfortunately, can you simply say 'the paper of xyz type is the cause of a flat midrange'. I don't like to rain on your parade, but it doesn't actually work that way. It can be, and certainly is one very important feature, but it's not the only factor. A handful of others that play significant roles in determining the response behaviour are:

-Cone size, mass and geometric profile
-Any additional sub-cones, pole-piece extensions etc. present
-Surround design and construction,
-Voice-coil design and coupling
-Edge damping
-Adhesives employed
-Coatings present
-Spider design
-Overall motor geometry

SB produce some excellent drivers (and a few less good), and I regularly use them myself, but this is not simply down to the cone material.

Scottmoose

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #7 on: 20 Feb 2020, 01:35 pm »
.

FullRangeMan

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #8 on: 20 Feb 2020, 06:00 pm »
Thank Scottmoose for your paper class.
A few years ago when I bought from Perry Pecker he mentioned that the color of the cone changes the sound of the FR drivers, do you could tell us the musical changes obtained with the cone colors ?

Scottmoose

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #9 on: 21 Feb 2020, 02:11 pm »
Well, if we rephrase to 'functional changes', then there are a few aspects to that.

-If you take a given pulp mix and add a colourant during the production process, then there will be some degree of change to the structure; internal damping or stiffening, slight increase in mass etc. How much depends on the pulp and the colourant used. In the overwhelming majority of cases, the difference in these conditions will be tiny and far below measureable or audible thresholds. Production tolerances of components and finished drivers are far more significant, so to all intents and purposes, the colour has no impact upon behaviour

-If a colourant also contains significant extra components or compounds, you may get greater differences. However, such additives will be chosen in the design stage for functional reasons rather than colour itself

-External coatings applied to a cone may contain colour and they will affect technical performance, either by adding damping or stiffening the substrate (which depends on the specific coating type used). Like the above though, the colourant is not the cause of such differences, but the mass, elasticity etc. of the coating

-If significantly different pulp mixes (which may happen to be of different colours) are used in otherwise identical drivers, it is quite possible there will be significant differences in behaviour which will be audible ; this is due to the different material properties of the papers though

For example, take Dave P10's modified drivers. Typically he can colour pale paper cones as part of the modifications he makes, but the colourant itself has no measurable or audible affect on their behaviour, the differences come from the additional edge damping, diffraction blocks, damping or stiffening coats applied to the front or rear of the cone (or both) that he adds.

Outside of technical audio of course, it's known that different colours have different psychological effects upon many sighted people, so it might be possible this would affect some people. If so though, this is in the realm of psychoacoustics and psychology rather than technology as such, and naturally it would not affect anyone who couldn't see it!

FullRangeMan

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #10 on: 21 Feb 2020, 06:14 pm »
Thanks for your detailed insight.
As colors affect the light frequencies, my limited intellect thought colors could affect sound frequencies.

Scottmoose

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #11 on: 21 Feb 2020, 08:10 pm »
Not at audio wavelengths. We're a bit lower in frequency. ;)

triumph

Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #12 on: 6 Jun 2021, 07:46 am »
Well, the driver has completely disappeared from SBA, and even though some distributors are still showing it is coming, an insider source told me they had much manufacturing troubles that this driver is now back on the drawing boards.

On another funny level, regarding colors....
Worked in an outdoor gear shop in my younger days.
There was this weird customer that would always come up with strange reasoning when buying his stuff.

One day, he came in wanting a "warm" jacket for winter.  Proceeded to show him a model that was considered our warmest.  I told him, it came in blue and red.
He looked at me funnily, then said, "Are you really going to tell me that the blue one is as warm as the red one?"
I replied that they are the same model, with the same amount of insulation inside...
He said that he was no fool, that of course he knew that red is a warm color, and blue is a cold color... there was no way the blue jacket could be as warm as the red one. 

Sometimes, you just can't argue, and said, "you got me!  Of course the red one is warmer."  He left with the red jacket happily.

I think this story would apply to some audiophiles too, when shopping for audio stuff.

FullRangeMan

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #13 on: 7 Jun 2021, 12:59 am »
Well, the driver has completely disappeared from SBA, and even though some distributors are still showing it is coming, an insider source told me they had much manufacturing troubles that this driver is now back on the drawing boards.

On another funny level, regarding colors....
Worked in an outdoor gear shop in my younger days.
There was this weird customer that would always come up with strange reasoning when buying his stuff.

One day, he came in wanting a "warm" jacket for winter.  Proceeded to show him a model that was considered our warmest.  I told him, it came in blue and red.
He looked at me funnily, then said, "Are you really going to tell me that the blue one is as warm as the red one?"
I replied that they are the same model, with the same amount of insulation inside...
He said that he was no fool, that of course he knew that red is a warm color, and blue is a cold color... there was no way the blue jacket could be as warm as the red one. 

Sometimes, you just can't argue, and said, "you got me!  Of course the red one is warmer."  He left with the red jacket happily.

I think this story would apply to some audiophiles too, when shopping for audio stuff.
https://www.discoveryexpresskids.com/blog/how-does-color-affect-heat-absorption

https://sciencing.com/science-experiment-kits-for-middle-school-13763608.html

https://lightingdesignstudio.co.uk/colour-temperature/

https://en.wikipedia.org/wiki/Color_temperature#Correlated_color_temperature

FullRangeMan

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Re: New 8" fullrange from SB Acoustics sb20frpc30
« Reply #14 on: 7 Jun 2021, 12:59 am »
Double post.