Paint speakers to lower fs

[Chuckles]

I'm building some line arrays for my backyard using NSB's with separate tweeter arrays.

I think painting the NSB's would look better, the metal frames would look better black, and since they will spend a lot of time exposed to the sun, paint might protect the paper cones, and adding to the mms a little bit might help lower fs.

I plan on using some kind of spray paint, but what type? enamel, lacquer, latex, not sure, any suggestions?

[Chris Roemer]

If they'll be in the sun, I'd paint them white (much less heating by reflecting the sun, rather than having the black absorb it). Something black in the sun (like a railing, or door handle) gets too hot to even touch. The less weight (mass) your paint has, the better.

[AEIOU]

I'm building some line arrays for my backyard using NSB's with separate tweeter arrays.

I think painting the NSB's would look better, the metal frames would look better black, and since they will spend a lot of time exposed to the sun, paint might protect the paper cones, and adding to the mms a little bit might help lower fs.

I plan on using some kind of spray paint, but what type? enamel, lacquer, latex, not sure, any suggestions?

You have to be really careful to not get any paint on the surrounds, otherwise you stand a good chance of wrecking them. The solvents in spray paint can soften the glues used to assemble the drivers. I suggest not painting them or practice on only one before attempting to paint the entire lot.

[PWR RYD]

You have to be really careful to not get any paint on the surrounds, otherwise you stand a good chance of wrecking them. The solvents in spray paint can soften the glues used to assemble the drivers. I suggest not painting them or practice on only one before attempting to paint the entire lot.

Good advice.

[billfitzmaurice]

I wouldn't bother trying to lower the Fs, since subwoofers will still be required to handle the lows. A clear acrylic coating of the cones would add a measure of moisture resistance. One nights deposit of dew could ruin them. Before you get too far along I'd suggest that a single line of midbasses is sufficient, especially considering how many of them you're using.

[Chuckles]

Thanks for the responses, I'll give acrylic a shot. I have a few extras.

Lowering the fs isn't necessarily for lower extension.

I haven't built anything with the NSB's in a long time, I remember there being a peak in response up near or past where they will be crossed over. I thought adding some weight would tame that.

They will be without woofers probably until next year, they will be in the garage with a subwoofer, but I will pair them with 8 15" woofers.

[billfitzmaurice]

My NSB line arrays are crossed at 4kHz, with 3rd order filters. They don't have a response peak.

[chad1376]

Think about speaker grilles with guitar-type cloth. It shouldn't affect sound much, it would block a lot of UV and help protect the speakers from flying objects. Grills might also help protect against light rain (as long as wind isn't blowing the rain sideways.) Screen door frame kits would make a weather resistant grill frame. If at any time you have small kids in the yard, they will poke the dust caps. It's in their genes.

I'd probably hit the cones (only) with a light coat of clear rattle-can enamel, just to help protect them from moisture.

Oh yah, knowing the NSB's are NLA...Do you have spares? They'd be good to have around if someone pokes a stick in a cone, or you over-cook a voice coil.

[1100xxben]

Think about speaker grilles with guitar-type cloth. It shouldn't affect sound much, it would block a lot of UV and help protect the speakers from flying objects. Grills might also help protect against light rain (as long as wind isn't blowing the rain sideways.)...

UV stable filter foam is what you want. It is very acoustically transparent and will shed water very well. I've even seen demos where the thicker stuff can take a garden hose spraying at it, and all the water will shed down to the bottom, with nothing getting through. It will also help keep larger bugs out.

Edit: I forgot, PE sells the stuff. https://www.parts-express.com/parts-...black--260-519
3/8" is a little thin, but it's a LOT better than nothing. I also don't know if that stuff is UV stable.

[chad1376]

Another thought...doors sealed with weatherstrip foam, or just a removable hard cover. Keep the speakers sealed up unless you're actually listening to them. Grills, in addition, would still be a good idea, since I'm assuming these will be kinda like "party" speakers, and used with drunken adults, kids (and maybe dogs?) in close proximity.

[Chuckles]

I am really thinking about going with some kind of grill now. On the back deck they will eventually have their own shed type enclosures that I pull them out of.

I have a few boxes of NSB's leftover. You know how some people draw a line every year to track the growth of their children, I tracked it by how far they could reach up to poke the dustcaps on the NSB arrays I had.

The tweeters are where the money is though. The baby won't be able to reach them and the older ones know better.

[dlr]

I'm building some line arrays for my backyard using NSB's with separate tweeter arrays.

I think painting the NSB's would look better, the metal frames would look better black, and since they will spend a lot of time exposed to the sun, paint might protect the paper cones, and adding to the mms a little bit might help lower fs.

I plan on using some kind of spray paint, but what type? enamel, lacquer, latex, not sure, any suggestions?

You're thinking of actually painting the driver cones? No matter how you treat the diaphragm, it's bound to alter the respond and not necessarily in a good way. Two things occur. One is reduced sensitivity. You'd be surprised how little added mass can reduce sensitivity be several db. Sure, it will reduce Fs, but mass is mass and sensitivity is highly dependent on mass.

Second is wildly differing resonance changes. Coatings are likely to add to and/or exacerbate resonances. Hard drying coatings are more than likely going to be worse because they will likely reduce the self-damping of the cone and more likely (IMO) to add resonances. Soft coatings may damp some resonances, but can still add to or exacerbate existing ones. But without question, any added coatings will add mass and therefore reduce sensitivity. The only question on that aspect is to what degree.

One other issue is driver-to-driver consistency. Applying a coating uniformly to a number of drivers will be very difficult IMO. Even if you apply the same mass to each, not an easy task, either, the resulting change in the resonant nature could be a lot different between drivers.

Trial and error testing, with measurements, is the only way I would consider any driver modifications. Be ready to throw away any you test if the change is permanent.

dlr

[chad1376]

... You know how some people draw a line every year to track the growth of their children, I tracked it by how far they could reach up to poke the dustcaps on the NSB arrays I had.....

I'm with you. The arrow indicates how tall my kids were when they stopped poking speakers. You can's see it, but every tweeter dust cap below is pushed in.



New version: Expanded metal grate. Not so much to protect against fingers, but rather flying wrenches when car repairs go awry. These obviously aren't subject to sun and rain though.