What's up with the Kenrick "KRS Artificial Leather" surrounds?

[BMWCCA]

The large thread over on AK about an owner's latest "dream system" (second this year) involves Kenji having twisted him into the alternate reality where the 4333A is the best JBL, ever, and the only one with forever crossovers that need no upgrading due to their use of polyester-film caps. No other can compare. Now another member pops up with the Kenji "upgrade" to what he refers to as "KRS Artificial Leather" surrounds. I assume KRS is shorthand for KenRickSound, but . . . why do it?

Anyone know anything about these? How they affect the driver's performance parameters? Durability? Anything? My assumption is it's an attempt to improve on the lifespan of foam surrounds for Kenji's well-heeled clients. But what does it do to the sound? Seems to me it would be as heretical as an off-brand re-cone.

http://img05.shop-pro.jp/PA01015/403/etc/edge2.jpg

[grumpy]

Without measurements and listening, who knows...

That said, there were quite a few early drivers that had actual leather surrounds (and often phenolic, spiders... which makes the name make a little more sense looking at them... whether it had anything to do with it or not).

I've always assumed lansalloy was an attempt at an artificial leather surround with good self damping properties and without the upkeep (oops).

No real comment about the properties of a new pleather(?) surround.

[hjames]

because there is an almost mystical kinship with ... Leathah!


The large thread over on AK about an owner's latest "dream system" (second this year) involves Kenji having twisted him into the alternate reality where the 4333A is the best JBL, ever, and the only one with forever crossovers that need no upgrading due to their use of polyester-film caps. No other can compare. Now another member pops up with the Kenji "upgrade" to what he refers to as "KRS Artificial Leather" surrounds. I assume KRS is shorthand for KenRickSound, but . . . why do it?

Anyone know anything about these? How they affect the driver's performance parameters? Durability? Anything? My assumption is it's an attempt to improve on the lifespan of foam surrounds for Kenji's well-heeled clients. But what does it do to the sound? Seems to me it would be as heretical as an off-brand re-cone.

http://img05.shop-pro.jp/PA01015/403/etc/edge2.jpg

[BMWCCA]

Here's the sales pitch the owner was given, supposedly by Kenji:

Kenji found them to give much better bass than stock.

Apparently, they've been working on this improvement for a long while before offering it as an upgrade.I wonder how Kenji would define "better"?

[grumpy]

Not arguing for or against, but mo' better bass sounds a little like "coldest beer in town".

If they can sell them (perhaps via demo or word of mouth) without further info,
I'm not going to get all butthurt about it. Would be interesting (for me) to know more
so I don't drop it in the polished/plated 075 category.

(ok... sort of interested. Hasn't motivated me to drive over to AK for a look-see :P)

[JeffW]

Hell, I read the guy's thread and still couldn't rustle up enough outrage to inquire.

[Ian Mackenzie]

If you dismiss the description "leather" an alternative surround is not a new idea.

If you were to regard this as a cloth surround for all intensive purposes it may well do some things better.

Jbl have after all used cloth surrounds in recent times.

It may well (leather) be less prone to pumping on large excursions where a foam surround would literally balloon rather than see air pressure in the port. The losses Q? in the surround may have a dynamic impact under those conditions Foam is better for controlling boundary reflections as sound waves move out to the edge of the cone.

I have heard some some full range drivers with leather surround recently so leather is out there.

That is my educated guess. Make the driver a better air pump.

But it might be a case of plecibo (aka visual) on the part of the user that dominates what the ears hear

[gdmoore28]

Ian, I'm not a word Nazi, but I had quite a stumble over the "intensive purposes" in your post. Is that intentional, or did you mean "intents and purposes?"

GeeDeeEmm

[Ian Mackenzie]

I meant the latter but read this

"for all intensive purposes"

"Both for all intents and purposes and for all intensive purposes are widely used to mean “for all practical purposes” or “virtually".

For all intensive purposes is a fairly common eggcorn derived from the original phrase. It’s often heard in speech, but it’s rare in published writing because it generally doesn’t pass through the editorial process."

