View Full Version : Lansaplas

Rex Mills
06-07-2003, 10:43 AM
I frequent the forum for various reasons. Among them are an education provided very generously by the forum members and for entertainment and an occasional giggle, particularly in the last couple days:) But I need some clarification about something. Lansaplas is mentioned often but I seem to remember JBL used a similar coating called Auqaplas years ago. What, if any, are the differences between the two? Just marketing lingo for the same thing or a real difference between the two? What EXACTLY does Lansaplas consist of ?

Earl K
06-07-2003, 11:50 AM
Hi Rex
RobH and I went through this a while back in one of the older forums ( lost in one of the crashes ) - they are apparently the same thing - just a different marketing name. I'll let Rob expand on that info if there is more to it. JBL uses "Polyplas" also , though I don't know where it fits in the scheme of things.

What is it ? I always thought it was a thick, paint-on , goopy, water-borne plastic ( if correct, making it a cousin of latex paint ) . Seems that JBL has maybe trademarked use of the name, though I've seen old Altec references to it - used on their old horns ( multicells or the 311 - maybe the first generation of MantaRays ).

Here's a link to Piedmont Plastics (http://www.piedmontplastics.com/prodtype.asp?ID=5&TYPE=136) that doesn't seem to support my water-soluable contention. Their Aqua-plas is PVC based .

In addition to being added to the usual woofer suspects, JBL has a light "dusting" of it on the 2450SL titanium, 4" diaphragm ( plus the 275nd - 1.75" & 435Be - 3" diaphragms ). If it's a newer K2 speaker - you'll find judicious use of this dampening compound in the transducers moving parts. The dome weight of the 2450SL is 75% titanium with 25% plastic - so the literature suggests. For the last 7 weeks I've been listening to a pair of the 2450Sl diaphragms ( in 2440 motors ) and this coating/mixture does make a difference to the dampening characteristics of the 4" diaphragms resonances. I can't decide if I prefer it to Altecs' nicely damped 288 aluminum diaphragms. This JBL does have more HF extension. But, that's a different story .

regards <> Earl K

06-07-2003, 03:20 PM
Hello Earl

My take is they are not the same. Could be wrong but hear goes. The lansaplas seems to be a white spayed on topical coating. The aquaplas seems to be a laminate or is integrated in the cone and is not vissible. Could be the same base material but applied differently as a coating and as a laminate.

Don't know what's in the lansaplas it seems to have a silica or sand as part of it. Other than that???

The aguaplas has been around for a while. Google Search


Aquaplas: A strong lightweight cement developed for aerospace applications. Allows speaker cones to maintain their shape regardless of output level.

Another application In Submarines


The ensuing tests emphasized sound reduction and included extensive evaluation of Aquaplas, a sound dampening plastic which had been applied to the ship's superstructure and tank interiors. In October 1958, her bow planes were removed to cut down still more on noise. The submarine ended the year with a fortnight's run to Halifax, Nova Scotia, and back to serve as a target ship for Canadian warships.


Earl K
06-07-2003, 04:35 PM
Hi Rob
Oops, yer right, I forgot about that grit in the Lansaplas coating.
So if it's white do you want to call it Lansaplas and leave the Aquaplas moniker for the dark stuff ?
regards <> Earl K :)

- may have to modify that thought, I was just looking around the Lansing library and JBL refers to the white coned le14h in the Oracle L220 as Aquaplased. I do notice my old le10a & le14a have a different texture coating than the ferrite models of the same speakers. Maybe the conversion to ferrite magnets influenced a new formulation for the stuff / and then a name change .

06-07-2003, 07:49 PM
Hello Earl

You are right says the same thing in the L250 sheet black aquaplass front and back.

"Maybe the conversion to ferrite magnets influenced a new formulation for the stuff / and then a name change ."

I have a 128H-1 that looks the exact same as an Le-14A but black and a 129H with a white back also the same??

Hello Rob

Yes I have seen the green Heathkit models. So what do you think same stuff just changed names?? Same stuff different applications?? One topical the other inside??

I have been looking at my Le-14A's and the 123A , 115H, 122A, and 129H backside all white all looks the same. With that white grit with shinny bits hear and there. The 128H-1 look to be the same material just black. My 116H, 127H and weird Le-14A recone all have stiff cones with no obvious coating. The aquaplas must be inside the cone as a laminate or just mixed in maybe as a binder?

Ok who do we have to call at JBL:D to figure this one out??


Rex Mills
06-07-2003, 07:50 PM
I have seen some 1970s vintage woofers in Lafayette Criterion loudspeakers that had a coating that looked and felt exactly like Lansaplas.It was dark gray, as I remember. Maybe these cones were made by JBL's supplier also back them.
That brings back memories of sitting in study hall in Jr. high drooling over Allied catalogs trying to decide which 12 inch coax and cabinet I would buy when I had enough money saved up.:) OOPS, back to the real world.
Thanks for the discourse guys:)