info please

[itssmoke]

hello. maybe someone knowledgeable can help me. im looking for a (any)product used to treat a speaker cone. ive heard manufactures refer to a speaker as "treated paper cone" or "doped". i know ads used a "sticky" coating on their speaker domes,,, polk used a coating that dried and was not sticky, for examples. has anyone had any experience with such a product? what effect in performance was noticed? where can i find such a product? thanks . any help is appreciated. best regards

[ThomasW]

What do you want the coating to do?

[itssmoke]

hello. could it help with brightness? i always thought that was the purpose or those type coatings, secondarly would be durability. ?? what has been your experience with that(any) type coating? thanks

[collo]

A friend of mine coats his paper cones with PVA glue. He says it makes them stiffer, particularly for a woofer that's got a few miles on it..

[itssmoke]

im dealing with a midrange.. paper cone.. thats good but a little too bright. i was wondering if a coating would help to tame it somewhat. budget constraints wont allow for purchases for this project right now. i was looking for substitute that would fill the bill for a while. i thought maybe id get lucky and stumble into the right fit, with some components i had on hand. i really dont want to re-work the crossover. im actually close to what i need if i can subdue this brightness.

[Hdale85]

You could coat it but more then likely will change the specs some. Most of the people on these forums use metal cones so not sure how much info your going to get related to paper cones.

[joecarrow]

Do you have any EQ available to you? One problem with coatings is that it's not reversible, so if it makes things worse- too bad.

Your perception that it's "too bright" could come from a lot of things. It could be cone breakup that's not caught by an inadequate crossover. It could be a plain-old peak in response. It could be that the crossover doesn't account for baffle step properly.

Some things that I would try before coating it would include:
-Try surrounding the face of the cabinet around the mid with a heavy felt
-Try hanging sound absorbers on your walls to cut down on reflected mid/high content. These could be as simple as blankets or decorative rugs
-If they are presently toed in, try aiming them straight ahead, or away from the listening position somewhat
-Try changing the room placement, closer to or farther from rear/side walls

As a last resort, you can try coatings or glues.

[itssmoke]

i have no eq , and i wont be losing much if this mid driver dosent like a coating. the crossover is set up properly for the cabinet (baffle). a very good crossover , quality components thru and thru. i could be dealing with a impedence issue. the crossover is set for 4 ohm driver in the mid section,, this particular driver is a much lower impedence (1 ohm). i was trying to make due with this until i manage the funds for a correct replacement.i was just thinking out loud here and wondering if a coating could tame the response a little. i guess i could add another resistor ,, but i would have to trial and error the values , or maybe a coating and resistor addition both. do you know the names of good coatings?

[joecarrow]

It can not be a good crossover unless all of the drivers used are the specific drivers that the crossover was designed for. The exception is if the driver matches impedance, phase, SPL, distortion, dispersion, and most thiele-small parameters within a fairly close tolerance. The only example I'm aware of where this can generally happen is when a manufacturer either copies another's driver design, or if they duplicate their own part with a different part number.

You would be better off saving up and getting the exact mid that the crossover was designed for.

[ThomasW]

Without specifics of the drivers, crossovers, etc, and some frequency response plots showing the problem, all this is simply guessing...

Also the application of some random generic coating is as likely to make the driver worse as it is better.

[itssmoke]

thanks guy's . like i said i was just talking out loud. what i need is a pair of scanspeak 13m-8531 ,, 4 ohm . the crossover is correct for the cabinet design(baffle) and that specific mid. i was just trying to get resonable results until i get lucky on those scanspeak mid's. do you happen to know where there would be a pair , working or not , for reasonible price? i think that the problem im having is SPL. i am not an expert , i will listen closely to what an expert says. i appreciate everyones help. thanks