Just throwing it out there

I admire Kenji for differentiating himself in the market and if this bring joy to some of his customers then that is a good thing ( in an otherwise compromised set of circumstances)

(Auto word correct on the iPhone and my dog licking me can result in a loss of exact meaning)

[hjames]

Its not actually leather, but a synthetic leather of some kind ...
No pro or conning it, I'm just sayin'

[Lee in Montreal]

I have (almost) 40 years old Butyl surrounds on several of my KEF woofers and they are still like new. I was always amazed that JBL produced foam surrounds that start deteriorating the day they are made. Even being kept in storage in a box. If synthetic leather works better and last longer, then why not?

http://usr.audioasylum.com/images/y2012/10/72616/IMG_1826.JPG

[hsosdrum]

While I was working at Harman, I had many discussions with Greg Timbers and Jerry Morro about speaker (transducer) design, and both told me that the construction and materials in a speaker's surround have a very large impact on its performance. (I specifically remember Jerry telling me that the treated accordion surround of the 2213Nd-2 woofer in the 4312E was "more than 30% responsible" for the transducer's overall performance.) Changing the surround material (i.e. from foam to leather), its construction (from 180-degree roll to 135-degree roll, or to accordion, or from untreated accordion to treated accordion) or its physical properties (i.e. its compliance) will significantly alter the transducer's performance. And the full extent of these changes is almost always unpredictable, since the transducer's physical elements all interact and affect each other's physical performance.

As Grumpy said, measurements should reveal how the new surround actually affect's the woofer's performance. Without measurements, any simple pronouncement that the sound is "better" is always a matter of opinion. (When was the last time any of us blindly accepted another audiophile's opinion that something sounded "better" without first listening to confirm it for ourselves?)

But just as important, even if the mod does measure and sound "better", is it repeatable? Can subsequent leather surrounds be manufactured with tolerances tight enough to ensure that the resulting woofer performance will duplicate that of the measured prototype? Absent such repeatability, any such modification, no matter how much "better" it sounds, should be considered a "one-shot deal". Considering that "leathah" is a natural material that is subject to natural variations in density and rigidity, and that the surrounds are hand-made and subject to the small variations attendant to all hand-made products, I have my doubts that it's possible to create multiple leather surrounds with physical properties similar enough to ensure consistent woofer-to-woofer performance.

Edit: This was written before Heather's post about the surrounds being synthetic leather. Nonetheless, my feelings about it are the same.

[BMWCCA]

Edit: This was written before Heather's post about the surrounds being synthetic leather. Nonetheless, my feelings about it are the same.The term used by the owner of the system, and Kenji, and in the title of this thread was and is "artificial leather".

I have to wonder if the Russians have figured out this "new" technology yet? ;)

[lordoflight]

Is there a way to "soften" the surrounds in order to get more bass?

[hjames]

Is there a way to "soften" the surrounds in order to get more bass?
Most people add a subwoofer to get more bass ...
rather than try to tweak the speaker (driver) design ...

[BMWCCA]

Is there a way to "soften" the surrounds in order to get more bass?Maybe more flabby bass? :dont-know:

[Lee in Montreal]

Is there a way to "soften" the surrounds in order to get more bass?

It depends. Do you have old woofers on which the accordeon fabric suspension has stiffened over time? If it's the case, then sure, there are ways to soften the suspension to bring the woofer back to original specs.

[lordoflight]

I have a new 2235 recone kit from SS audio installed on an E140 chassis. I was wondering if softening the foam surround somehow will improve the bass.

[hjames]

I have a new 2235 recone kit from SS audio installed on an E140 chassis. I was wondering if softening the foam surround somehow will improve the bass.

So - most folks with new surrounds talk about break-in time before they reach the expected sound.
Since JBL did not sell replacement surrounds, and recommended recones when surrounds aged and failed,
it may depend on what materials were used in your non-factory replacement parts.

If you decide to try and apply some material/compound to change the sound, suggest that you run tests before and after
and see what you think.

[1audiohack]

I have a new 2235 recone kit from SS audio installed on an E140 chassis. I was wondering if softening the foam surround somehow will improve the bass.

The foam surround on a 2235 has little effect on the Fs.

In the thread "Butyl Rubber Surrounds from Japan" the measured difference from surrounds old and new and none are posted. The effect from none to new is only several Hz.

If I were looking to mod the bass output of a 2235 I would look elsewhere.

Barry.

[Lee in Montreal]

If I were looking to mod the bass output of a 2235 I would look elsewhere.

Barry.

Indeed. Especially that the 2235 is known to have a great bass. I suggest the problem is not the woofer. Too much mids? Too much highs? Bad room?

[gdmoore28]

I meant the latter but read this

"for all intensive purposes"

"Both for all intents and purposes and for all intensive purposes are widely used to mean “for all practical purposes” or “virtually".

For all intensive purposes is a fairly common eggcorn derived from the original phrase. It’s often heard in speech, but it’s rare in published writing because it generally doesn’t pass through the editorial process."

Just throwing it out there


(Auto word correct on the iPhone and my dog licking me can result in a loss of exact meaning)

I'd never seen it used before, but I really liked the immediate visual image that it brought to mind. I immediately imagined a group of technicians in white lab coats running around in circles with "intense purposes" as they tried to solve a problem. My addled mind. I really thought that you might have stumbled on a new twist on the words, but I guess somebody else beat you to it. Drats. Nonetheless, I like it and will be looking for creative ways to use it. And thanks for not taking offense. I certainly meant none.

(And I certainly understand the dog issue. My dog is resting on my lap as I type this using a keyboard that is clogged with dog hair and morsels of dog treats. That scenario has resulted in more than one typo, I can assure you. :) )

GeeDeeEmm

[lordoflight]

I think bad room is indeed the issue. When I moved in my new home with my old proacs which had a lot of bass in the concrete walls 21 sqm room Now in my new plaster walls 60 sqm room the bass is gone. I thought replacing them with a pair of good ol 43xx jbl will do the trick due to the large 2235s and boy I was wrong. The bass is nowhere to be found.

[Ian Mackenzie]

Then go up to the 18 (2245H)

[Ian Mackenzie]

Hi GeeDeeEmm,

Far from being a literary expert but l think in terms of English grammar.

The egg corn you picked up on is said far more than it is written.

Of course how ones thoughts are said and written is about style.

Someone recently compared my style to Vollmann which is hilarious if you ever read his bio.

My first article which l wrote 20 years ago for the Melbourne Audio Club magazine was lifted and published by the editor of Australian HFi Greg Borrowman.

The article caught Borrowman's eye as l used the JBL slogan "nothing even comes close " referring to how the JBL 4343 monitor can play any kind of music at almost realistic volume levels which of course the average hifi shoe box won't do. That caused a stir in the annals of the oldest Hifi club in the world (founded by Alex Encel).

I try to be clear and concise but l do tell it as is if the need calls for it!

[Lee in Montreal]

Then go up to the 18 (2245H)

or put some carpets on the floor and stuff on the walls to reduce reverberation and abundance of mids...

btw 60sq.m is 645sq.ft - That's also a large room.

[bldozier]

That be assault and battery, not an interior decorator. ☺

[toddalin]

I have a new 2235 recone kit from SS audio installed on an E140 chassis. I was wondering if softening the foam surround somehow will improve the bass.



Do you know that they installed the mass ring when reconing the speakers? This will increase the bass at the expense of tightness in the lower midrange.

There is something that you can do to increase the deep bass, but most no-one here, other than me, would think about doing it (and it does work).

You can put a 100 watt non-inductive resistor in series with the woofer and reduce the mids and highs by ~3.5 dBA.

This works because of the inherent impedience spike in the deep bass range. Here the impedience can be >30 ohms. So when 8 ohms is added to 30 ohms, the volume decreases by 1.0 dBA. But when added to the ~7 ohms though most of the bandwidth, it decreases by ~3.5 dBA and if you turn the volume up by 3.5 dBA to compensate for this, you've increased the deep bass by 2.5 dBA relative to the bandwidth.

It does work and if you like the sound...

[berga12]

I think bad room is indeed the issue. When I moved in my new home with my old proacs which had a lot of bass in the concrete walls 21 sqm room Now in my new plaster walls 60 sqm room the bass is gone. I thought replacing them with a pair of good ol 43xx jbl will do the trick due to the large 2235s and boy I was wrong. The bass is nowhere to be found.


You can't compare Room Vs Room with different speakers....

you have to check for bass cancellation, for sure you have.

1st test, walk inside the room,between speakers, in the corner, on the back wall etc....to find "the bass", in the bigger room you have more problems than in the small one, much more problems.....you need acoustic correction.

I had the same problem. No bass at 4,5meter, huge bass at 5meter, tremendous bass in the 2 front corner, right bass between the speakers.





About Leather sorround, would be nice if Kenji-san post the 2235h T&S measures, if the value are comparable, why not evaluate an alternative or give a try...